Operational Management Essay Example | Topics and Well Written Essays - 250 words

Operational Management - Essay Example The company should also be focused on material flow and this increases the liquidity of assets and hence reduces the chance of obsolesce. This can also be dealt with by reducing defects and this ensures that fewer cars are taken back to the factories to rectify the defects. Aligning the metrics in any company has been seen to be crucial in ensuring efficient production. This was demonstrated well by Alfred Sloan where managing the cost of production is key. Having a lean organization where all the resources are used to the maximum is the driving force of success. Currently GM produces approximately 6.1 million unit products annually. If the company takes measure to improve the inventory turnover ratio, this can boost production making the company to increase productivity with 25%. It could thus be possible for GM to produce 7.625 million unit products with its current resources. This would result in increased sales turnovers as their automotives do not stay in stock for a long

Normative Relativism Ethical Theory Essay Example | Topics and Well Written Essays - 750 words

Normative Relativism Ethical Theory - Essay Example The ethical theory that I will apply is one whereas an individual running an organization as a youth group with a diversity of members. Some of the members are Christians, others Muslims and others are not religious. Due to the differences in religious orientations of the members, there are issues during discussions and joint functions since some members perceive themselves as better people and more morally upright compared to their counterparts of different religions. This has lead to many decisions being viewed as biased and not accepted by all the members hence growth and nurturing of conflicts and strife. The ethical theory that is to be presented is a normative relativism and it indicates that every individual has what or to what extent he feels that an issue is morally okay hence it cannot be judged against him when he fails to meet the expectations and targets of the society. This is a big dilemma to the judging of individuals since every person has a benchmark of whatever he feels is quantified as ethical moral. My ethical theory is for the search of what is morally right for the society despite the constraints and upheavals facing the society at present and in the past. It, therefore, is a representative of normative ethics hence it will be showing a judgment of what is right or wrong as it occurs within the social ranks. It will examine the virtues, norms, and values attached to the social issues and how the society generally implements the issues. The ethical theory that I present above is one that represents the value ethics of the society in relation to the judgments of issu es in a way that is morally friendly and without compromising the rights and actions of the other individuals.

Study Of Attacks On E Commerce Systems Computer Science Essay

Study Of Attacks On E Commerce Systems Computer Science Essay Electronic commerce (e-commerce) services nowadays have become a core element and more popular on Internet and Web environment. Electronic commerce, Internet and Web environment have enabled businesses to reduce costs and offer many benefits both to the consumer and to the business. According to Forrester Research the online retail sales in the United stated for 2003 exceeded $100 billion. As the Information Technology and the using of internet are increasing every day, the demand for secure information and electronic services is growing. Every online transaction in the internet can be monitored and stored in many different locations, since the Internet is a public network it makes very important for businesses to understand possible security threats and vulnerabilities to their business. The key factor that affects the success of e-commerce is to exchange security on network. In this paper we will describe some of the security threats and vulnerabilities concerning the e-commerce se curity. Keywords: e-Commerce security, threats, vulnerability, attacks 1. Introduction The improvements that Internet has made during the past few years have changed the way people see and use the Internet itself. The more their use grows, the more attacks aim these systems and the amount of security risks increases. Security has become one of most important issues and significant concern for e-commerce that must be resolved [1]. Every private and public organization is taking computer and e-commerce security seriously more than before because any possible attack directly has an effect in E-commerce business [5]. The Internet and Web environment can provide as many security threats and vulnerabilities as opportunities for a company. The low cost and high availability of the world wide Internet for businesses and customers has made a revolution in e-commerce [1]. This revolution in e-commerce in turn increases the requirement for security, as well as the number of on-line cheats and fraud as it is shown in the Figure 1. Although there has been investments and spent a very large amount of time and money to provide secures networks, still there is always the possibility of a breach of security [5]. According to IC3 2007 annual report, the total dollar loss from all referred complaints of fraud was $239.09 million [3]. The majority of these frauds and cheats were committed over the Internet or similar online services. Security is still a significant concern for e-commerce and a challenge for every company. Mitigate security threats and vulnerability is still a battle for every company [5]. Good security infrastructure means good productivity for the company. Figure 1: Incidents of Internet fraud [15] In this paper in the first section we will give a brief describe of e-commerce and the types of e-commerce, and then in second section we will describe the security issues and some of the threats and vulnerabilities- attacks in e-commerce. Last section discuss various defence mechanism uses to protect e-commerce security which is still high concerns of business. 2. E-commerce Background Information and communication technology has become more and more essential and integral part of businesses. This highly uses of information technology have changed the traditional way of doing business. This new way of doing business is known as Electronic Commerce (E-Commerce) or Electronic Business (E-Business) [12]. Electronic commerce or e-commerce means buying and selling of products or services over the part of internet called World Wide Web. According to Verisign [2004] electronic commerce is a strategic imperative for most competitive organisations today as it is a key to finding new sources of revenue, expanding into new markets, reducing costs, and creating breakaway business strategies. E-commerce includes electronic trading, trading of stocks, banking, hotel booking, purchases of airline tickets etc [2]. There are different types of e-commerce, but we will encompass the e-commerce on there types of business transaction: B2B ( business to business); B2C ( business to consumer); C2C (consumer to consumer) [4]. Business to Business (B2B) e-commerce- is simply defined as commerce transactions among and between businesses, such as interaction between two companies, between e manufacturer and wholesaler, between a wholesaler and a retailer [16]. There are four basic roles in B2B e-commerce suppliers, buyers, market-makers and web service providers. Every company or business plays at least one of them, and many companies or businesses play multiple roles [9]. According to the Queensland governments department of state development and innovation [2001] B2B ecommerce made up 94% of all e-commerce transactions [8]. The good examples and models of B2B are the companies such IBM, Hewlett Packard (HP), Cisco and Dell. Business-to-Consumer (B2C) e-commerce- is the commerce between companies and consumer, businesses sell directly to consumers physical goods (i.e., such as books, DVDs or consumer products), or information goods (goods of electronic material digitized content, such