In Each of the Following Examples, Identify the Independent and Dependent

In each of the following examples, identify the independent and dependent variables. Discuss which independent variables are manipulated variables.
a. The comparative effectiveness of programmed instruction on the computational skills of 9th graders.
b. The effect of self paced versus teacher pacing instruction on self-concept of 4th, 5th, and 6th graders.
c. The effect of employment status of mothers on school absenteeism of their children
d. The effect of sex on algebra achievement