Sunday, May 17, 2015

Time to Practice – Week Three

Complete both Part A and Part B below.

Part A



1.     What does the critical value represent? (2 points) The critical value represents a value an individual would assume the test at hand to produce if the null hypothesis were true. It is the statistic a person believes to find.

2.     Given the following information, would your decision be to reject or fail to reject the null hypothesis? Setting the level of significance at .05 for decision making, provide an explanation for your conclusion. (3 points)

a.     The null hypothesis that there is no relationship between the type of music a person listens to and his crime rate (p < .05).  Null hypothesis is rejected as p value is less than .05
b.     The null hypothesis that there is no relationship between the amount of coffee consumption and GPA (p = .62).  Since p=.62, which is more than .05 or greater we accept the null hypothesis.
c.     The null hypothesis that there is no relationship between the number of hours worked and level of job satisfaction (p = .51). since p=.51 greater than .05 accept null hypothesis.

3.     Why is it harder to find a significant outcome (all other things being equal) when the research hypothesis is being tested at the .01 rather than the .05 level of significance? (2 points) When the test is done at the .01 rather than .05 it produces a much small value set while .05 produces a larger one. This leads to the contradictory data which is quite larder in the research hypothesis and more likely.




Part B


Complete the following questions. Be specific and provide examples when relevant.

Cite any sources consistent with APA guidelines.

Question
Answer
What is a research question that you would like to answer? Write the null and research hypotheses. Would you use a one- or two-tailed test? Why? (3 points)
If the Health department is tasked with finding out the rate of lung cancer connected with smoking in the past year is it comparable to average rate past 50 years.
Null hypothesis: No difference in last year and last 50 years. Research hypothesis: there is a difference in last year and last 50 years.
Using a two-tailed test because of the research hypothesis would show that it was not equal
What do we mean when we say that a statistical result is significant? What is the difference between a statistically significant and a meaningful result? Why is statistical significance important?  (4 points)
Significant means that there is a rate of certain probability in something. Meaningful results state that the results are valid and statically significant which means a person rejects the null hypothesis. With there being some probable difference between the results we can conclude the null hypothesis is not acceptable and should be rejected.



From Salkind (2011). Copyright © 2012 SAGE. All Rights Reserved.


Saturday, May 9, 2015

Reliability and Validity Matrix


For each of the tests of reliability and validity listed on the matrix, prepare a 50- to 70-word description of the test’s application. Describe what conditions these reliability types would be used for, as well as when they would be inappropriate. Then, for each test, prepare a 50- to 70-word description of the strengths and a 50- to 70-word description of the weaknesses.

Test of reliability
Application and appropriateness
Advantages
Disadvantages
Internal consistency

In internal consistency deals with assessing consistency of internal items or internal consistency of the items on a test.  This is used in order to estimate the reliability of items that are on the test without the need to develop alternate or additional forms of a test or having to give the test more than one time. Internal consistency employs a single measurement to estimate a test’s reliability. 
One of the greatest advantages comes from only needing to administer the test one time and thus it provides a cost efficient and effective nature to the test taking process. Another advantage comes from internal consistency, which can be gained through a wide measurement of tests and through a variety of items.  
One disadvantage is that high reliabilities with this method may actually be considered a weakness as it can indicate a redundancy in the test items and measures used. Another disadvantage comes from the results not being taken from the theory, which results in all variables being considered. The results are never perfect but rather have to be theorized to try to perfect the results.
Test or retest


With the use of this test a developer provides the test twice to an individual on different occasions. The developer compares the two scores in order to assure the testers haven’t changed from one test to the next. This method allows a way to estimate reliability, as there is a higher correlation between testers taking tests within shorter amounts of time between each test.
The advantage of this method is that it produces a lower score when it is compared with other methods. The time frame being shorter between first test and retest provide correlations between timeframes and lower scores being produced. Another advantage is that the method uses a single score or rater code.
Some disadvantages to the method is that it can be prone to weaknesses like from carryover effects attributing to or causing errors that are found in test scores. Timeframes can also affect scores produced by testers on the retake test. The method can also prove to be more costly since it requires the test be given multiple times and it can lack in reliability.
Parallel and alternate forms