as software, music, movies or e-books) [10]. In B2C the web is usually used as a medium to order physical goods or information goods [8]. An example of B2C transaction would be when a person will buy a book from Amazon.com. According to eMarketer the revenue of B2C e-commerce form US$59.7 billion in 2000 will increase to US$428.1 billion by 2004 [10]. Consumer to Consumer (C2C) e-commerce- this is the type of e-commerce which involves business transactions among private individuals or consumers using the Internet and World Wide Web. Using C2C, costumers can advertise goods or products and selling them directly to other consumers. A good example of C2C is eBay.com, which is an online auction where costumers by using this web site are able to sell a wide variety of goods and products to each other [6]. There is less information on the size of global C2C e-commerce [10]. Figure 2 illustrates some of the e-commerce business describe above. Figure 2: Common e-Commerce business model [14] 3. Security threats to e-commerce Security has three basic concepts: confidentiality, integrity, and availability. Confidentiality ensures that only the authorized persons have access to the information, not access for the unauthorized persons, Integrity ensures the data stored on any devices or during a communication process are not altered by any malicious user, Availability ensures that the information must be available when it is needed [16]. Security plays an important role in e-commerce. The number of online transaction last years has a tremendous increase; this has been accompanied by an equal rise in the number of threats and type of attacks against e-commerce security [13]. A threat can be defined as the potential to exploit a weakness that may result in unauthorised access or use, disclosure of information or consumption, theft or destruction of a resource, disruption or modification [8]. E-commerce environment has different members involved E-commerce network: Shoppers who order and buy products or services Merchant who offer products or services to the shoppers The Software (Web Site) installed on the merchants server and the server The attackers who are the dangerous part of E-commerce network Looking on the above parties involved in the e-commerce network, it is easy to see that malicious hackers threaten the whole network and are the most dangerous part of network. These threats on e-commerce can abuse, misuse and cause high financial loss to business. Figure 3 briefly displays the methods the hackers use in an E-commerce network [11]. Figure 3: Target points of the attacker [11] The assets that must be protected to ensure secure electronic commerce in an E-commerce network include client (shopper) computers or client-side, transaction that travel on the communication channel, the Web site on the server and the merchants server- including any hardware attached to the server or server-side. Communication channel is one of the major assets that need to protect, but it is not the only concern in e-commerce security. Client- side security form the users point of view is the major security; server-side security is a major concern form the service providers point of view. For example, if the communication channel were made secure but no security measure for either client-side or server-side, then no secure transmission of information would exist at all [1, 2]. According to Figure 3 above there are some different security attack methods that an attacker or hacker can use to attack an E-commerce network. In the next section we will describes potential security attack methods. 4. Possible Attacks This section overviews and describes various attacks that can occur in the sense of an e-commerce application. Moreover, ethical aspects are taken into consideration. From an attackers point of view, there are multiple actions that the attacker can perform, whereas the shopper does not have any clue what is going on. The attackers purpose is to gain access to each and every information in the network flow from the when the buyer has pressed the buy button until the web site server has responded back. Furthermore, the attacker tries to attach the application system in a most discrete and ethical way. An onview of various attacks on ecommerce are given: Tricking the Shopper: One very profitable and simple way of capturing the shoppers behaviour and information to use against the attacker is by tricking the shopper, which in other words is known as the social engineering technique. This can be done in various ways. Some of them are: An attacker can call the shopper, representing to be an employee from a shopping site to extract information about the shopper. Thereafter, the attacker can call the shopping site and then pretend to be the shopper and ask them for the user information, and further ask for a password to reset the user account. This is a very usual scenario. Another example would be to reset the password by giving information about a shoppers personal information, such as the date of birth, mothers maiden name, favourite movie, etc. If it is the case the shopping websites gives away these information out, then retrieving the password is not a big challenge anymore. A last way of retrieving personal information, which by the way is used a lot during the world wide web today, is by using the phishing schemes. It is very difficult to distinguish for example, www.microsoft.com/shop with www.micorsoft.com/shop . The difference between these two is a switching between the letters r and o. But by entering into the wrong false shop to pretend to be an original shop with login forms with password fields, will provide the attacker all confidential information. And this is performed if the shopper mistypes this URL link. The mistyped URL might be sent through email and pretend to be an original shop without any notice from the buyer [11, 15]. Password Guessing: Attackers are also aware of that is possible to guess a shoppers password. But this requires information about the shopper. The attacker might need to know the birthday, the age, the last name, etc. of the shopper, to try of different combinations. It is very common that the personal information is used into the password by many users through the internet, since they are easy to be remembered. But still, it needs a lot of effort from the attackers view, to make a software that guesses the shoppers password. One very famous attack might be to look up words from the dictionary and use these as passwords, this is also known as the dictionary attack. Or the attacker might look at statistics over which passwords are most commonly used in the entire world [15]. Workstation Attack: A third approach is to trying to attack the workstation, where the website is located. This requires that the attacker knows the weaknesses of the workstation, since such weak points are always presented in work stations and that there exist no perfect system without any vulnerabilities. Therefore, the attacker might have a possibility of accessing the workstations root by via the vulnerabilities. The attacker first tries to see which ports are open to the existing work station by using either own or already developed applications. And ones the attacker has gained access to the system, it will therefore be possible to scan the workstations information about shoppers to retrieve their ID and passwords or other confidential information. Network Sniffing: When a shopper is visiting a shopping website, and there is a transaction ongoing, then the attacker has a fourth possibility. The possibility is called sniffing. That an attacker is sniffing means that all data which is exchanged between the client and server are being sniffed (traced) by using several applications. Network communication is furthermore not like human communication as well. In a human communication, there might be a third person somewhere, listening to the conversation. In the network communication technology, the data which is sent via the two parties are first divided in something called data packages before the actual sending from one part to another. The other part of the network will therefore gather these