Q&A Hero

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.As part of a small side project, John wants to know if fathers monitor daughters more than sons.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.An undergraduate working with John is doing an honors thesis using some of the data that John collected. She wants to know if there is a difference in the amount of parental monitoring for mothers versus fathers of the same child.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.John's advisor suggests that John consider other factors, besides parental monitoring, such as the number of delinquent friends and the strength of future career aspirations that may contribute to delinquency.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.John is interested in studying delinquent behavior. He thinks that low parental monitoring will be associated with more delinquent behaviors among adolescents. He plans to measure monitoring using a self-report measure of how often parents ask their children where they are going, with who, and how often parents do not know where their children are, etc. The measure of delinquent behavior is the adolescents self-report of the number of times they have engaged in delinquent acts (e.g., shoplifting, driving under the influence, fighting, graffiti, etc) during the past year.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.Mary's advisor is involved in a project examining the frequency of acting out in a group of 100 adolescents who she is contacting at age 12, 13, 14, and 15 to examine trends in acting out over time.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.Another member of Mary's committee recommended that she change this to a factorial design. That is, some people should receive CBT only, some support group only, some both, and some should be a waitlist control. [Everyone on a dissertation committee thinks that the study should be redesigned to address the question in which they are most interested.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.Mary's advisor recommended that she add a third group, who are in a support only condition to her design.

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.Mary wants to know if an equal number of males and females volunteer for each of her groups (control group and CBT group).

Q: For each of the following examples, a) specify the independent and dependent variable b) note if they are categorical or continuous, c) note the type of question, and d) indicate which analysis would be most appropriate.Mary wants to know if there are treatment effects on acting out behavior (the number of incidents per month) between a group of adolescents who are in a wait list control group and a group of adolescents receiving Cognitive Behavioral Therapy (CBT).

Q: Goodness-of-fit chi-square is used when there is only one categorical variable being categorized.

Q: Distribution-free tests are used when there is a concern that the assumptions underlying parametric tests may be violated.

Q: An F value is frequently reported to describe the characteristics of a sample.

Q: A chi-square test is used when the independent and dependent variables are continuous.

Q: Repeated-measures ANOVA is used when comparing 2 or more related means.

Q: A related samples t-test is used to compare 2 related means.

Q: A factorial ANOVA is used when predicting more than one dependent variable.

Q: An independent samples t-test is used to examine mean differences between 3 or more independent groups.

Q: When you are interested in the degree of relationship between 1 continuous dependent variable and multiple continuous predictor variables you will most likely use a Spearman correlation.

Q: When you are interested in the degree of relationship between 2 continuous variables, you will most likely use Pearson correlation.

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.If we see a relationship over time between television violence and children's expression of aggression, we could conclude thata) violence causes aggression because people who watched violent television in third grade were also violent in third grade.b) people who watched a lot of violence in third grade also watched violence in twelfth grade.c) violence leads to aggression because violent TV is third grade was related to aggression in twelfth grade.d) violence leads to aggression because being aggressive in third grade leads to watching violence in twelfth grade.

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.We have the most persuasive evidence of some phenomenon whena) we have a very large sample.b) we have very accurate measurements.c) we have converging lines of evidence from a variety of studies.d) we have a single tightly controlled experiment.

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.If we wanted to compute a standardized mean difference () in student satisfaction, our best standard deviation to use in the calculation could bea) the average of the standard deviation of satisfaction scores in the fall and spring.b) a pooled standard deviation.c) the standard deviation of the scores collected from those students who used the new book.d) both a and b

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.How can we tell if the difference in the student opinion in the two semesters was a meaningful difference?a) rely on a statistical test of significanceb) calculate an r-family measure of statistical significancec) report a standardized mean differenced) report a simple mean difference

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.How might this study be improved?a) randomly sample students for the courseb) randomly assign students to take the course in the Fall or Springc) have a different instructor repeat the experiment using the texts in the opposite orderd) all of the above