Parallel test exist when all the additional or alternate forms are equal in means and variances of the observed test scores. The theory behind it is that means on parallel forms correlate equally to the true score of the test. Alternate forms are a method in which different test versions have been created to parallel the original test.
Advantages of these tests include that it can minimize effects that memory of content may have on administering previous forms of the test.  The tests may also provide stable scores and information in certain circumstances when measuring certain constructs.  Another advantages comes from being able to estimate reliability without having to develop another form of the test.
Disadvantages come from having to develop alternate forms of the test, which can be expensive as well as time consuming. Errors may result in variance or item sampling when trying to compute the alternate or parallel form of the reliability coefficient. Finally, the person taking the test may have performance issues, which are affected by a specific for of the test, done to the items included on that test.
Test of validity
Application and appropriateness
Strengths
Weaknesses
Content validity


Content validity is concerned with scrutinizing the content of the test as well as the extent to which the test measures represents all the facets for a given construct. A judgment is made of how adequately the test is able to sample behaviors that represent the universe of behavior in which the test was created for.
Advantages of the method involve defining as well as finding domain of items in which a creator of the test wants to measure. It helps to increase a test’s validity and leads to content validity. Items on the test go with things wanting to be measured without deviating from items that want to be measured.
The disadvantages of this method are that can require experts to design, develop, and evaluate the test and scores. This makes the test both expensive as well as time consuming.  Furthermore, the test may have a need to cover a variety of items and information that can be long for either administering or taking the test.
Criterion related


Criterion related is used in order to demonstrate accuracy of a procedure or measure by comparing the procedure with another one to demonstrate it to be valid. It is used as a judgment of the adequacy of the test to basically predict or infer a person’s score on a given subject.
One advantage of the method is that involves use of two estimators to demonstrate validity of a test that has been given. This method works for academic use in being able to predict scores. Additionally it can work well in the determination of how certain things like traits develop overtime.
Disadvantages associated with the method include accuracy. Individuals change overtime which can lead to problems with accuracy or reliability with the tests. Another disadvantage is in the change to academics itself, individuals learn one thing and it is changed on the test or it needs to be changed on the test making it costly to do so.
Construct


Construct deals with a test or an experiment being able to measure what it claims to do.  It refers to the operational definition of a variable actually reflecting the theoretical meaning of a certain concept.  This method requires judgment about appropriateness of the scores drawn from the inferences in a person’s standings. 
One advantages of this method include that domain of an item or the behavior wanting to be measured is obtained. The domain behavior is kept in mind as the items on the experiment or test are reviewed so all items can show a relationship with behaviors wishing to be measured.
Disadvantages of the method require experts in the areas of the test or experiments to help with the tests. Additionally experts are also needed in the use of the experiments and evaluation of tests that makes the test more time consuming as well as being more costly to create, perform, as well as evaluate. Finally, the mere development of the test is not easy either.


Monday, May 4, 2015

Basic Concepts in Statistics

Differentiate between descriptive and inferential statistics. What information do they provide? What are their similarities and differences? Your answer should be 250 to 400 words.

Descriptive statistics are values that describe the characteristics of a sample or a population. Descriptive statistics allows a large amount of information or data to be used in order to come up with a summary of the data (Salkind, 2014). 
. For instance if you had a list of students at a school from the same grade and listed all their grades in differing subjects you could use descriptive statistics in order to find the average or mode of the kids grades. Descriptive statistics is able to take either a large sample or a population and turn the list of information, data set, into a summary that researchers can then use in different capacities such as predicting the grades of students across an age group.  If the researcher wanted to see what subject children excel more in then through the use of the grades and the differing subjects they would be able to find that information. Inferential statistics is different as it is the tools that are used in order to infer the results based on a sample to the population (Salkind, 2014). Inferential sometimes follows descriptive statistics as the next step in the process taking the small group that may have been used and applying the information to a larger group or population.  The inferential statistics allow researchers to make a kind of guess into how the summary that was created may apply to a larger population.  If researchers took a sample of a few different students from several schools in order to find grades in subjects they could then use the results to infer what the whole population may look like.


What is a population? What is a sample? How are they similar and how are they different? When would you use one or the other? Your answer should be 250 to 400 words.