packages back into the one data which was sent to be read. Usually, the attacker seeks to be as close as possible to the either the shoppers site or near the shopper to sniff information. If the attacker places himself in the halfway between the shopper and website, the attacker might therefore retrieve every information (data packages). Given an example in this, then assuming a Norwegian local shopper wants to buy an item from a webshop located in the United States of America. The first thing which will happen is that the personal information data which is being sent from the shopper will be divided into small pieces of data to the server located in the USA. Since the data flow over the network is not controlled by the human, the packages might be send to different locations before reaching the destination. For instance, some information might go via France, Holland and Spain before actually reaching the USA. In such a case, the sniffer/attacker was located in France, Holland or Spain, will mean that the attacker might not retrieve every and single information. And given that data, the attacker might not analyze and retrieve enough information. This is exactly the reason why attackers are as close as possible to either the source or the destination point (client side or server side). Known Bug Attack: The known bug attack can be used on both the shoppers site and on the webpage site. By using already developed tools, the attacker can apply these tools to find out which software to the target the server is having and using. From that point, the attacker further need to find patches of the software and analyze which bugs have not been corrected by the administrators. And when knowing the bugs which are not fixed, the attacker will thus have the possibility of exploiting the system [11]. There are still many various of attacks one can do more than these described above. More attacks that be used against ecommerce application could by doing Denial of Service (DOS) attacks where the attacker impact the servers and by using several methods, the attacker can retrieve necessary information. Another known attack is the buffer overflow attack. If an attacker has gained access to the root, the attacker might further get personal information by making his own buffer, where all overflow (information) is transferred to the attackers buffer. Some attackers also use the possibility looking into the html code. The attacker might retrieve sensitive information from that code, if the html is not well structured or optimized. Java, Javascript or Active X export are being used in html as applets, and the attacker might also distort these and set a worm into the computer to retrieve confidential information. 5. Defence For each new attack presented in the real world, a new defence mechanism needs further to be presented as well to protect the society from unsuspicious issues. This section introduce some defence issues how to protect the attacks described in the section before. However, the main purpose from an sellers point of view in an ecommerce application is to protect all information. Protecting a system can be performed in several ways. Education: In order to decrease the tricking attacks, one might educate all shoppers. This issue requires a lot of effort in time and not simple, since many customers still will be tricked by common social engineering work. Merchants therefore have to keep and remind customers to use a secure password since this person is used as the identity. Therefore it is important to have different passwords for different websites as well and probably save these passwords in a secure way. Furthermore, it is very important not to give out information via a telephone conversation, email or online programs. Setting a safe Password: It is very important that customers do not use passwords which are related to themselves, such as their birthdays, childrens name, etc. Therefore it is important to use a strong password. A strong password has many definitions. For example, the length of passwords is an important factor with various special characters. If a shopper cannot find a strong password, then there are many net sites proving such strong passwords. Managing Cookies: When a shopper registers into a website with personal information, a cookie is being stored into the computer, so no information is needed to be entered again at next logon. This information is very useful for an attacker, therefore it is recommended to stop using cookies, which is an very easy step to do in the browser [11]. Personal Firewall: An approach of protecting the shoppers computer is by using a personal firewall. The purpose of the firewall is to control all incoming traffic to the computer from the outside. And further it will also control all out coming traffic. In addition, a firewall has also an intrusion detection system installed, which ensures that unwanted attempts at accessing, modification of disabling of the computer will not be possible. Therefore, it is recommended that a firewall is installed into the pc of a shopper. And since bugs can occur in a firewall, it is therefore further important to update the firewall [11]. Encryption and decryption: All traffic between two parties can be encrypted from it is being send from the client and decrypted when it has been received until the server, vice versa. Encrypting information will make it much more difficult for an attacker to retrieve confidential information. This can be performed by either using symmetric-key algorithms or asymmetric key algorithms [11]. Digital Signatures: Like the hand signatures which are performed by the human hand, there is also something known as the digital signature. This signature verifies two important things. First, it checks whether the data comes from the original client and secondly, it verifies if the message has been modified from it has been sent until it was received. This is a great advantage for ecommerce systems [11]. Digital Certificates: Digital signature cannot handle the problem of attackers spoofing shoppers with a false web site (man-in-the-middle-attack) to information about the shopper. Therefore, using digital certificates will solve this problem. The shopper can with very high probability accept that the website is legal, since it is trusted by a third party and more legal party. In addition, a digital certificate is not a permanent unlimited time trusted. Therefore one is responsible to see if the certificate is still valid or not [11]. Server Firewall: Unlike personal firewall, there is also something known as the server firewall. The server firewall is an more advanced program which is setup by using a demilitarized zone technique (DMZ) [11]. In addition, it is also possible to use a honey pot server [11]. These preventions were some out of many in the real world. It is very important to make users aware and administrators update patches to all used application to further protect their systems against attacks. One could also analyze and monitor security logs which are one big defence strategy, to see which traffic has occurred. Therefore it is important that administrators read their logs frequently and understand which parts have been hit, so administrators can update their system. 6. Conclusion In this paper firstly we gave a brief overview of e-commerce and its application, but our main attention and the aim of this paper was to present e-commerce security issues and various attacks that can occur in e-commerce, also we describe some of the defence mechanism to protect e-commerce against these attacks. E-commerce has proven its great benefit for the shopper and merchants by reducing the costs, but e-commerce security is still a challenge and a significant concern for everyone who is involved in e-commerce. E-commerce security dose not belong only technical administrators, but everyone who participate in e-commerce- merchants, shopper, service provider etc. Even there are various technologies and mechanisms to protect the E-commerce such as user IDs and passwords, firewall, SSL, Digital certificates etc, still we need to be aware and prepared for any possible attack that can occur in e-commerce.