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.What is the dependent variable in this study?a) test scoreb) answer to the evaluation questionc) both a and bd) neither a nor b

Q: An instructor in Introductory Psychology wanted to know if the textbook she was using was as effective as other textbooks on the market. In order to test this, she decided that she would teach the course in the fall with the text she typically uses, and in the spring she would use a new text. After doing this, she compared the students' final grades and students' responses to an 'end of semester' evaluation question. The question was "How effective was the text for this course?" She discovered that students' grades increased from a mean of 78 in the fall to 83 in the spring. She also discovered that the students' opinion of the course's text increased from a mean of 4.5 (on a 7-point scale, the higher the better) in the fall to 4.9 in the spring. After running the appropriate statistical test(s), she discovered that both of these differences were statistically significant.Which of the following tests would have been the most appropriate for this design?a) chi-square(s)b) correlation(s)c) t-test(s)d) multiple regression

Q: How might this study be "improved" as a conclusive test of the hypothesis that birds cause cancer?a) People should be randomly assigned to having a bird or not having a bird.b) People should be randomly assigned to the lung cancer group.c) The sample size should be greatly increased.d) None of these would help the situation.

Q: Without actually doing the arithmetic on paper, what conclusions would you be likely to draw from this study?a) Birds have nothing to do with lung cancer.b) Birds cause lung cancer.c) People who keep birds are more likely to have lung cancer.d) The data are inconclusive.

Q: Many studies have been conducted on the effects of having a pet on the response to medical problems and on mental health. But doctors in Berlin were interested in the effects of having a pet bird on lung cancer. (I assume they were wondering if birds might cause air pollution that could lead to lung cancer.) They asked 239 patients with lung cancer and 429 controls without lung cancer whether they had a pet bird. Ninety eight of the 239 patients did have a bird, while 101 of the 429 controls had a bird. (That strikes me as a very high percentage of bird owners, but those are the data.)What assumptions would need to underlie our analysis for this experiment?a) The observations are independent.b) There is no correlation between the variables.c) Expected values would be normally distributed.d) both a and c

Q: Many studies have been conducted on the effects of having a pet on the response to medical problems and on mental health. But doctors in Berlin were interested in the effects of having a pet bird on lung cancer. (I assume they were wondering if birds might cause air pollution that could lead to lung cancer.) They asked 239 patients with lung cancer and 429 controls without lung cancer whether they had a pet bird. Ninety eight of the 239 patients did have a bird, while 101 of the 429 controls had a bird. (That strikes me as a very high percentage of bird owners, but those are the data.)Why would it be wrong to calculate relative risk in this study?a) The study is a retrospective study.b) Relative risk rarely tells us anything.c) Risk is not a meaningful concept in this study.d) both b and c

Q: Many studies have been conducted on the effects of having a pet on the response to medical problems and on mental health. But doctors in Berlin were interested in the effects of having a pet bird on lung cancer. (I assume they were wondering if birds might cause air pollution that could lead to lung cancer.) They asked 239 patients with lung cancer and 429 controls without lung cancer whether they had a pet bird. Ninety eight of the 239 patients did have a bird, while 101 of the 429 controls had a bird. (That strikes me as a very high percentage of bird owners, but those are the data.)The odds of having cancer for the bird owners area) 98/239 = 0.41b) 98/(239 + 429) = 0.15c) 98/(239 - 98) = 0.70d) 98/101 = 0.97

Q: Many studies have been conducted on the effects of having a pet on the response to medical problems and on mental health. But doctors in Berlin were interested in the effects of having a pet bird on lung cancer. (I assume they were wondering if birds might cause air pollution that could lead to lung cancer.) They asked 239 patients with lung cancer and 429 controls without lung cancer whether they had a pet bird. Ninety eight of the 239 patients did have a bird, while 101 of the 429 controls had a bird. (That strikes me as a very high percentage of bird owners, but those are the data.)We really do need a measure of effect size in this example. What would be an appropriate one?a) the mean difference between bird owners and bird nonownersb) the squared correlation between ownership and cancerc) the odds ratiod) relative risk