A population according to Salkind (2014).  Is all the possible subjects or cases of interest.  So if a person wanted to know how good a soccer team was then they would use all individuals on the soccer team as the population when doing calculations.  While sample is a subset of a population (Salkind, 2014). It is much like its name describes and only a small portion of the total population. So in the soccer team you would take 10 players and this would be the sample. Both are representatives of the data that a person is trying to produce with one entailing all the subjects involved and the other only being made up of a portion.  When a population is relatively small such as the example of the soccer team then it is possible to use the entire population in the calculations being done. However when the population is larger such as looking at teen drug use then the population would include a size so big that it would be relatively impossible to look at all teens in the world. It would take too much time any money in order to do this. In this case a sample is pulled in order to represent the entire population while still getting the insight that a behavioral scientist is looking for. That way the scientist is able to pull a relatively small amount in comparison to the entire globe and is able to make inferences on who the results apply to the entire population of teens.





Salkind, Neil, J.(2014). Statistics for People Who Think They Hate Statistics. 5th Edition. Sage Publications.

Sunday, April 5, 2015

Multicultural Project Planning

Post War Iraq
Introduction
            Multicultural project planning is a procedure of planning that gives consideration to all the cultures at the time the project is created. The project that includes a variation of diverse customs, concerning growth or conduct of the followers is referred as multicultural project. Although all participants in the project come from the same country, the project manager (PM) will still be dealing with several cultures and their outlooks and conducts (Rothman, 2001). The cultural dissimilarities lead the researchers to attempt in identifying several plans that would be appropriate to the project. The humanitarians look for the promotion of human welfare. When employed into a humanitarian organization, it is requested that such organization is extended into Iraq to help in the nation’s innovation struggle. Before the start of the project, there are three subjects that need to be examined. It is expected that part of the planning procedures is the existence of different ethnocentric tests. It is imperative for the researcher to be knowledgeable enough on the possible kinds of questions that will be given.
Three Topics for Better Understanding
I like to understand more about the facts of the battle, in what way people are affected by it and who are they, and also what is necessary from the organization to assist the nation’s renovation effort before starting the project. Learning the details about the war is the first that I like to know more. With this, I like to know about the reasons of the war and what really happened including he causes and effects. Knowing all these will aid me to determine the changes that exist in the country and the extent to which the areas were destroyed and eventually affect the current living conditions of the people. Besides, I like to make investigations on who were and how were the persons affected by the battle. I also like to examine the changes in terms of the behaviors and emotions of the people who were impacted by the incident. It is interesting for me to be aware on how these people adjusted to the situations, to think of those that the organization will provide. Furthermore, I like to acquaint myself with those who were affected like their ethnic background, culture, and languages used. This will give data so the organization will become efficient in growing it. Finally, I like to know the things which are necessary for the organization to help the country’s renovation. I need to understand more the aim and welfares of the growing organization in Iraq before the multicultural project planning be started. This serves as guide that is essential in operating the organization and addressing the people’s necessities. The organization’s primary aims are to give relief, aid to renovate, and help in improving. The mentioned topics would lead me to understand how the aims will be realized.
Ethnocentric Challenges during Planning
The word, “ethnocentric,” refers to the evaluation of the people and their cultures, according to the standards set by the culture (Merriam-Webster, 2013). Ethnocentric encounters that may stand up when organizing the project comprise bias views on the most essential things required for the persons of varied cultures or backgrounds for language obstacles, assistance, concerning what things are to be comprehended and how to do it, and also the social struggles in an attempt to interrelate or learn information with people as the source. Prejudice views can be made regarding the most essential things required for the people of varied cultural backgrounds. For a particular culture, certain things may not be significant to me but are valued by them. This is a challenging part when attempting to determine the expectations from this project like what the humanitarian organization provides. For an instance, food necessity might not be significant to the other individuals unlike to oneself. Individuals may like to eat particular substance or make their personal foods depending on their religious beliefs. Ethnocentric challenges can also be brought by language barriers. In a nation, the people may have the ability to express through varied language and they also understand phrases differently due to diverse culture(s). This is somewhat challenging since communication is significant and is very essential to begin and complete the project that is growing the organization to Iraq. Ineffective communication will have negative outcome. The social encounters belong to language barrier issues. They exist during the interaction of varied cultures. When the war is over, most of the individuals may have no interest to share with the researchers their desire for a living based on their own culture. Conflicts can be caused by social challenges including the cultural standards.
Types of Questions Researcher should ask
It is necessary that the researcher will be asking about the languages and cultures of Iraq; distinguish those what the human organization can give and how to realize the organization’s expansion in Iraq. In Iraq, there are different languages used like Akkadian, Sumerian, Aramaic (both ancient and modern), Hurrian (ancient), colloquial Iraqi Arabic, Iraqi Turkman (modern), and Kurdish (Abdi, Mulderig, Rouhbakshan, Ashiroy, & Alexander, 2008). For an instance, as shown by the video of “Post War Conditions”, translation was required to get information from the people in Iraq to determine what their needs are as part of their rebuilding effort. Translators should be hired so that the information received from the people will be fully understood including their necessities. Furthermore, a boy made mention that there is a bad supply of water. The humanitarian organization must supply this need for it is one of its primary priorities to render the basic needs of the people like power, communication, and water besides, it must also uphold the welfare of human beings (Barnett & Webber, 2003). It is important for the researcher to know about the ways which the project can be realized into Iraq. Questions like these pay attention on security, laws and identification of the proper area in Iraq intended for the organization. For an instance, the researcher likes to get information about the possible expenses of the project including its safety. Determining the most suitable areas in Iraq for the project is what the researchers should do for it is helpful in the nation’s rebuilding effort. Such information is very beneficial regarding the area where the organization shall be expanded.
Conclusion
Multicultural project planning is a procedure of planning that gives consideration to all the cultures at the time the project is created. The project that includes a variation of diverse customs, concerning growth or conduct of the followers is referred as multicultural project. I like to understand more about the facts of the battle, in what way people are affected by it and who are they, and also what is necessary from the organization to assist the nation’s renovation effort before starting the project. The mentioned topics would lead me to understand how the aims will be realized. Ethnocentric encounters that may stand up when organizing the project comprise bias views on the most essential things required for the persons of varied cultures or backgrounds for language obstacles, assistance, concerning what things are to be comprehended and how to do it, and also the social struggles in an attempt to interrelate or learn information with people as the source. It is necessary that the researcher will be asking about the languages and cultures of Iraq; distinguish those what the human organization can give and how to realize the organization’s expansion in Iraq. Such information is very beneficial regarding the area where the organization shall be expanded.
  