polio vaccine :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Poliomyelitis (shortened to polio) has been around for thousands of years, and there is still no cure, but at the peak of its devastation in the United States, Dr. Jonas Salk introduced a way to prevent it. Polio attacks the nerve cells and sometimes the central nervous system, causing muscle wasting, paralysis, and even death. The disease, whose symptoms are flu like, stuck mostly children, and in the first half of the 20th century the epidemics of polio were becoming more devastating. Salk, while working at the Virus Research Lab at the University of Pittsburgh, developed a polio vaccine, and the medical trials to prove its effectiveness and safety are still being analyzed.   Ã‚  Ã‚  Ã‚  Ã‚  Fifty years ago the largest medical experiment in history took place to test Salk’s poliomyelitis vaccine. Close to two million children across the United States and Canada were involved in the trial, which was administered by the National Foundation for Infantile Paralysis (NFIP), also known as the March of Dimes. The foundation, created in 1938 by President Franklin D. Roosevelt (a polio victim) and his law partner Basil O’Connor. Across the United States, 623,972 school children were injected with the vaccine or a placebo, using a double blind technique in which neither recipient nor administrator knew which one there were getting. The results, announced in 1955, showed good statistical evidence that Jonas Salk’s â€Å"killed virus† preparation was 80-90% effective in preventing paralytic poliomyelitis.   Ã‚  Ã‚  Ã‚  Ã‚  The statistical design used in the experiment was singular, prompting criticism. Eighty four test areas in eleven states used a textbook model: in a randomized, blinded design all participating children in the first three grades of school (ages 6-9) received injections of either vaccine for placebo and were observed. At the same time though, 127 test areas in 33 states used an â€Å"observed control† design: where the participating children in the second grade received injections of vaccine, no placebo was given, and children in all three grades were then observed for the duration of the polio season. The use of the dual protocol illustrates both the power and the limitations of randomized clinical trials. The control trials with the placebo were important to define the vaccine as the product of scientific medicine, while the observed trials were done to maintain public support for the vaccine.   Ã‚  Ã‚  Ã‚  Ã‚  In 1953, Salk presented his tests of a polio vaccine to the Immunization Committee, the scientific advisory committee for the NFIP. The test results seemed promising to Basil O’Connor, as the children had shown no ill effects and the levels of polio antibodies in their blood had risen. However, several of the senior virologist on the committee questioned the relation of antibodies

Double Jeopardy: Necessary for Justice

This essay will argue that the amendments made to the double jeopardy rule were necessary to improve justice. It will first show that the amendments improve the possibility of achieving justice on principle and for victims by holding the guilty accountable. It will then proceed to examine claims that the implementation of the amendments can create injustice, arguing that the benefits for justice outweigh the costs of such injustices. Thirdly, the essay will discuss how the amendments, including the retrospective effect, improve justice as new DNA evidence is discovered.Finally, it will analyze improvements to justice through the amendments’ positive effects on the justice system. 1. Holding the guilty accountable In the Third Report of the Home Affairs Select Committee, it was stated that ‘the whole point of a criminal justice system is to bring criminals to justice’. The double jeopardy rule contradicts this, giving guilty individuals effective ‘immunity fr om conviction and punishment’ after acquittal. The adjustments hold such individuals legally accountable for their actions indefinitely, as opposed to until the verdict is announced.Hence although it is unlikely that all acquitted criminals will be brought to justice, justice is still improved in principle as they remain liable for their wrongdoings. The most tangible form of justice attainable from the amendments would be for victims and their family and friends. The double jeopardy rule creates an imbalance in the justice system as it protects in absolute terms the rights of the defendant over that of the victim and their families as in the case of Julie Hogg.The availability of appeal for defendants causes further injustice as the double jeopardy rule prevents retrials in the same situations in reverse scenarios. The amendments bring a balance to the justice system by attaining justice for victims and their families and taking their rights into account. 2. Interests of jus tice outweigh potential injustices against defendants There is a need to consider possible injustices against the defendant to ascertain whether such amendments ultimately advance justice, including buse of the amendments by prosecutors and investigators for personal vendettas and the acquitted defendant’s right to ‘repose’ through finality. By allowing only one appeal application and the strict approach towards the appeals process, an abuse of the process without merit would be highly difficult. Absolute finality for the defendant would unjustly give the defendant exclusive immunity. A victim can never be sure that they will not be summoned to testify again in court. The law also does not prohibit civil lawsuits against the defendant, which conflicts with the principles of ‘repose’.As they are not absolute and at times unjust, the abovementioned concerns take a subordinate role in the interests of justice. 3. DNA evidence and need for retrospective inclusion for justice Recent scientific developments could be instrumental in bringing guilty individuals to justice. The House of Commons references a scenario where DNA development caused retrospective identification of a criminal. It is with these developments in mind that amendments to the double jeopardy principle are necessary as it presents opportunities to achieve justice where it was previously impossible.Not including the retrospective provision would be severely unjust as it would cause benefits from the abovementioned developments to be lost and creates ‘arbitrary distinction(s) between persons who happened to have been acquitted before and after the relevant date’. 4. Positive ramifications for the justice system The way the justice system operates and is perceived is essential to the preservation of justice. The appearance of criminals who are untouchable by the law causes the law to look impotent and ‘may undermine public confidence in the criminal justice system’.The amendments to the double jeopardy rule maintain public trust in the justice system, with courts accepting a margin for error. The double jeopardy rule in effect allows a system where ‘judges are unaccountable to the appeal courts as to a crucial aspect of their responsibilities, at the same time providing them with greater powers’. The judicial body can make mistakes and past statistics on successful appeals support this notion. As such, the amendments to the double jeopardy principle improve justice by creating a more accountable system that is open to amendment.In conclusion, the amendments to the double jeopardy rule were a necessity in improving justice and creating more opportunities for justice to be achieved. It is however important to maintain the accuracy of the outcome of the retrials in order to minimize the potential for injustice, and with careful application and implementation of the amendments, the benefits for justice should be significant.BibliographyArticles Barkham, P. The Stephen Lawrence case (1999) The Guardian, http://www. guardian. co. uk/uk/1999/feb/23/lawrence. ukcrime9

Linguistic Research Essay