Q: Many studies have been conducted on the effects of having a pet on the response to medical problems and on mental health. But doctors in Berlin were interested in the effects of having a pet bird on lung cancer. (I assume they were wondering if birds might cause air pollution that could lead to lung cancer.) They asked 239 patients with lung cancer and 429 controls without lung cancer whether they had a pet bird. Ninety eight of the 239 patients did have a bird, while 101 of the 429 controls had a bird. (That strikes me as a very high percentage of bird owners, but those are the data.)What would be the appropriate analysis to ask if bird ownership was significantly associated with lung cancer?a) at testb) a chi-square testc) a one-way ANOVAd) a correlation

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.If the experimenter had reason to believe that the data would be better analyzed by a nonparametric test, which would be the most appropriate test?a) Wilcoxon's signed-ranks matched-pairs testb) The Mann-Whitney testc) Kruskal-Wallis testd) The Friedman test.

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.What assumptions would the researcher have to make to analyze these data correctly?a) Homogeneity of variance across groupsb) Normality of the satisfaction scores within each group.c) Independence of observationsd) All of the above.

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.Why could the researcher not simply correlate the marital satisfaction score with the actual years of marriage?a) The anticipated relationship is not linear.b) The relationship is not curvilinear.c) The length of marriage variable is discrete.d) There will be too many outliers.

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.If there is a significant change with length of marriage, the researcher would finda) a large value of the test statistic.b) a small value of the test statistic.c) either very large or very small values.d) There is no way to know the size of the test statistic.

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.Which statistic would result from the appropriate analysis?a) Fb) tc) 2d) r

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.19 Which statistical analysis is most appropriate for testing this researcher's hypothesis?a) Pearson's correlationb) independent samples t-testc) one-way ANOVAd) repeated-measures ANOVA

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.What is the dependent variable?a) Length of marriageb) Passage of timec) Marital satisfactiond) Age of partners

Q: A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.What is the independent variable?a) Length of marriageb) Passage of timec) Marital satisfactiond) Age of partners

Q: A researcher is interested in the social behavior of mice. He hypothesizes that mice from Strain A will be more social than mice from Strain B, and Strain B will be significantly more social than mice from Strain C. Mice from each of the three different strains (20 mice in each strain) are raised in a laboratory. The mice are group housed with members of its own strain. All the mice receive the exact same amount of food, water, and light over the first 10 weeks of life. At 11 weeks of age, each mouse is placed in a cage with a novel mouse from his own strain. The mouse's investigatory behavior toward the other mouse is timed for 10 minutes.If the experimenter does decide to run this experiment again, what might the experimenter do to improve the chances of finding meaningful results?a) double the number of mice in the isolated conditionb) use an analysis of variance instead of a t testc) calculate an r-family measure of effect sized) calculate the power given the anticipated means and standard deviations

Q: A researcher is interested in the social behavior of mice. He hypothesizes that mice from Strain A will be more social than mice from Strain B, and Strain B will be significantly more social than mice from Strain C. Mice from each of the three different strains (20 mice in each strain) are raised in a laboratory. The mice are group housed with members of its own strain. All the mice receive the exact same amount of food, water, and light over the first 10 weeks of life. At 11 weeks of age, each mouse is placed in a cage with a novel mouse from his own strain. The mouse's investigatory behavior toward the other mouse is timed for 10 minutes.Given the above result, what might the experimenter do next?a) abandon the hypothesisb) run the experiment again with some mice group-housed and others singly-housedc) run the same statistical tests again to see if the results changed) both b and c

