RM- experimental control

Experimental control

Extent of which we know the independent variable is affecting the dependent variable. To do this we need to control extraneous variables

What are the 4 ways to achieve experimental control

Random allocation

Randomization

Standardization

Counterbalancing

Random allocation

Giving an equal chance to all participants to be in two or more groups.

How to do random allocation

Hat method-

Put all participants names onto separate pieces of paper and screw them up

Put into a hat

Randomly pick half the names to be put into condition A, rest will be placed in condition B

Counterbalancing

Advanced form of repeated measures. Needed as condition B is affected by order or practice effect. It still exists but is spread evenly

Standardisation

Keeping the experience the same for all participants with only the independent variable that changes

Standardization results

If results are different, the only thing that caused it is the independent variables effect on the dependent variable

Why is standardization important

Increases control and validity, reducing extraneous variables affecting the dependent variable

Randomization

Giving all participants the same questions in a randomized order so order effect doesnt affect the same questions