When does language begin? In the middle 1960s, under the influence of Chomsky’s vision of linguistics, the first child language researchers assumed that language begins when words (or morphemes) are combined. (The reading by Halliday has some illustrative citations concerning this narrow focus on â€Å"structure. †) So our story begins with what is colloquially known as the â€Å"two-word stage. † The transition to 2-word utterances has been called â€Å"perhaps, the single most disputed issue in the study of language development† (Bloom, 1998). A few descriptive points: Typically children start to combine words when they are between 18 and 24 months of age. Around 30 months their utterances become more complex, as they add additional words and also affixes and other grammatical morphemes. These first word-combinations show a number of characteristics. First, they are systematically simpler than adult speech. For instance, function words are generally not used. Notice that the omission of inflections, such as -s, -ing, -ed, shows that the child is being systematic rather than copying. If they were simply imitating what they heard, there is no particular reason why these grammatical elements would be omitted. Conjunctions (and), articles (the, a), and prepositions (with) are omitted too. But is this because they require extra processing, which the child is not yet capable of? Or do they as yet convey nothing to the child—can she find no use for them? Second, as utterances become more complex and inflections are added, we find the famous â€Å"over-regularization†Ã¢â‚¬â€which again shows, of course, that children are systematic, not simply copying what they here. Chomsky’s Influence Research on child language was behavioristic in the years that preceded Chomsky’s critique of Skinner, and his publication of Syntactic Structures: â€Å"though there had been precedents for setting problems in the study of child language acquisition at a more abstract, cognitive level by continental scholars–most notably, Roman Jacobson (e. g. , 1941/1968)–much of the research on child language acquisition at midcentury was influenced to a greater or lesser degree by the highly concrete, behaviorist orientation of B. F. Skinner and others. Two events were of major important in the change from behaviorist to cognitive thinking in research on child language. The first was Chomsky’s classic review (1959) of Verbal Behavior, Skinner’s major book-length work on the learning and use of language; the second Handout for Psy 598-02, summer 2001 Packer Two-Word Utterances 2 was the detailed longitudinal study of the acquisition of English by three young children conducted over a 17-month period by Roger Brown and others in the early 1960s (Brown, 1973). † Ritchie, W. C. , & Bhatia, T. K. (1999). Child language acquisition: Introduction, foundations, and overview. In W. C. Ritchie & T. K. Bhatia (Eds. ), Handbook of child language acquisition, (pp. 3-30). San Diego: Academic Press, p. 3-4 note 2. â€Å"A child who has learned a language has developed an internal representation of a system of rules† (Chomsky, 1965, p. 25). The psychologist’s task, it follows, is to determine what the child’s rules are. â€Å"The linguist constructing a grammar for a language is in effect proposing a hypothesis concerning the internalized system† (Chomsky, 1968, p.23). Up to the 1950s, people simply counted characteristics such as sentence complexity, proportion of grammatical utterances, etc. After Chomsky, the search was on for child grammars, assumed to be universal. Roger Brown’s Research In 1956 Roger Brown heard Chomsky for the first time, speaking at Yale. In 1962 he began a five-year research project on children’s language at Harvard University. The historical significance of Brown’s laboratory at Harvard can hardly be exaggerated. The names of students and colleagues who worked with Brown pop up all the time, to this day, in psycholinguistic research: the list includes Jean Berko Gleason, Ursula Bellugi, David McNeill, Dan Slobin, Courtney Cazden, Richard Cromer, Jill de Villiers, Michael Maratsos, Melissa Bowerman, Eleanor Rosche, Sue Ervin (now Ervin-Tripp), Steven Pinker. Brown set out to write grammars for each of the stages of language development, by looking at the distribution of forms and construction patterns in spontaneous speech. In most cases the data allow for more than one  grammatical description. â€Å"The description to be preferred, of course, is the one that corresponds to the way the speaker’s linguistic knowledge is structured, the one that determines the kinds of novel utterance he can produce or understand, how he constructs their meanings, and what his intuitions are about grammatical well-formedness† (Bowerman, 1988, p. 28) â€Å"Every child processes the speech to which he is exposed so as to induce from it a latent structure. This latent rule structure is so general that a child can spin out its implications all his life long†¦. The discovery of latent structure is the greatest of the processes involved in language acquisition, and the most difficult to understand† (Brown & Bellugi, 1964, p. 314) Brown collected samples of spontaneous speech from three children, given the pseudonyms Adam, Eve, and Sarah. The corpus of collected data can be found in the Packer Two-Word Utterances 3 CHILDES archive. Eve was visited from age 18m to 26m, Adam from 27m to 42m, Sarah from 27m to 48m. Dan Slobin described the project: â€Å"We paid close attention to the auxiliary system and to word-order patterns, because these had played a central role in Syntactic Structures. We kept track of sentence types—affirmative, negative, and questions—in which use of auxiliaries and word order would vary. Linguistic growth was assessed in terms of things to be added to childish sentences to make them adult-like: the additions of omitted functors (inflections, prepositions, articles, and the like) and transformational operations. We did not categorize utterances in terms of communicative intent—that is, in terms of semantics or speech acts or extended discourse skills—and so we did not look for growth in terms of additions or enrichment of such abilities. Our central concern was with syntax and morphology, with some later interest in prosody. We worried about such questions as whether child grammar was finite state or transformational, and whether syntactic ‘kernels’ were the first sentence forms to appear in child speech† (Slobin, 1988, p. 11). Mean Length of Utterance This simple measure of syntactic complexity was introduced by Roger Brown. Table 7. Rules for calculating mean length of utterance and upper bound (Brown, 1973, p. 54) 1. Start with the second page of the transcription unless that page involves a recitation of some kind. In this latter case start with the first recitation-free stretch. Count the first100 utterances satisfying the following rules. 2. Only fully transcribed utterances are used; none with blanks. Portions of utterances, entered in parentheses to indicate doubtful transcription, are used. 3. Include all exact utterance repetitions (marked with a plus sign in records). Stuttering is marked as repeated efforts at a single word; count the word once in the most complete form produced. In the few cases where a word is produced for emphasis or the like (no, no, no) count each occurrence. 4. Do not count such fillers as mm or oh, but do count no, yeah, and hi. 5. All compound words (two or more free morphemes), proper names, and ritualized reduplications count as single words. Examples: birthday, rackety-boom, choo-choo, quack-quack, night-night, pocketbook, see saw. Justification is that no evidence that the constituent morphemes function as such for these children. 6. Count as one morpheme all irregular pasts of the verb (got, did, went, saw). Justification is that there is no evidence that the child relates these to present forms. 7.  Count as one morpheme all diminutives (doggie, mommie) because these children at least do not seem to use the suffix productively. Diminutives are the standard forms used by the child. 