0266 Independent Measures and Repeated Measures Design

Which of the following best describes independent measures design?

• The same participants take part in all conditions.

• Different participants are used in each condition of the IV

• The same participants are tested at different times.

• Participants choose which condition they take part in.

What is one main problem with independent measures design?

• Order effects such as practice and fatigue

• Practice effects making some participants better at the task

• Individual differences between groups such as one group might be better at the task from the start

• All participants drop out and affect the results of the study

A psychologist divides participants into two groups to test if background music affects reading speed. What should they do to reduce individual differences and bias between the groups?

• Put all high-achieving readers in one group and low-achieving readers in the other

• Let participants choose which group they want to be in

• Randomly allocate participants so each group is likely to have a fair mix of abilities

• Test both groups at different times of day to see what happens

A researcher asks participants to complete a memory test first while listening to music, then again in silence. What issue might affect the results in this repeated measures design?

• Too many participants are used so the results get affected

• Random allocation can’t be applied

• Participants might improve simply because they’ve done the task before or get worse because they are tired

• Each participant only takes part in one condition

What is counterbalancing used for?

• Ensuring participants guess the aim

• Making all participants complete the same task

• Controlling order effects such as fatigue & practice in repeated measures

• Randomly assigning participants to groups

A study tests students with and without music. All students do both conditions on different days. What design is this?

• Independent measures

• Repeated measures

• Matched pairs

• Natural experiment

A study tests if caffeine improves memory. One group drinks coffee, the other doesn’t. What’s the main risk with this independent measures design?

• Order effects - practice or fatigue

• Counterbalancing

• Individual differences between groups, such as natural memory ability or caffeine tolerance

• Practice effects

How can a psychologist reduce individual differences in independent measures design?

• Use the same participants in all conditions

• Counterbalance the order

• Use random allocation

• Give everyone coffee

A class completes a memory test in silence, then again with background noise. Half start with silence, half start with noise. What method is used?

• Random sampling

• Random allocation

• Counterbalancing

• Repeated guessing