References
Abdi, K., Mulderig, M., Rouhbakhshan, A. A., Ashirov, A., & Alexander, C. (2008).
Books. Anthropology Of The Middle East3(1), 105-114.
Barnett, J., Eggleston, B., & Webber, M. (2003). Peace and development in post-war iraq. 
Middle East Policy, 10(3), 22-32. Retrieved from http://search.proquest.com/docview/203661949?accountid=458
Meriam-Webster. (2013). Ethnocentric.
            Retrieved            http://www.merriam-webster.com/dictionary/ethnocentric
Rothman, Johanna. (2001). Managing Multicultural Projects with Complementary Practices.
            Retrieved from

Thursday, March 26, 2015

Stanley Milgram

In the early 1960s Stanley Milgram began an experiment that would change the way that people viewed obedience to authority. When most people are asked if they would harm a person if ordered to by an authority they respond with a strong no. The experiment done by Milgram set to answer this question in order to better understand how authority and influence the obedience of those under command. This paper is going to look at the Milgram research and experiment on obedience taking a look at the situational variables that make obedience to authority more likely. The paper is going to present a summary of the study, how it was conducted, an explanation of the results, an explanation of the concept of situationism as it applies to the study, and answer some questions such as if the results would differ given different cultures or ethnic groups used as participants in the study. 

Summary of Study
In the early 1960s Milgram after hearing about the WWII trial of Adolph Eichmann who testified that he was just following orders when he helped to kill millions of Jews, became interested in the idea of following orders of authority (Elms, 2009). Milgram wanted to see how far people would go if ordered by an authority figure and designed an experiment in order to do that. Milgram recruited 40 men through newspaper ads and offered to pay them in exchange for their participation. Milgram’s experiment involved the participants being placed in the role of a teacher who asked questions of a student in another room that they couldn’t see; if the student got the question wrong the teacher was to give the student a shock of varying degrees ranging from 30 volts and increase 15 volts each time the student got a question wrong (Elms, 2009).
In the experiment the participant believed they were delivering a shock to a real person, but in reality the student was part of the experiment and only pretending to be shocked. As the teacher began delivering shocks for wrong answers the student would begin to please to stop. As the teacher reached 300 volts the student would bang on the wall, demand to be released, and would begin to refuse to answer questions (Elms, 2009). At this point teachers would be instructed that silence was to be treated as an incorrect response and to shock the student again; the teacher would receive a series of commands to keep them going in the experiment.