8. Count as separate morphemes all auxiliaries (is, have, will, can, must, would). Also all catenatives: gonna, wanna, hafta. These latter counted as single morphemes rather than as going to or want to because evidence is that they function so for the children. Count as separate morphemes all inflections, for example, possessive {s}, plural {s}, third person singular {s}, regular past {d}, progressive {ing}. 9. The range count follows the above rules but is always calculated for the total Packer Two-Word Utterances 4 transcription rather than for 100 utterances. The title of Brown’s 1973 book, summarizing of a decade of research (his own and other people’s), was A First Language: The Early Stages. A follow-up was planned, describing the â€Å"later† stages, but never written. What is this book about? â€Å"It is about knowledge; knowledge concerning grammar and the meanings coded by grammar†¦. The book primarily presents evidence that knowledge of the kind described develops in an approximately invariant form in all children, through at different rates. There is also evidence that the primary determinants of the order are the relative semantical and grammatical complexity† (58) Here is an early attempt to write a â€Å"syntactic† grammar of two-word speech, first describing only 89 observed utterances (Table 4), then going â€Å"beyond the obtained sentences to the syntactic classes they suggest (Table 5) (Brown & Fraser, 1964, pp. 59, 61): Packer Two-Word Utterances 5 Brown’s Two Main Findings Two main findings are described in A First Language. 1. The â€Å"Semantic Look† of Stage I Speech First, that the organization of early word-combinations cannot be described in purely syntactic terms. Brown and his coworkers quickly had to change direction. Syntactic descriptions didn’t suffice. That’s to say, Stage I constructions couldn’t be satisfactorily explained either as â€Å"telegraphic† speech, or in terms of â€Å"pivot-open† grammar. Telegraphic Speech One of the first ways of characterizing 2-word utterances was to say that they omitted â€Å"function words,† such as articles, auxiliary verbs, inflexions, prepositions, and the copula (is). The words that are spoken tend to be nouns, verbs, and adjectives, and their order tends to resemble the order in what one presumes the adult sentence would be. These characteristics make early utterances sound like telegrams. But inflections are omitted too, and these are free in telegrams. And a few functors such as more, no, you and off are found. More important problems are that this description uses adult categories. And it doesn’t explain the productive character of children’s two-word utterances. Pivot-Open grammars Martin Braine suggested that children have simple rules they use to generate two-word utterances. Each pair of words selects one from a small set of words—called â€Å"pivots†Ã¢â‚¬â€that occur in many utterances, and always in a fixed position (either the first word, or the second). For example, â€Å"Allgone† is a first-position pivot: allgone egg, allgone shoe, but not shoe allgone. A second-position pivot â€Å"off†: shirt off, water off, etc. The choice of the second word is more â€Å"open. † Packer Two-Word Utterances 6 But â€Å"the rules simply do not fit the evidence; pivot words do occur in isolation, pivots occur in combination with one another, sentences longer than two-words are fairly common in I, and there is distributional evidence which indicates that more than two word-classes exist† (Brown, 1973, p. 110). Brown and his colleagues noted that adults â€Å"expand† children’s utterances. These expansions don’t seem effective in teaching the child anything new (Cazden, 1965). But they do provide important clues to the researcher. If one assumes that adult expansions are generally accurate interpretations of the child’s utterance, then pivot-open grammars are inadequate because they underestimate the child’s knowledge. (Both would simply be described as O + O. ) For example, Lois Bloom showed that when one attended to context the utterance mommy sock was used by her child in two different ways. The first could be glossed as â€Å"It’s mommy’s sock,† while the second could be glossed â€Å"Mommy is putting on your sock. † A pivot-open grammar would not be able to distinguish these two. From Non-Semantic (Lean) Grammars to Semantic (Rich) Grammars So Brown and his co-workers started instead to describe two-word utterances in semantic terms. They employed a process that Lois Bloom called â€Å"rich interpretation†: using all the contextual information available to infer what the child meant by an utterance. As Lois Bloom said, â€Å"evaluation of the children’s language began with the basic assumption that it was possible to reach the semantics of children’s sentences by considering nonlinguistic information from context and behavior in relation to linguistic performance. This is not to say that the inherent ‘meaning’ or the child’s actual semantic intent was obtainable for any given utterance. The semantic interpretation inherent in an utterance is part of the intuition of the child and cannot be ‘known’ with authority. The only claim that could be made was the evaluation of an utterance in relation to the context in which it occurred provided more information for analyzing intrinsic structure than would a simple distributional analysis of the recorded corpus† (Bloom, 1970, p. 10). The result was the identification of a small set of basic semantic relations that the children’s utterances seems to be expressing. The eight most common of these are summarized in the following table (cf. Brown, p.193-197): â€Å"Major Meanings at Stage I† Two-Word Utterance mommy come; daddy sit drive car; eat grape mommy sock; baby book go park; sit chair cup table; toy floor my teddy; mommy dress Semantic relation expressed agent + action action + object agent + object action + location entity + location possessor + possession Packer Two-Word Utterances 7 box shiny; crayon big dat money; dis telephone entity + attribute demonstrative + entity It seems that children when they first combine words talk about objects: pointing them out, naming them, indicating their location, what they are  like, who owns them, and who is doing things to them. They also talk about actions performed by people, and the objects and locations of these actions. Brown suggested that these are the concepts the child has just finished differentiating in the sensorimotor stage. This kind of semantic characterization of children’s speech continues in current research. For example, the following table is redrawn from Golinkoff & Hirsh-Pasek, (1999, p. 151. ) The terminology differs a little, and Recurrence and Disappearance have been added (or at least were not in Brown’s â€Å"top eight†), but other than this the picture is the same. Two-Word Utterance Mommy sock Probable meaning expressed Possessor-possessed or Agent (acting on) an object Recurrence Disappearance or Nonexistence Action on object Agent doing an action Object at location Object and property Naming Possible gloss â€Å"That’s Mommy’s sock† or â€Å"Mommy, put on my sock† â€Å"I want more juice† â€Å"The outside is allgone† (said after front door is closed) â€Å"(Dad) is throwing the toy chicken† â€Å"The car is going† â€Å"The sweater is on the chair† â€Å"The dog is little† â€Å"That is Susan† or â€Å"Her name is Susan†. More juice! Allgone outside Throw chicken Car go Sweater chair Little dog That Susan What Grammar to Write? How to represent the knowledge that underlies children’s utterances viewed in these semantic terms? What kind of grammar can one write? Brown (1973) reviewed several possibilities are concluded that â€Å"No fully explicit grammar proves to be possible† (p. 244). Bloom wrote essentially syntactic grammars, which however included information necessary to give an appropriate semantic interpretation. Schlesinger (assigned reading) wrote a semantic grammar. Antinucci & Paresi (optional reading) wrote a grammar that included some pragmatic information too. The following is a grammar for one of the three children Bloom studied: it â€Å"consists of (1) the phrase structure, (2) lexico feature rules, and (3) transformations (Bloom, 1970, pp. 67-68): Packer Two-Word Utterances 8 Packer Two-Word Utterances 9 Criticism of Interpretive Analysis An interesting criticism