Exam 11: The Hypothesis of Association: Correlation

A "significant" correlation is one which

In doing a Pearson r on 20 pairs of scores, degrees of freedom would equal

Questions below are based on the following. A group of 10 college sophomores was randomly selected and given a personality test that measured both orderliness and rebelliousness. The scores were as follows: Subject \# Orderliness Rebelliousness 1. 9 6 2. 6 8 3. 12 2 4. 7 6 5. 10 10 6. 4 11 7. 9 11 8. 10 9 9. 9 9 10. 2 13 -What conclusions might you draw?

For a given sample size, the Pearson r is more likely to show significance than is the Spearman r.

When both sets of measures are in ordinal form, the appropriate correlational technique should be

In general, the array of points on a scatter plot tends to form the shape of

When one set of measures is in interval form, and the other in ordinal, then the appropriate correlational technique should be

Calculate the t ratio, and make a statistical decision at the .05 level for the following combinations of r and N. a. r = .25 and N = 31 b. r = .25 and N = 62 c. r = .60 and N = 27 d. r = .70 and N = 15

When a relationship is inverse it means that the correlation must be

When a correlation is discovered between two variables, A and B, it is possible, though not certain that

Any Pearson r which is significant at an alpha of .01, must also

Of the following correlation coefficients, which expresses the strongest association?

When attempting to assess the correlation between two distributions, X and Y, if either of the two variables fail to contain the high or low end of its distribution, the resulting coefficient will tend to over-estimate the true correlation in the population.

If the correlation between X and Y is zero, and the correlation between X and Z is zero, then the correlation between Y and Z should be zero.

The Following Questions will be based on the following: A group of 10 college seniors was randomly selected and given a WAIS-III IQ test. The IQs were recorded and then compared with each student's rank in class. The data are as follows: Student\# IQ Rank In Class 1. 120 1 2. 125 2 3. 122 3 4. 110 4 5. 95 5 6. 105 6 7. 100 7 8. 110 8 9. 100 9 10. 94 10 -Which correlation technique must therefore be applied?

A researcher has computed two significant Pearson r values from independent random samples. Sample A, 60 subjects, produced an r of .98 and Sample B, 50 subjects, produced an r of .71. Do the two sample correlations represent a common population correlation?

The correlation between the two variables is generally

Whenever interval data are converted into ordinal data,

For the Spearman r, the degrees of freedom are established in the same way as for the Pearson r.

All positive correlations predict with a higher level of accuracy than do all negative correlations.