Results and Situationism
After the experiment was completed Milgram surveyed a group of Yale students to find out the thoughts people would have on how far individuals would go to obey authority.  The level of the shock that participants in the experiment were willing to give to students was what was used in order to measure obedience.  The surveyed students predicted that only three percent of the participants would have delivered the maximum shock that was allowed in the study, listed only as XXX.  According to Milgram’s results however, 65% of the teachers in the study delivered the maximum shock to students (Milgram, 1973). The results showed that even though participants may have been distraught, in an agitated state, or angry at having to deliver shocks to individuals they believed they were hurting the participants continued on obeying the orders that were given to them.
The concept of situationism is basically a theory that the behavior of humans is determined by the surroundings circumstances of individuals rather than by personal qualities of the person (Fiske, 2010). In the experiment conducted Milgram concluded that there were a number of situational factors which could account for the higher levels of obedience in individuals.  For instance, having the authority figure be physically present increased compliance to obey, having the experiment sponsored by a trusted academic institution like Yale led participants to think it must be safe, the selection to the teacher or student position seemed random, participants assumed the experimenter was a competent expert, and finally the shocks delivered were painful but not dangerous to the student (Milgram, 1973).
Conducting similar studies in which a rebellious peer was present showed that obedience levels were dramatically reduced and individuals refused orders to continue shocking students or to deliver a maximum shock to the student.  In this Milgram (1973), found that situational circumstances greatly affected people’s behaviors in the experiment and he concluded that “when the destructive effects of their work become patently clear, and individuals are asked to carry out actions incompatible with fundamental standards of morality, relatively few people have the resources needed to resist authority" (p. 77). The results of the experiment as well as the further experiments that were conducted show that there is great influence on situational circumstances.  These situation circumstances impact a person’s behavior causing them to act out of character in response to an authority figure and make cause the individuals to become agents of a destructive process despite not wanting to be.

Additional Questions
In whether or not the study results would have been different if the participants were of a different culture, ethnic, or gender group the author believes that the results probably would have been the same.  If Milgram had used women instead of men he may have seen an increase in discomfort from individuals as the shocks increased and students protested more.  However, the results of the individual continuing the shocks or being influenced by the presence of a rebellious peer would most likely remain unchanged.  This would also most likely be the same given different cultures or ethnic groups.
For the question of if the results of the study are important and relevant to contemporary society the results are.  Jerry Burger, a psychology at Santa Clara University, recreated the experiment in order to determine if the results would be the same as they were in the original experiment.  Burger (2009), concluded that in the new experiment individuals obeyed at the same rate as they had nearly 40 years prior in the original experiment.  The results of the study are important in both cases as it shows the impact of the circumstances on how people behave and obey authority figures.  It applies to today’s society because as Milgram stated though individuals may not agree with the course of actions being taken they are ill equipped to resist authority and will instead obey it.

Conclusion
In the early 1960s Stanley Milgram began an experiment that would change the way that people viewed obedience to authority. The experiment done by Milgram set to better understand how authority and influence the obedience of those under command. Milgram wanted to see how far people would go if ordered by an authority figure and designed an experiment in order to do that. The results of the study showed that even though participants may have been distraught, in an agitated state, or angry at having to deliver shocks to individuals they believed they were hurting the participants continued on obeying the orders that were given to them. In the experiment conducted Milgram concluded that there were a number of situational factors which could account for the higher levels of obedience in individuals.  These situation circumstances impact a person’s behavior causing them to act out of character in response to an authority figure and make cause the individuals to become agents of a destructive process despite not wanting to be. The results of the study are important in both cases as it shows the impact of the circumstances on how people behave and obey authority figures.  It applies to today’s society because as Milgram stated though individuals may not agree with the course of actions being taken they are ill equipped to resist authority and will instead obey it.