of these semantic analyses was made by Howe in 1976. Howe noticed a lack of consistency across semantic categorization of two-word utterances by Bloom, Slobin, Schlesinger and Brown, and suggested that the identification of semantic relations actually tells us more about adult interpretation of children’s speech that is does about what the child has in mind. â€Å"Overall, the existence of contradictions between the categories presented in Table 1, the fact that some of the categories are not always mutually exclusive and the fact that it is hard to demonstrate that some of the so-called ‘semantic’ distinctions are more than syntactic alternatives for expressing the same meaning, make it unlikely that Bloom, Brown, Schlesinger and Slobin have produced an adequate categorization of the meanings common to the speech of children at the beginnings of word combination or indeed of adults†¦. [A]ll four writers tacitly assumed that the two-word utterances of young children always express a meaning adults might express using these words and hence their aim was to specify which of the meanings adults might express occur in the first word combinations† (Howe, 1976, p. 34). Howe asserted that (as she later put it) â€Å"there was no evidence that children at the beginning of word combination recognize a world containing agents, locations, and so on† (Howe, 1981, p. 443). It is interesting to read the next rounds of this debate: Bloom, Capatides, & Tackeff (1981), Golinkoff (1981), and Howe’s reply (1981). Bloom is witheringly derisive (and seems to miss the point of Howe’s article), Golinkoff is more constructive. Howe accepts Golinkoff’s suggestion that non-linguistic data will show us how a child understands their situation, and she concludes that so far the research shows â€Å"that children do not discover that language encodes roles [played in actions and states of affairs, as distinct from entities involved in actions and states of affairs], until some time after their first word combinations† (451). But I  think there’s a larger point here that I’ll explore in class. Brown’s conclusions about Stage I Brown drew the following conclusions about Stage I: â€Å"The Stage I child operates as if all major sentence constituents were optional, and this does not seem to be because of some absolute ceiling on sentence complexity. In Stage II and after we shall see that he operates, often for long periods, as if grammatical morphemes were optional. Furthermore, the child’s omissions are by no means limited to the relatively lawful omissions which also occur in adult speech. He often leaves out what is linguistically obligatory. This suggests to me that the child expects always to be understood if he produces any appropriate words at all. And in fact we find that he would usually be right in this expectation as long as he speaks at home, in familiar surroundings, and to family members who know his history and inclinations. Stage I speech may then be said to be well adapted to its communicative purpose, well adapted but narrowly adapted. In new surroundings and with less familiar addresses it would  Packer Two-Word Utterances 10 often fail. This suggests that a major dimension of linguistic development is learning to express always and automatically certain things (agent, action, number, tense, and so on) even though these meanings may be in many particular contexts quite redundant. The child who is going to move out into the world, as children do, must learn to make his speech broadly and flexible adaptive† (Brown, 1973, p. 244-245). 2. The Acquisition of Grammatical Morphemes in Stage II  The second major finding that Brown reported in A First Language was that â€Å"a set of little words and inflections begins to appear: a few prepositions, especially in and on, an occasional article, an occasional copula am, is, or are, the plural and possessive inflections on the noun, the progressive, past, and third person present indicative inflections on the verb. All these, like an intricate sort of ivy, begin to grow up between and upon the major construction blocks, the nouns and the verbs, to which Stage I is largely limited† (Brown, 1973, p.  249). Brown found that the 14 of these grammatical morphemes of English that he selected for detailed study were acquired in a fixed and universal order. These are the grammatical morphemes we discussed in an earlier class: affixes like –s, -ed, {PAST}, and small function words like on, in, the. We’ve already noted that these morphemes are omitted from the first word-combinations. Brown studied the way they are gradually added to a child’s speech. This takes place in what he called Stage II. The child begins to explicitly mark notions such as number, specificity, tense, aspect, mood, using the inflections or unbound morphemes. Of course, Brown was studying only three children, but the finding of invariant order has stood up when larger numbers of children have been studied. For example, de Villiers and de Villiers (1973) replicated his finding with a sample of twenty-one children. Brown offered evidence that the order of their acquisition was determined by their linguistic complexity. (That’s to say, the number of features each of them encoded.) (Though he noted too that children differ greatly in their rate of acquisition of these morphemes. ) Order 1. 2/3. 4. 5. 6. 7. 8. 9. 10. Morpheme present progressive prepositions plural irregular past tense possessive copula uncontractible articles regular past tense third-person present tense regular Example singing; playing in the cup; on the floor books; dolls broke; went Mommy’s chair; Susie’s teddy This is my book The teddy; A table walked; played he climbs; Mommy cooks Packer Two-Word Utterances 11 11. 12. 13. 14.  third-person present tense irregular auxiliary uncontractible copula contractible auxiliary contractible John has three cookies She was going to school; Do you like me? I’m happy; you are special Mommy’s going shopping Brown examined each utterance is see whether it required any of these morphemes to make it fully grammatical by adult standards, attending to both linguistic and nonlinguistic context. E. g. , when the child points to a book and says that book, Brown inferred that there should have been a copula (‘s or is) and an article (a). Then he checked how many of these obligatory positions for each morpheme were actually filled with the appropriate morphemes at each age. Acquisition—defined as the age at which a morpheme is supplied in 90 percent of its obligatory positions—was remarkably constant across Brown’s three subjects. Why did Brown study these morphemes? Presumably because they are at first omitted. But more importantly, he was trying to test the hypothesis that children are taught grammar by adults. And Brown found that frequency of exposure (in adult speech) was not a predictor. For example, adults used articles more frequently than prepositions, but children acquired these in the opposite order. Brown suggested that linguistic complexity does predict acquisition. The morphemes differ in both semantic complexity (the number of semantic features encoded) and syntactic complexity (the number of rules each requires). For example, the copula verb encodes both number and temporality. These two types of complexity are highly correlated, so they cannot be teased apart, but in either case they predict order of acquisition. The other important change that occurs in Stage II is that, as utterances grow in complexity, the child begins to combine two or more of the basic semantic relations from Stage I: Adam hit ball = agent + action + object = agent + action, plus action + object The Other Stages of Language Acquisition Each of the five stages that Brown distinguished is named for the linguistic process that is the major new development occurring in that stage (â€Å"or for an exceptionally elaborate development of a process at that stage† p. 59). Thus we have: Packer Two-Word Utterances 12. Stage I. Semantic Roles & Syntactic Relations. MLU: 1. 0 – 2. 