Exam 13: Correlation Research

A general aptitude test correlates .45 with success in a particular college.To improve the predictive accuracy, the students are also given three other aptitude measures, all of which correlate very highly with one another and with the first test.What will be the likely effect of adding the scores from the three additional tests to the regression equation?

If a computed Pearson's correlation coefficient is statistically significant at the .01 level,

Why would a correlation of -.5 be just as useful as a correlation of .5?

A study with college students found no correlation between hours of study for an examination and test performance.This probably means

Exhibit 13-6: A researcher collects the following measures on a sample of college students: scores on the SAT and the ACT, scores on an English composition test, high school class rank, scores on a noncognitive measure, whether or not students successfully completed the first year of college (pass-fail), and their GPA.Choose the statistical procedures that the researcher should use to answer the following questions. -Refer to Exhibit 13-6.What is the correlation between the combination of independent variables and GPA at the end of the freshman year as dependent variable?

Exhibit 13-6: A researcher collects the following measures on a sample of college students: scores on the SAT and the ACT, scores on an English composition test, high school class rank, scores on a noncognitive measure, whether or not students successfully completed the first year of college (pass-fail), and their GPA.Choose the statistical procedures that the researcher should use to answer the following questions. -Refer to Exhibit 13-6.Do all the measures used in this study measure something in common?

Exhibit 13-3: Compare the following coefficients of correlation and their corresponding Ns, then answer the questions.Notice that all correlation values are statistically significant. -Refer to Exhibit 13-3.Which coefficient of correlation is least significant?

If a test is going to predict a criterion well, the correlation between the test and the criterion should be

An advantage of correlational studies is that such studies

A researcher found a correlation of .40 between aptitude test scores and school achievement.What proportion of the variance in school achievement can be attributed to variables other than aptitude?

Assume you are using GRE scores and undergraduate grades to predict graduate GPA.If the correlation of GRE scores and undergraduate grades were .18 rather than .56, then GRE scores would be ____ for predicting graduate GPA.

In a sample of 18, the correlation between intelligence test scores and creativity test scores was found to be .40.Do these data provide evidence for a significant relationship between these variables in the population? Test at the .05 level of significance (two tailed).Table A5 shows a correlation of .4683 for 16 degrees of freedom.

The process of applying a prediction equation to another sample independent of the sample on which the equation was calculated is called

If a relationship between two variables is spurious, we conclude that it is

How are these three coefficients related mathematically?

One wants to find the correlation between social adjustment and achievement with the effects of intelligence controlled.The appropriate index to use is

The correlation between SAT and GPA would be lowest for which one of the following populations?

The following graph resulted when a researcher plotted the paired scores from two sets of data: Which of the following conclusions is justified from an examination of the graph?

The correlation between the Graduate Record Examination (GRE) and undergraduate GPA for all people taking the GRE is .56.If the correlation is recomputed for only those students admitted to graduate school, the value of the correlation will most likely

Other things being equal, as the sample size increases the critical value for the Pearson's r