Description

A large survey study of college freshmen at 8 institutions reports that the correlation between combined SAT scores and freshman year grade-point average is .30.

1.       What proportion of the total variance in grade-point average is accounted for or explained?

by combined SAT scores?

a.    .30

b.    .09

c.    .70

d.    .07

e.    .49

2.       What proportion of the total variance in freshman grade-point average is explained by variables or factors OTHER than combined SAT scores?

a.    .90

b.       .70

c.       .30

d.       .40

e.    .51

Use the following to answer questions 3-4:

In studying the correlates of tested intelligence on a sample of 10,000 college freshmen randomly selected from all entering freshmen in the country, a sociologist reports a correlation of .26 between socio-economic status (SES) and scores on the Stanford-Binet intelligence Test. The correlation is statistically significant at the .05 level (p < 05).

3.       Which of the following is the most accurate explanation of what the statistically significant correlation means in the above study?

4.        

a.    The correlation is very important

b.    If the correlation between SES and intelligence in the population is .00, a sample correlation of .26 should be observed by chance in less than 5 in every 100 samples (of size 10,000)

c.    If the correlation between SES and intelligence in the population is .00, a sample correlation of .26 should be observed by chance in more than 5 in every 100 samples (of size 10,000).

d.    If the correlation between SES and intelligence in the population is .00. a sample correlation of .26 should be observed by chance in more than 95 in every 100 samples (of size 10,000)

4.       Which of the following is the most appropriate conclusion drawn from the finding?

a.    Socio-economic status causes variations in intelligence

b.    The observed correlation is probably the result of sampling errors and should be ignored

c.    Intelligence causes variations in socioeconomic status

d.    Variations in socio-economic status and intelligence tend to be positively related 

e.    Socio-economic status and intelligence have no causal relationship

Use the following to answer questions 5-11:

A University administration thinks that an experimental freshman living-learning residence arrangement, which includes faculty living in student residences, will have a more positive effect on student critical thinking ability than will conventional freshman residences. All incoming freshmen are routinely administered a measure of "critical thinking" of demonstrated reliability and validity. Because of university policy, students are allowed to self-select themselves into residence arrangements. At the end of the freshman year the measure of critical thinking ability is re-administered to random samples of 100 students in the experimental and 100 students in the conventional living arrangements. The mean critical thinking ability gain score (i.e., posttest - pretest) of the experimental group is then compared to the corresponding gain score of the conventional group.

5.      The study would be most appropriately classified as:

a.    An ex post facto study

b.   An experimental study

c.    A quasi-experimental study

d. · A correlational study

e.    None of the above

6.      The "control  group" would be those who:

a.    Live in the living-learning residence

b.    Live in the conventional student residences

c.    Have high levels of critical thinking ability in either residence arrangement

d:  .   Are not selected as subjects in the study but who live in the conventional residences

7.      The design of the study would be classified as:

a.   Solomon, four-group design

b.    One group posttest only design

c.    Experimental group, control group, pretest-posttest design

d.    Non-equivalent experimental group-control group, pretest-posttest design

e.    Both a and c

8.      The independent variable in the study is:

a.      The year in which the study was conducted

b.    School size

c.       Critical thinking ability

d.    Residence arrangement

e.    None of the above

9.      The dependent variable in the study is:

a.    The year in which the study was conducted

b.    School size

c.    High school rank in class

d.    Residence arrangement

e.    None of the above

10.    Which of the following is the greatest threat to the internal validity of the study?

a.    Regression to the mean

b.    Interaction of selection and maturation/change

c.    Interaction of testing and the treatment

d.    The reactive arrangements of the experimental program

e.    Instrument decay

11.   Which of the following is the greatest threat to the external validity of the study?

a.    History

b.    Regression toward the mean

c.    The reactive arrangements of the experimental program

d.    Interaction of testing and the treatment

e.    Maturation

Use the following to answer questions 12-15:

A researcher in a small school district has developed an innovative program for improving student reading skills over conventional programs. In order to test the worth of her experimental program she randomly selects one first grade class from each of the two elementary schools in the district. Each class is randomly assigned to either the experimental or the conventional treatment. Before undergoing the treatment, students are pretested with a measure of reading skills which is of demonstrated reliability and validity. At the end of the treatment, students in both programs are post-tested with the same measure and the posttest means compared. The observed difference between the two means is 6.35 points which is found to be statistically significant at the .05 level (p <

.05).