G544 - Types of experiments

What is it? An experiment which is conducted in highly controlled conditions where the independent variable is carefully manipulated and controlled, with the effect on the DV also being isolated to identify a causal effect. Usually in a laboratory setting. 

Strengths: High levels of control, highly objective, high control over extraneous variables, easy to establish cause and effect, highly replicable.

Weaknesses:  Low in ecological validity as conditions are artificial, difficult to generalise results to the target population, demand characteristics are present.

What is it? An experiment conducted in the participant’s usual environment in a real life setting in real time. 

Strengths: High in ecological validity as natural setting, can be generalised well to target population, reduced demand characteristics.

Weaknesses: Reduced control over extreneous variables, difficult to establish cause and effect, difficult to replicate, ethical issues in terms of consent and right to withdraw.

What is it? An experiment where the independent variable is naturally occurring and not manipulated.

Strengths: Low in control, high in ecological validity, can be generalised to the population that falls under the naturally occurring variable. 

Weaknesses: Costly and time-consuming to gather a sample as IV must be naturally occuring, samples are small and limited, small sample may not be representative of the target population.