Experimental design (5)

What is experimental design?

How we arrange the PPs (which condition they'll take part in)

What are experimental conditions?

The condition of the study that contains the IV (Can be more than 1)

What's a control condition?

Condition that provides a baseline measure of behaviour

3 types of experimental design?

• Repeated measure

• Independent groups design

• Matched pairs

What is repeated measures?

PPs take part in all conditions of the study

Advantages of repeated measures?

• No pp variables ( person is the same in each condition)

• Fewer PPs needed- less time consuming to find pps

Disadvantages of repeated measures?

• Order effects (Boredom + practice)- reduces validity

• Demand characteristics- may guess the aim of the study

How can we deal with the limitations of repeated measures?(3 ways)

• use 2 tests matched for difficulty

• Counterbalancing

• Standardised

what is independent group design?

Participants only take part in one condition of the experiment

Advantages of independent group design?

• No order effects

• No demand characteristics

Disadvantages of independent group design?

• Participants variables- PPs in each group are different

• More pps needed

ways to deal with limitations of independent groups design?

• randomly allocate PP is to reduce PP variables

• Match pairs design

What's matched pairs design?

Each pp in condition A paired with a pp in condition B based on variables such as IQ. Each matched pair performance is compared

Advantages of matched pairs design?

• less PP variables- matched on a key variable/characteristic- enhances validity

• No order effect

Ways to deal with limitations of matched pairs design? (2)

• Restrict number of variables to match-easier

• Conduct a Pilot study- small scale trial run of actual investigation