References

Monday, March 23, 2015

Zimbardo Research

Zimbardo Research
Introduction
Philip Zimbardo is a professor and a psychologist. He is in charge as leader to the researchers or scientists in the Stanford Prison Experiment. Stanford Prison Experiment was a research that recognized the psychological influences of persons, engaging upright individuals in a wicked place. The worth of the Stanford Prison Experiment can be associated to social psychology. Social psychology is the systematic endeavor to clarify how the beliefs, moods, and manners of persons are affected by the concrete, imaginary, or indirect attendance of other people (Fiske, 2010). The research is applicable in relative to modern world matters. The importance of the researhc is also correlated to humankind, in a totality. Concerns were shaped due to the study, but there are present defenses in place to lessen the probability of ethical worries to exist in the research studies.
Relation to Social Psychology
The end of social psychology is to describe how point of view, outlooks, and conducts of beings can be impacted by other persons. As said by Fiske (2010), social influence does not simply influence trivial behavior. It can produce to widely held view over one’s individual conclusion (Fiske, 2010). The research of the Stanford Prison Experiment connects to social psychology in a vast way. The experiment indicates how persons can be impacted by other people when they are put in a particular condition. In the research, persons were designated as convicts or guards in the prison. The inmates had no control and guards had every authority. Some of the detainees became emotive and astounded by the experimentation because of how the prison guards treat them. The other prisoners became senselessly submissive. Prison guards became powerful and abusive to the power provided by the researchers. They were impacted by the activities of convicts, becoming firmer and more governing, as seen on their performance and position. Social psychology based on Stanford Prison Experiment demonstrates how individuals change, due to others, to suit in or adjust to the present events.
Relevance in Relation to Contemporary World Issues
The research is significant in relative to current world problems because the deeds really exist in the society and in prison. Spoken abuse, abuse of authority, and compulsive thinking of detainees happen often in prisons worldwide. Persons are psychology affected by their respective positions of prison guard and convicts. Frequently, authority obtains power and seems the necessity to be abusive on the power, governing other persons. Right inclines persons to step outside their power to obey the rules, presented by them or other individuals with higher power. Persons are apt to to follow to particular deeds and make changes on how they reflect because of the persons who are powerful than them.
Relation to Humanity
The research is appreciated in relative to civilization since each person ponders and acts in ways particular in a diversity of settings. Each one is unique. If placed under pressure and in unacquainted surroundings or circumstances, persons will transform and attempt to adjust to the incidences. People like fair treatment. Numerous persons wish to be powerful, while the others never care obeying authority out of being respectful. Persons will sort out what is desirable to endure.
Problems and Ethical Concerns
Troubles and moral distresses which the study formed contain informed agreement, provoking fierceness, and safety concerns. The persons did not know about the violent treatment they were to show. Persons were physically and psychologically maltreated in the procedures of the research. Forcefulness was also encouraged. The prison guards were allowed to treat the prisoners however they desired to, which is a big issue. The behavior of the prison guards was altered, due to their high power, and the prisoners, who were volunteers, were physically and mentally impacted. They were not totally protected and were uninformed of what was happening.
Current Safeguards
 Existing precautions in order to lessen the possibility of ethical distresses are informed agreement, showing respect of person’s varieties, and credentials of all investigation studies. Communicated consensus allows every person to know the procedures of the research studies before being part of it. It gives them the chance to think whether to participate on the study or not before they were provided with details. Being respectful on the person’s choice let them decide to join or not in a study. The documentation gives information regarding the study to ensure the absence of any kind of cultural concerns and clarify all the procedures as part of the study.
           
Conclusion
The Stanford Prison Experiment was considered as a research study that recognized the psychological influences of persons, assigning good individuals in an evil dwelling. Such study of Stanford Prison Experiment connects to social psychology in a great way. Social psychology, in the situation of the research, indicated that convicts are impacted by jail guards and vice versa. Some detainees became sensitive, while the others were thoughtlessly submissive. The custodial guards enjoyed power and mistreated the power knowing that they were entrusted of the convicts. The research study is significant in relative to present-day world problems because the deeds are usual in jails and society. The study has been treasured in relative to civilization because all human beings reflect and acts particular ways in a diversity of settings. Complications and moral anxieties which the study formed involve informed consensus, provocative fierceness, and security matters. Recent safety measures in place to decrease the probability of ethical distresses are communicated consensus, giving respect to the person’s decisions, and a documentation of all studies.


References
Fiske, S.T. (2010). Social beings: Core motives in social psychology (2nd ed.). Danvers, MA:

Wiley.