Q: A researcher is interested in the social behavior of mice. He hypothesizes that mice from Strain A will be more social than mice from Strain B, and Strain B will be significantly more social than mice from Strain C. Mice from each of the three different strains (20 mice in each strain) are raised in a laboratory. The mice are group housed with members of its own strain. All the mice receive the exact same amount of food, water, and light over the first 10 weeks of life. At 11 weeks of age, each mouse is placed in a cage with a novel mouse from his own strain. The mouse's investigatory behavior toward the other mouse is timed for 10 minutes.The researcher then decided to run the experiment again. This time mice of each strain were singly housed, isolated from members of their own strain for the 11 weeks. Now she finds that p = .048. This suggestsa) isolation reduces social interaction.b) the researcher's original hypothesis was correct.c) isolation might bring about strain differences in investigatory behavior.d) mice enjoy isolation.

Q: A researcher is interested in the social behavior of mice. He hypothesizes that mice from Strain A will be more social than mice from Strain B, and Strain B will be significantly more social than mice from Strain C. Mice from each of the three different strains (20 mice in each strain) are raised in a laboratory. The mice are group housed with members of its own strain. All the mice receive the exact same amount of food, water, and light over the first 10 weeks of life. At 11 weeks of age, each mouse is placed in a cage with a novel mouse from his own strain. The mouse's investigatory behavior toward the other mouse is timed for 10 minutes.If, after running the appropriate analysis, the researcher finds a result with p = .50, what can she conclude?a) Her hypothesis was supported by the analysis.b) Different strains of mice do exhibit significantly different levels of social behavior.c) Strain A is more social than Strain B, but not more than Strain C.d) Different strains of mice do not exhibit significantly different levels of social behavior.

Q: A researcher is interested in the social behavior of mice. He hypothesizes that mice from Strain A will be more social than mice from Strain B, and Strain B will be significantly more social than mice from Strain C. Mice from each of the three different strains (20 mice in each strain) are raised in a laboratory. The mice are group housed with members of its own strain. All the mice receive the exact same amount of food, water, and light over the first 10 weeks of life. At 11 weeks of age, each mouse is placed in a cage with a novel mouse from his own strain. The mouse's investigatory behavior toward the other mouse is timed for 10 minutes.Which statistical analysis is most appropriate for testing this researcher's hypothesis?a) One-way ANOVAb) Repeated-measures ANOVAc) Factorial ANOVAd) Independent samples t-test

Q: The Morris water maze is used to examine spatial learning in animals. Mice, who are good swimmers, are placed in a large pool of water and must learn to find a clear platform located just under the water surface. The platform is their only escape from the pool. If they do not find the platform, they have to continue swimming until we take them out.If we think that we may have some aberrant times, what is the best way to identify them?a) create a boxplotb) prepare a stem-and-leaf displayc) use a pie chartd) calculate the variance

Q: The Morris water maze is used to examine spatial learning in animals. Mice, who are good swimmers, are placed in a large pool of water and must learn to find a clear platform located just under the water surface. The platform is their only escape from the pool. If they do not find the platform, they have to continue swimming until we take them out.When mice perform in a Morris Water maze they sometimes become confused on a particular trial and take a long time to get to the platform. On other trials they are just lucky and go straight to it. How can we eliminate or reduce the influence of these unusual times?a) compare medians instead of meansb) use trimmed meansc) toss out scores that we don"t liked) both a and b

Q: The Morris water maze is used to examine spatial learning in animals. Mice, who are good swimmers, are placed in a large pool of water and must learn to find a clear platform located just under the water surface. The platform is their only escape from the pool. If they do not find the platform, they have to continue swimming until we take them out.We want to report an effect size estimate that reflects the fact that the animals were able to find the platform faster on the 10th trial that they did on the first trial. What would be the best measure to report?a) the difference in mean times on the two trials in questionb) the standardized difference in mean timesc) the correlation between performance on the first and tenth trialsd) the squared correlation between the two trials

