PS307 | Your Names: ________________________________________
Identifying Good Measures | Class Activity
Instructions. Working in small groups, complete the following:
1. Classify each operational variable below as categorical or quantitative. If the variable is quantitative, further classify it as ordinal, interval, or ratio.
A. Degree of pupil dilation in a person’s eyes in a study of romantic couples (measured in millimeters)
B. Number of books a person owns.
C. A book’s sales rank on Amazon.com
D. Location of a person’s hometown (urban, rural, or suburban)
E. Nationality of the participants in a cross-cultural study of Canadian, Ghanaian, and French students.
F. A student’s earned grade in school (A, B, C, D, F).
A. Quantitative, ratio
B. Quantitative, ratio
C. Quantitative, ordinal
D. Categorical
E. Categorical
F.
2. For each measure below, indicate which kinds of reliability would need to be evaluated. Then, draw a scatterplot indicating that the measure has good reliability and another one indicating the measure has poor reliability. (Pay attention to how you label the axes of your scatterplots.). You could doodle on a piece of paper or try to use the Draw feature (e.g., Insert > Drawing).
A. Researchers place unobtrusive video recording devices in the living rooms of 20 children. Later, coders view tapes and code how many minutes each child spends playing video games.
B. Clinical psychologists have developed a seven-item self-report measure to quickly identify people who are at risk for panic disorder.
C. Psychologists measure how long it takes a mouse to learn an eyeblink response. For 60 trials, they present a mouse with a distinct blue light followed immediately by a puff of air. The 5th, 10th, and 15th trials are test trials, in which they present the blue light alone (without the puff of air). The mouse is said to have learned the eyeblink response if observers record that it blinked its eyes in response to the blue light test trial. The earlier in the 60 trials the mouse shows the eyeblink response, the faster it has learned the response.
D. A restaurant owner uses a response card with four items in order to evaluate how satisfied customers are with the food, service, ambience, and overall experience. Each item is scaled from one to four stars.
E. Educational psychologists use teacher ratings of classroom shyness (on a nine-point scale, where 1 = “not at all shy in class” and 9 = “very shy in class”) to measure children’s temperament.
A.
3. Consider how you might validate the nine-point classroom shyness rating example in question 2e above.
A. First, what behaviors might be relevant to use to test this rating’s criterion validity? Draw a scatterplot showing the results of a study in which the classroom shyness rating has good criterion validity (be careful how you label the axes).
B. Second, come up with ways to evaluate the convergent and discriminant validity of this rating system. What traits should correlate only weakly or not at all? Explain why you chose those traits. Draw a scatterplot showing the results of a study in which the shyness rating has good convergent or discriminant validity (be careful how you label the axes).