Exam 21: Meta-Analysis

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?

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?

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

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

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. What assumption(s) would we need to make for this analysis?

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 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?

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 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?

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 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?

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.

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 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?

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.

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?

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. ☺]

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?

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

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 that

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?