Experimental Designs

What are Independent Groups?

Participants are completely diffierent in both conditions.

Strengths and Weaknesses of Independent Groups

Strengths - No order effects, lower drop out rate (less time consuming).

Weaknesses - groups may not be well matched (can be fixed by using random allocation, requires a different set of people (harder to recruit people/more expensive).

What are Repeated Measures?

Participants do both conditions (the same people)

Strengths and Weaknesses of Repeated Measures

Strengths - Groups are perfectly matched (same people), requires fewer participants(less time consuming for researcher to recruit people).

Weaknesses - Order effects (might get bored,practice or fatigue).

What are Matched Pairs?

Participants are matched on a characteristic and then split into to conditions (both groups have similar characteristics).

Strengths and Weaknesses of Matched Pairs

Strengths - Control of participant variables (EV)

Weaknesses - Time consuming and may not be possible to completely match both groups.

What is the definition of order effects?

Effects of the repeated measures design, participants get tired (get worse at a task) or get practice (get better at a task).

Can fix using counterbalancing:

Group one does tasks in order AB

Group two does tasks in order BA

What is the defintion of Participant variables?

Difference between the participants (e.g eyesight).

Can fix using random allocation (no bias,e.g picking names out of a hat or using a random generator).