Interpreting main effects and interactions in 2 x 2 designs Imagine that I am interested in finding ways to improve memo
Posted: Tue Jul 12, 2022 1:21 pm
Interpreting main effects and interactions in 2 x 2 designs
Imagine that I am interested in finding ways to improve memoryperformance in older adults. After doing some research, I find thatphysical exercise might be an important factor in mental health. Idecide to run an experiment to test whether cardiovascular exercisecan improve memory performance. In my experimental design, I havetwo independent variables: testing time (pretest vs. post test),and exercise group (no exercise vs. exercise). For pretest andposttest, participants studied a list of words and then recalledthem. However, the two tests were separated by 5 days. For theexercise group, in between pre test and post test, participantsengaged in cardiovascular exercise for 5 days in a row. The noexercise group were not made to exercise in between pre test andpost test. The dependent variable was how many words they recalledcorrectly on the pre test and post test. My hypothesis is thatcardiovascular exercise will improve memory functioning.
Data set #1 Number of words recalled 35 30 0 No exercise Exercise Pre test Post test Exercise group 1) Are there any main effects? If so, what are they? Describe the nature of the effects. 2) Is there an interaction? Describe the interaction by describing the simple effects. 3) Was my hypothesis supported? What can we say about exercise and memory improvement?
Data set #2 Number of words recalled 35 30 25 20 10 5 0 L L No exercise Exercise Pre test Post test Exercise group 1) Are there any main effects? If so, what are they? Describe the nature of the effects. 2) Is there an interaction? Describe the interaction by describing the simple effects. 3) Was my hypothesis supported? What can we say about exercise and memory improvement?
Imagine that I am interested in finding ways to improve memoryperformance in older adults. After doing some research, I find thatphysical exercise might be an important factor in mental health. Idecide to run an experiment to test whether cardiovascular exercisecan improve memory performance. In my experimental design, I havetwo independent variables: testing time (pretest vs. post test),and exercise group (no exercise vs. exercise). For pretest andposttest, participants studied a list of words and then recalledthem. However, the two tests were separated by 5 days. For theexercise group, in between pre test and post test, participantsengaged in cardiovascular exercise for 5 days in a row. The noexercise group were not made to exercise in between pre test andpost test. The dependent variable was how many words they recalledcorrectly on the pre test and post test. My hypothesis is thatcardiovascular exercise will improve memory functioning.
Data set #1 Number of words recalled 35 30 0 No exercise Exercise Pre test Post test Exercise group 1) Are there any main effects? If so, what are they? Describe the nature of the effects. 2) Is there an interaction? Describe the interaction by describing the simple effects. 3) Was my hypothesis supported? What can we say about exercise and memory improvement?
Data set #2 Number of words recalled 35 30 25 20 10 5 0 L L No exercise Exercise Pre test Post test Exercise group 1) Are there any main effects? If so, what are they? Describe the nature of the effects. 2) Is there an interaction? Describe the interaction by describing the simple effects. 3) Was my hypothesis supported? What can we say about exercise and memory improvement?