Question

A researcher interviewed 68 pregnant inner city woman and their male partners twice during their pregnancy. The interviews were about three months apart. The accompanying table shows the correlations among several of their measures. Complete parts (a) through (c) below. HE Click the icon to view the table of correlations. ww be (a) Explain what is meant by a correlation coefficient, using one of the correlations as an example, as if writing to a person who has never had a course in statistics Choose the correct answer below. ww O A. A correlation coefficient tells about the probability of a positive or negative change in a variable. The correlation coefficient between Depressed Mood 1 and So Depressed Mood 2 of 0.56 shows that women were 56% more likely to be depressed in the second interview than in the first. As OB. A correlation coefficient tells the strength and direction of a linear relationship. The correlation coefficient belween Depressed Mood 1 and Depressed Mood 2 ther of 0.58 shows a fairly strong positive relationship; women with more depression at the first interview tended to have more depression at the second Interview You O C. A correlation coefficient tells about change in a variable between two measurements. The correlation coefficient between Depressed Mood 1 and Depressed Mood 2 of 0.56 shows that women were 56% more depressed in the second interview 0) Comment on the patters of results in terms of which variables are relatively strongly correlated and which are not very strongly correlated as if writing to a person who has never had a course in statistics. Choose the correct answer below. Sa O A Men's report of women's sro, Depressed Mood 1 and Party have the strongest comelations, as they have the greatest number of positive coefficients. Sas Partner Support 2 has the weakest correlations, as it has the greatest number of negative coefficients The OB. Most of the strongest correlations are the most logical relationships, such as among and between Depressed Moods and Partner Supports. Most of the weakest correlations are the least logical relationships, such as age and ethnicity deg OC. Party is strongy correlated to the other variables, since it has the longest row. Women's report of stress is not strongly correlated to the other variables, since it has the shortest row. (c) Comment on the limitations of making conclusions about the direction of causalty based on these data, using a specific correlation as an example, as if writing to a person who has never had a course in statistics. Choose the correct answer below. Sa As Click to select your answer As You ww Rei

Answer 1

(a)

B. The correlation coefficient tells the strength and direction of a linear relationship. The correlation coefficient between Depressed mood 1 and Depressed mood 2 of 0.56 shows a fairly strong positive relationship; women with more depression at the first interview tended to have more depression at the second interview.

(b)

B. Most of the strongest correlations are the most logical relationships, such as among and between Depressed Moods and Partner Supports. Most of the weakest correlations are the least logical relationships, such as age and ethinicity

(c)

B. Depressed Moods 1 and 2 have a fairly strong positive correlation, but Depressed Mood 2 could not cause Depressed Mood 1 because Depressed Mood 1 was asked for and recorded about three months before Depressed Mood 2.