Q: The Morris water maze is used to examine spatial learning in animals. Mice, who are good swimmers, are placed in a large pool of water and must learn to find a clear platform located just under the water surface. The platform is their only escape from the pool. If they do not find the platform, they have to continue swimming until we take them out.8 We want to compare the amount of time the mice spent swimming in the first trial to the amount of time they spent swimming in the tenth trial. What statistical test should be conducted on these data?a) t-testb) correlationc) factorial ANOVAd) one way ANOVA

Q: The Morris water maze is used to examine spatial learning in animals. Mice, who are good swimmers, are placed in a large pool of water and must learn to find a clear platform located just under the water surface. The platform is their only escape from the pool. If they do not find the platform, they have to continue swimming until we take them out.For one of the trials, the platform was removed from the pool and the amount of time the mouse spent in each of the four quadrants of the tank was recorded. What statistical test should be conducted on these data?a) t-testb) correlationc) factorial ANOVAd) repeated-measures ANOVA

Q: In an experiment aimed at evaluating the effect of a memory-enhancing drug on the recall of a previously learned response. Either the drug or a placebo was administered to different groups of rats before the memory test. There were three trials of the memory test, and the dependent variable was the time it took the animal to make the correct response.Why do we not need to use a multiple comparison procedure to compare the drug and control conditions?a) The difference is obvious.b) The difference is unimportant.c) There are only two groups.d) The test would not be appropriate unless we had at least four groups.

Q: In an experiment aimed at evaluating the effect of a memory-enhancing drug on the recall of a previously learned response. Either the drug or a placebo was administered to different groups of rats before the memory test. There were three trials of the memory test, and the dependent variable was the time it took the animal to make the correct response.It seems reasonable that there is some sort of relationship between the number of trials it took to learn a response and the speed of response on the test trials. It would be interesting to know how the drug affects this relationship. How might you go about looking at this question?a) Run a t test between the two groups' performance on the first test trial.b) Correlate the number of learning trials with the speed of performance on the test trials.c) Correlate number of learning trials and speed on test trials separately for the two drug conditions.d) Use the Mann-Whitney test to compare the groups.

Q: In an experiment aimed at evaluating the effect of a memory-enhancing drug on the recall of a previously learned response. Either the drug or a placebo was administered to different groups of rats before the memory test. There were three trials of the memory test, and the dependent variable was the time it took the animal to make the correct response.We want to compute an effect size estimate for the difference between drug and placebo treatments. We will take as our dependent variable for this computation each animal's mean response time over the three trials. What would be the best estimate of effect size?a) The difference between the means of the two groups.b) The difference between the group means divided by the square root of the pooled variance estimate.c) The difference between the means divided by the standard deviation of the control group.d) None of the above would be of any value.

Q: What assumption(s) would we need to make for this analysis?a) The observations are independent.b) The observations are normally distributed.c) The animals are randomly assigned to drug treatmentsd) both b and c

Q: Suppose the analysis reveals a significant drug by trial interaction. What would we conclude about the effect of the drug on memory?a) The effect of the delay is different for the drug and the placebo.b) The drug has no effect on memory.c) The trials have no affect on memory.d) No conclusion can be reached without looking at the percent correct responses.

Q: In an experiment aimed at evaluating the effect of a memory-enhancing drug on the recall of a previously learned response. Either the drug or a placebo was administered to different groups of rats before the memory test. There were three trials of the memory test, and the dependent variable was the time it took the animal to make the correct response.The proper analysis to evaluate the drug enhancement of memory is a(n)a) t-test.b) ANOVA with a within-subjects effect of trials.c) one-way ANOVA.d) factorial ANOVA.

