Experimental design

Question 1

What are independent measures ?

Answer 1

Different ppts are used in each condition of the IV
One group used for one condition and another for a different one.

Avoids order effects - practice/tiredness

Prevents demand characteristics - harder to figure out aims.

Negative - more participants needed - time consuming - less cost effective

Question 2

What are repeated measures ?

Answer 2

Same ppts take part in each condition of the IV
Avoids participant variables - (individual differences) as same ppts used for all of the conditions.

Can be order effects - Practice (remember study so do better second time) - tiredness

Can use counterbalancing to prevent order effects - Present different conditions in different orders.

Question 3

What are matched pairs ?

Answer 3

Pairs of participants are matched in terms of key variables (gender/age/health status)
One member of the pair does each condition.

Reduces participant variables
Avoids order effects

Can’t perfectly match 2 people
Time consuming to find closely matched pairs
If one person drops out you lose 2 peoples data.