Question

Sandra has a group of undergraduate students fill out a questionnaire measuring clinical depression once per week for two months, and finds that each student tends to score quite similarly to what they had scored in previous weeks. Sandra finds that the score on her questionnaire is independent of whether or not an individual is clinically depressed. Which of the following best describes the features of Sara's questionnaire?

1) Sandra's measure has strong reliability and strong validity.
2) Sandra's measure has weak reliability but strong validity.
3) Sandra's measure has strong reliability but weak validity.
4) Sandra's measure has weak reliability and weak validity.

Answer 1

Sandra's questionnaire has strong reliability but weak validity because each student tends to score similarly over time, but the score on the questionnaire is not dependent on clinical depression.

Step-by-step explanation:

Sandra's measure has strong reliability but weak validity.

Reliability refers to the consistency of an instrument over time, and Sandra's questionnaire demonstrates strong reliability because she found that each student tends to score similarly to their previous scores. However, validity refers to the accuracy of an instrument in measuring what it intends to measure, and in Sandra's case, her questionnaire is not valid because the score on the questionnaire is independent of whether or not an individual is clinically depressed.

Therefore, option 3) Sandra's measure has strong reliability but weak validity best describes the features of Sandra's questionnaire.