4) A researcher has tested participants in four independent conditions: training, training and feedback, training and reward, control. She wishes to compare the feedback and reward condition against the training and control conditions as an a priori comparison. What coordinates could be used for the linear contrast?
A) -1, -1, 0, 0
B) 1, 1, 0, 0
C) 2, -2, 0, 0
D) 1, 1, -1, -1

Question

Quizplus · Accepted Answer

A linear contrast is used to test for a specific comparison among the conditions in a study. In this case, the researcher wants to compare the feedback and reward condition against the training and control conditions. Therefore, the coordinates for the linear contrast should be positive for the feedback and reward condition and negative for the training and control conditions. Option D provides the proper coordinates for this comparison (1, 1, -1, -1).

4) a Researcher Has Tested Participants in Four Independent Conditions