Q: 45 A critic for the Food Network asked five world-renown chefs to taste three types of olive oil and rate them on a scale from 0 to 100 where 100 represents the highest quality. Analyze and interpret the following data using the Friedman test.Chef Oil 1 Oil 2 Oil 31 50 100 02 75 95 253 45 70 304 55 85 405 65 90 15

Q: 44 A Pediatrician wants to know if number of children in the family is related to how early parents arrive for regularly scheduled pediatric visits. The data follow in terms of the number of minutes early. Analyze and interpret the data using the Kruskal-Wallis procedure.1 Child 2 Children 3 or More Children10 1 08 0 015 2 2.55 3 1.759 1.5 2.7512 20 6.514 7 1311 6 0.521 4

Q: 43 Re-analyze the previous data using the normal approximationa) Calculate and interpret z.b) Which analysis is more appropriate? Explain.

Q: 42 A teacher wanted to see if her students could complete a multiplication review sheet more quickly after practicing for a week. The total number of seconds it took each time are reported below. Calculate Wilcoxon's matched pairs signed ranks test on the following data and describe the results.Student 1 2 3 4 5 6 7 8 9 10 11Before 60 75 48 90 30 55 75 80 90 85 60After 50 60 49 75 35 45 68 59 92 70 50

Q: 41 Re-analyze the previous data using the normal approximation. a) Calculate z and describe your conclusions. b) Which analysis is more appropriate for these data? Explain.

Q: 40 The following depression data using the two-tailed Mann-Whitney test. Describe your conclusions.Experimental ControlGroup Group 150 90140 4080 10070 60220 200360 150190

Q: 39 Under what conditions would you calculate in the Mann-Whitney test?

Q: 38 In a Kruskal-Wallis one-way analysis of variance, would you retain or reject the null hypothesis given the following information: a) H = 15.6, df = 8 b) H = 35.75, df = 25 c) H = 45.7, df = 30

Q: 37 Would you reject or retain the null hypothesis in a Wilcoxon's matched-pairs signed rank test given the following information and assuming a one-tailed test and = .05:a) n = 5, T = 0b) n = 12, T = 19c) n = 28, T = 129

Q: 36 Would you reject or retain the null hypothesis in a Mann-Whitney test given the following information and assuming a one-tailed test and = .05:a) n1 = 1, n2 = 25, W = 3b) n1 = 5, n2 = 6, W = 14c) n1 = 8, n2 = 9, W = 60

Q: 35 The ranks of these numbers: 1, 5, 2, 4, 5 are 1, 4.5, 2, 3, 4.5.

Q: 34 Friedman's rank test for k-related samples is to Wilcoxon's matched-pairs signed ranks test as a repeated-measures ANOVA is to a paired samples t-test.

Q: 33 As the sample size increases, non-parametric statistics approach normal.

Q: 32 When using Wilcoxon's matched pairs-signed ranks test, the rank of the difference between related scores is calculated.

Q: 31 Friedman's rank test for k-correlated samples is used to assess the degree of association between ranks, much like a correlation coefficient.

Q: 30 The Mann-Whitney test is used to compare the rank scores of two groups.

Q: 29 In distribution-free tests, you usually reject the null hypothesis when the obtained value is smaller than the critical value.

Q: 28 Distribution free tests are more sensitive to means than to medians.

Q: 27 Distribution-free tests tend to be greatly affected by outliers.

Q: 26 Non-parametric tests are those that do not rely on parameter estimation or strong assumptions about distributions.

Q: 25 The Mann-Whitney test is to independent samples t test as Wilcoxon's matched-pairs signed-ranks test is to a) Kruskal-Wallis ANOVA. b) one-way repeated-measures ANOVA. c) related sample means t-test. d) Friedman's rank test for k correlated samples.

Q: 24+ One major argument promoting the use of parametric tests over distribution-free tests is that parametric tests are a) easier to calculate. b) usually robust enough to be unaffected by violation of assumptions. c) less affected by outliers than distribution-free tests. d) used less frequently and therefore must be more elite.

Q: 23 The Friedman test a) ranks the scores within each subject. b) is appropriate when we have several repeated measures on each subject. c) is largely insensitive to outliers. d) all of the above