Reference no: EM13682038
1. Provide an argument for the idea that basic research is as important as applied research.
2. An infomercial asserts, " A study proves that Fat-B-Gone works, and it will work for you also." What is wrong with this statement?
3. In a research project intended to gather data on the effects of type of study method on examination performance, subjects are randomly assigned to one of two conditions. In one condition, they study alone, using notes they took during class lectures. In a second condition, subjects study in interactive groups with notes from class lectures. The amount of time spent studying is held constant. All students then take the same exam.
In this study:
a. What is the independent variable?
b. What is the dependent variable?
c. Identify the control and experimental groups.
d. Is the independent variable manipulated, or is it a participant variable?
4. Gerontologists interested in the effects of aging on reaction time have two groups of subjects take a test in which they must indicate as quickly as possible whether a probe word is a member of a previous set of words. One group of subjects is between the ages of 25 and 45, whereas the other group is between the ages of 55 and 75. The time it takes to make the response is measured. In this study:
a. What is the independent variable?
b. What is the dependent variable?
c. Identify the control and experimental groups.
d. Is the independent variable manipulated, or is it a participant variable?
5. Using Stevens's four levels of measurement, give an example of nominal, ordinal, interval, and ratio scales (do NOT use examples from the text or lecture).
6. Stanley Milgram's obedience to authority experiment is one of the most controversial studies in psychology's history. Considering this example as well as others, critique such experiments from an ethical standpoint.
7. Identify the type of measure used in each of the following situations:
a. As you leave a restaurant, you are asked to answer a few questions regarding what you thought about the service.
b. When you join a weight loss group, they ask that you keep a food journal noting everything that you eat each day.
c. As part of a research study you are asked to complete a 30-item anxiety inventory.
d. When you visit your career services office, they give you a test that indicates professions to which you are best suited.
e. While eating in the dining hall one day, you notice that food services have people tallying the number of patrons selecting each entrée.
f. As part of a research study, your professor takes pulse and blood pressure measurements on students before and after completing a class exam.
8. When you arrive for your psychology exam, you are flabbergasted to find that all of the questions are on calculus and not psychology. The next day in class, students complain so much that the professor agrees to give you all a makeup exam the following day. When you arrive at class the next day, you find that, although the questions are different, they are once again on calculus. In this example there should be high reliability of what type? What type(s) of validity is the test lacking? Explain your answers.
9. Discuss the advantages and disadvantages of the following nonexperimental research methods: (a) naturalistic observations, (b) surveys, and (c) correlational studies. If you were asked to use one of these designs in a study next week, which nonexperimental design would you select and why?
10. Discuss examples of when a naturalistic observational study would be the most appropriate design to select.
11. Explain the difference between participant and nonparticipant observation and disguised and undisguised observation.
12. Explain how qualitative research differs from quantitative research.
13. Explain the difference between an interview and a focus group interview.
14. Draw a scatterplot indicating a strong negative relationship between the variables of income and mental illness. Be sure to label the axes correctly.
15. Explain the circumstances when a quasiexperimental design would be preferable to a between-subjects design, but also discuss why an explanatory research method is superior to a predictive method.
16. Compare and contrast:
1. Between-subjects with within-subjects designs
2. Small N designs with large N designs.
3. In what circumstances would you use the within-subjects design and in what circumstances would you use the large N design?
17. You read in a health magazine about a study in which a new therapy technique for depression was examined. A group of depressed individuals volunteered to participate in the study, which lasted 9 months.
There were 50 subjects at the beginning of the study and 29 at the end of 9 months. The researchers claimed that of those who completed the program, 85% improved. What possible confounds can you identify in this study?
18. What are internal validity and external validity? Why are they so important to researchers?
19. One of the best-known longitudinal designs is Lewis Terman's study of giftedness. He began tracking gifted children into adolescence and adulthood in 1925; the study is supposed to conclude in 2020. Explain the unique benefits of such a study, and then explain the problems caused by this type of design.
