Suppose a counseling psychologist sets out to see whether the age of entering the relationship is related to relationship longevity. He decides to measure relationship satisfaction in a group of couples formed when the younger partner was younger than 30 and a group of couples formed when the younger partner was 30 or older. He chooses the Marital Satisfaction Inventory because it refers to “partner” and “relationship” rather than “spouse” and “marriage,” which makes it useful for research with both traditional and nontraditional couples. Higher scores on the Marital Satisfaction Inventory indicate greater relationship satisfaction.The psychologist administers the Marital Satisfaction Inventory to 85 couples—31 are couples formed when the younger partner was younger than 30 and 54 are couples formed when the younger partner was 30 or older. He wants to calculate the correlation between a couple’s relationship satisfaction and whether the younger partner was younger or older than 30 at the beginning of the relationship. Which of the following types of correlations would be most appropriate for the psychologist to use?A phi-correlation A Pearson correlation A point-biserial correlation A Spearman correlation To calculate the correlation, the psychologist converts “the age of entering the relationship” to a dichotomous variable. Suppose the data for the first 5 couples he surveys are shown in the table that follows. By assigning one (1) to couples formed when the younger partner was younger than 30 and zero (0) to couples formed when the younger partner was 30 or older, complete the table.Age of the Younger PartnerMarital Satisfaction Inventory ScoreAge of the Younger Partner (Converted)younger than 3020 younger than 3041 30 or older18 30 or older46 younger than 3032 Suppose the psychologist calculates the correlation using the data as coded in the previous table. Then, he recalculates the correlation, but this time, instead of assigning one (1) to couples formed when the younger partner was younger than 30 and zero (0) to couples formed when the younger partner was 30 or older, he reverses the codes and assigns zero (0) to couples formed when the younger partner was younger than 30 and one (1) to couples formed when the younger partner was 30 or older. Which of the following statements is true regarding his two calculations of the correlation?The absolute values of the two correlations are different. The two correlations are the same. The signs of the two correlations are opposite, but their absolute values are the same. Before calculating the correlation, the psychologist does an independent-measures t test comparing the Marital Satisfaction Inventory scores of couples formed when the younger partner was younger than 30 and couples formed when the younger partner was 30 or older. The value of the t statistic is 2.63 with 83 degrees of freedom. Using this information, the square of the point-biserial correlation is r² = .

Question

Suppose a counseling psychologist sets out to see whether the age of entering the relationship is related to relationship longevity. He decides to measure relationship satisfaction in a group of couples formed when the younger partner was younger than 30 and a group of couples formed when the younger partner was 30 or older. He chooses the Marital Satisfaction Inventory because it refers to “partner” and “relationship” rather than “spouse” and “marriage,” which makes it useful for research with both traditional and nontraditional couples. Higher scores on the Marital Satisfaction Inventory indicate greater relationship satisfaction.The psychologist administers the Marital Satisfaction Inventory to 85 couples—31 are couples formed when the younger partner was younger than 30 and 54 are couples formed when the younger partner was 30 or older. He wants to calculate the correlation between a couple’s relationship satisfaction and whether the younger partner was younger or older than 30 at the beginning of the relationship. Which of the following types of correlations would be most appropriate for the psychologist to use?A phi-correlation A Pearson correlation A point-biserial correlation A Spearman correlation  To calculate the correlation, the psychologist converts “the age of entering the relationship” to a dichotomous variable. Suppose the data for the first 5 couples he surveys are shown in the table that follows. By assigning one (1) to couples formed when the younger partner was younger than 30 and zero (0) to couples formed when the younger partner was 30 or older, complete the table.Age of the Younger PartnerMarital Satisfaction Inventory ScoreAge of the Younger Partner (Converted)younger than 3020 younger than 3041 30 or older18 30 or older46 younger than 3032  Suppose the psychologist calculates the correlation using the data as coded in the previous table. Then, he recalculates the correlation, but this time, instead of assigning one (1) to couples formed when the younger partner was younger than 30 and zero (0) to couples formed when the younger partner was 30 or older, he reverses the codes and assigns zero (0) to couples formed when the younger partner was younger than 30 and one (1) to couples formed when the younger partner was 30 or older. Which of the following statements is true regarding his two calculations of the correlation?The absolute values of the two correlations are different. The two correlations are the same. The signs of the two correlations are opposite, but their absolute values are the same.  Before calculating the correlation, the psychologist does an independent-measures t test comparing the Marital Satisfaction Inventory scores of couples formed when the younger partner was younger than 30 and couples formed when the younger partner was 30 or older. The value of the t statistic is 2.63 with 83 degrees of freedom. Using this information, the square of the point-biserial correlation is r² =    .

Accepted Answer

There are two variables, one is Marital satisfactory inventory score (a continuous variable) and…

Age of the Younger Partner	Marital Satisfaction Inventory Score	Age of the Younger Partner (Converted)
younger than 30	20
younger than 30	41
30 or older	18
30 or older	46
younger than 30	32