0 agent, patient, instrument, locative etc. expressed (in simple sentences) by linear order, syntactic relations, prepositions or postpositions. Stage II. Grammatical Morphemes & the Modulation of Meaning. MLU: 2. 0 – 2. 5 Stage III. Modalities of the Simple Sentence. MLU: 2. 5 Next the child forms transformations of simple declarative sentences: yes-no interrogatives, question request, negation, imperative. During the earlier stages children use intonation to mark different sentence modalities. Now they begin to use morphosemantic devices to mark negatives, questions, and imperatives. Stage IV. Embedding of Sentences One simple sentence will now become used as a grammatical constituent or in a semantic role within another sentence. Stage V. Coordination of Simple Sentences & Propositional Relations Sentences are linked together with connector words. Individual Differences Brown also noted some individual differences among Adam, Eve, and Sarah. Two of the children combined V with N, and also used N for possession: eat meat, throw ball, mommy sock. But the child third combined V (or objects of possession) with pronouns: eat it, do this one, my teddy. These two strategies were found by other researchers too. Catherine Nelson called them pronominal & nominal strategies (they have also been called â€Å"holistic & analytic†; â€Å"expressive & referential†), and noted that they could be seen in one-word utterances also: some children tend to produce single-word utterances that are nouns, other children tend to use social or personal words such as hi, bye, and please. Subsequent research has explored the connections between these strategies and later development, cognitive style, and input differences (cf. Shore, 1995. Individual differences in language development, Sage). However, these strategies converge over time. By MLU=2. 5, sentence subjects (agents) are typically pronominal, and predicate objects (patients) are typically nominal. Packer Two-Word Utterances 13 Directions After Brown By the mid-1970s grammar-writing was dying out. Incorrect predictions had discouraged researchers, as had the problem of indeterminacy: the fact that more than one grammar could be written. Interest was growing in other considerations: in the role of semantics; in cognitive precursors to syntax, and to language in general; in mother-child interaction; and in the pragmatic uses to which early speech is put. In the view of some people, linguistic structures and operations became neglected. 1. How Does the Child go from Semantics to Syntax? We’ve seen that Brown’s research found that the grammar of children’s early word combinations was better described in semantic than in syntactic terms. If this is so, how does a child make the transition from a semantic grammar to the adult grammar? Researchers continue to argue about this. Steven Pinker (1984, 1987) suggests that children use semantics to enter the syntactic system of their language. In simple â€Å"basic sentences† the correspondence between things and names maps onto the syntactic category of nouns. Words for physical attributes and changes of state map onto verbs. Semantic agents are almost always the grammatical subjects of sentences. This semantic-syntactic correspondence in early utterances provides a key to abstract syntactic categories of grammar. Paul Bloom has argued that children actually are using syntactic categories from the start, and he cites as evidence for this the fact that children will they place adjectives before nouns but not pronouns: big dog but not: * small she Some linguists have offered a syntactic description of Stage I utterances. They argue that at this stage children merely have a lexicon and a limited set of phrase structure rules in deep-structure. They lack functional categories such as INFL (inflectionals) and COMP (complementizers). No transformations exist at this stage: instead, elements of the deep structure are assigned thematic (i. e. semantic) roles to yield the surfacestructure. And they have proposed that the lack of grammatical subjects in Stage I utterances reflects the default setting of a â€Å"null-subject parameter. † (Since in languages like Italian and Spanish a subject is optional. ) Lois Bloom (1990b) has suggested that children simply have a more limited processing capacity at this age. Sentence subjects are often provided by context, and so can be safely omitted. Dan Slobin has proposed that â€Å"children create grammars in which clearly identifiable surface forms map onto basic semantic categories† (1988, p. 15). Packer Two-Word Utterances 14 For example, locative prepositions—in, on, under—are omitted in early child speech. They are used earlier in languages when they are encoded more saliently—as noun suffixes or as postpositions following nouns. At the same time, there is a common order of emergence across languages: simple topological notions of proximity, containment and support (in, on, under, next to), with locative relations embodying notions of perspective (back, front) always later. Slobin infers that â€Å"conceptual development provides the content for linguistic expression, while linguistic discovery procedures are necessary for working out the mapping of content according to conventions of particular languages† (p. 15). Slobin has looked carefully at the English grammatical morphemes—and their equivalents in other languages—to see how they are used before they are completely acquired (by Brown’s 90% criterion). He finds that children generally use the morphemes systematically, though their use is still â€Å"incomplete† by adult standards. For example, a Russian child applied the accusative inflection only to nouns that â€Å"were objects of direct, physical manipulation, such as ‘give,’ ‘carry,’ ‘put,’ and ‘throw,’ omitting the accusative for less manipulative verbs such as ‘read’ and ‘see. ’† Children will â€Å"organize systems of pronouns and case inflections; but, to begin with, children will organize these various forms to express particular, child-oriented speech functions† (p. 18). They are using the resources of the adult language to mark distinctions that are salient to them. Slobin has also proposed some â€Å"universal language-learning principles. † These are an attempt to explain observed cross-language regularities in order of acquisition. â€Å"According to Slobin, the child has certain concepts, based on cognitive growth, that are expressed through the language system. Using certain principles of acquisition, the child scans the language code to discover the means of comprehension and production† (Owens, 2001, p. 214-215). 1. Pay attention to the ends of words 2. Phonological forms of words can be systematically modified 3. Pay attention to the order of words and morphemes 4. Avoid interruption and rearrangement of linguistic units 5. Underlying semantic relations should be marked overtly and clearly 6. Avoid exceptions 7. The use of grammatical markers should make semantic sense Knowledge of Verb syntax Lois Bloom asserts that learning the argument structure of verbs, and the syntactic differences for different thematic relations is the foundation for acquiring a grammar. Verbs play a central role in further multiword utterances. Opinions differ, however, on how knowledge of verb syntax is acquired. Bloom suggests that the first verbs are those that name actions (do, make, push, eat). Nouns and pronouns take thematic roles (agent, object) in relation to these actions. Bloom says that this implies that children’s â€Å"theories† of objects, space, and causation are important here. Packer Two-Word Utterances 15 A few all-purpose verbs—â€Å"pro-verbs†Ã¢â‚¬â€are used for most early sentences. E. g. , do, go. With these, verb argument structures, verb inflections, and Wh-questions are learned. Subsequently, the child adds the syntax for negation, noun- and verb-inflection, and questions. And then moves on to embedded verb phrases (â€Å"drink [Mommy juice]†) 2. From Semantics to Semantics Language involves a great deal of categorization. â€Å"The forms of language are themselves categories, and these forms are linked to a vast network of categorical distinctions in meaning and discourse function† (Bowerman, 1988, p. 28-29).