Ordinal - allow us to rank order the levels of the variables being studied; instead of having categories that are simply different as in nominal scale, the categories can be ordered from first to last [Ex. ranking TV shows by popularity, 2- 3- 4- star restaurants]
Interval - the difference between the numbers on the scale is meaningful, the intervals between the numbers are equal in size [Ex. intelligence, aptitude test score, temperature] [although these scales might have a zero point, that zero is an arbitrary reference point and does not indicate the absence of that variable]
Ratio - has an absolute zero point that indicates the absence of the variable being measured [Ex. reaction time, weight, age, frequencies of behaviors].
Classify each result below as an example of face validity, content validity, convergent and discriminant validity, or criterion validity.
a. A professor gives a class of 40 people his five-item measure of conscientiousness [e.g., "I get chores done right away", "I follow a schedule," "I do not make a mess of things"]. Average scores are correlated [r = -.20] with how many times each student has been late to class during the semester
b. A professor gives a class of 40 people his five-item measure of conscientiousness [e.g., "I get chores done right away", "I follow a schedule," "I do not make a mess of things"]. Average scores are highly correlated with a self-report measure of tidiness [ r = .50] than with a measure of general knowledge [ r = .09]
c. The researcher e-mails his five-item measure of conscientiousness [e.g., "I get chores done right away", "I follow a schedule," "I do not make a mess of things"] to 20 experts in personality psychology, and asks them they think his items are a good measure of conscientiousness.
d. The researcher e-mails his five-item measure of conscientiousness [e.g., "I get chores done right away", "I follow a schedule," "I do not make a mess of things"] to 20 experts in personality psychology, and asks them if they think he has included all the important aspects of conscientiousness.
Reading the news on the Internet, Johan comes across the headline, "When Stress is Increased, Men Rush Ahead, Women More Cautious." [This headline is based on a study conducted by Lighthall et al., 2011.] In this study, men and women were asked to perform a decision task as many times as possible in a set period, in either a stressed or unstressed condition. In the unstressed condition, men and women performed similarly. However, in the stressed condition, the number of decision tasks performed by men increased while the number performed by women decreased. In this study, the number of decision tasks performed is best described as which of the following?
A. a constant
B. a level of a variable
C. a manipulated variable
D. a measured variable
Reading the news on the Internet, Johan comes across the headline, "When Stress is Increased, Men Rush Ahead, Women More Cautious." [This headline is based on a study conducted by Lighthall et al., 2011.] In this study, men and women were asked to perform a decision task as many times as possible in a set period, in either a stressed or unstressed condition. In the unstressed condition, men and women performed similarly. However, in the stressed condition, the number of decision tasks performed by men increased while the number performed by women decreased. Which of the following is a constant in this study?
A. the amount of time to perform the decision task
B. sex of the participants
C. the amount of stress
D. number of decision tasks performed
Reading the news on the Internet, Johan comes across the headline, "When Stress is Increased, Men Rush Ahead, Women More Cautious." [This headline is based on a study conducted by Lighthall et al., 2011.] In this study, men and women were asked to perform a decision task as many times as possible in a set period, in either a stressed or unstressed condition. In the unstressed condition, men and women performed similarly. However, in the stressed condition, the number of decision tasks performed by men increased while the number performed by women decreased. Which of the following is a variable in this study?
A. the decision task type
B. the length of the set period
C. the amount of stress
D. the cause of the stress