20. Lay out the design for two between-subjects experiments: (a) an experiment involving an experimental group and a control group, and (b) a factorial design with three independent variables that have 3, 2, and 2 levels, respectively.
21. Calculate the mean, median, and mode for the data set in Exercise 1. Is the distribution normal or skewed? Which measure of central tendency is most appropriate for this distribution? Why?
22. Calculate the range and standard deviation for the following five distributions:
a. 1, 2, 3, 4, 5, 6, 7, 8, 9
b. - 4, - 3, - 2, - 1, 0, 1, 2, 3, 4
c. 10, 20, 30, 40, 50, 60, 70, 80, 90
d. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9
e. 100, 200, 300, 400, 500, 600, 700, 800, 900
23. Suppose that, for a t test, your computed value for t is +3.28. The critical value of t is +2.048. Explain what this means. Do you reject the null hypothesis or not? Now suppose that you have 28 degrees of freedom and are using a two-tailed (nondirectional) test. Draw a simple figure to illustrate the relationship between the critical and the computed values of t for this result.
24. Explain the purpose of a null hypothesis. Why are both a research/alternative hypothesis and a null hypothesis necessary in statistics?
25. To test the hypothesis in Exercise 1, the admissions counselors select a random sample of freshmen and compare their scores on the SAT to those of the population of upperclassmen. They find that the freshmen do in fact have a higher mean SAT score. However, what they are unaware of is that the sample of freshmen was not representative of all freshmen at Brainy University. In fact, the sample overrepresented those with high scores and underrepresented those with low scores. What type of error (Type I or Type II) did the counselors make?
26. What are the appropriate H0 and Ha for each of the following research studies? In addition, note whether the hypothesis test is one- or two-tailed.
a. A study in which researchers want to test whether there is a difference in spatial ability between left- and right-handed people.
b. A study in which researchers want to test whether nurses who work 8-hour shifts deliver higher- quality work than those who work 12-hour shifts.
c. A study in which researchers want to determine whether crate-training puppies is superior to training without a crate.
27. What is the standard error of the difference between means?
28. A college student is interested in whether there is a difference between male and female students in the amount of time spent studying each week. The student gathers information from a random sample of male and female students on campus. Amount of time spent studying is normally distributed. The data follow.
a. What statistical test should be used to analyze these data?
b. Identify H0 and Ha for this study.
c. Conduct the appropriate analysis.
d. Should H0 be rejected? What should the researcher conclude?
e. If significant, compute the effect size and interpret.
f. If significant, draw a graph representing the data.
29. A researcher computed the F ratio for a four-group experiment. The computed F is 4.86. The degrees of freedom are 3 for the numerator and 16 for the denominator.
1 Is the computed value of F significant at p < .05? Explain.
2 Is it significant at p < .01? Explain
30. Explain the difference between a t test for independent groups and a t test for matched groups.
31. What are the assumptions of a correlated groups t test?
32. What measure of effect size is used for a correlated-groups t test?
33. The student in Question 5 from Module 18 decides to conduct the same study using a within-subjects design in order to control for differences in cognitive ability. He selects a random sample of participants and has them study different material of equal difficulty in both the music and no music conditions. The data appear below. As before, they are measured on an interval ratio scale and are normally distributed.
a. What statistical test should be used to analyze these data?
b. Identify H0 and Ha for this study.
c. Conduct the appropriate analysis.
d. Should H0 be rejected? What should the researcher conclude?
e. If significant, compute the effect size and interpret.
f. If significant, draw a graph representing the data.
34. Explain how you would show each of the following in a report:
1 The results of a t test with 38 degrees of freedom, where the obtained value of t was 1.38, and the significance level was p < .20.
2 The proper placement of a figure within the text.
3 The proper placement of a table within the text.
35. How can internal and external validity be increased in an experiment?
36. Briefly describe the type of information that should be in an introduction.