Controlling EVs Through Experimental Design & Internal Validity: RM Flashcards
What are Experimental Controls?
Procedures used by researchers in an experiment that minimise the impact of EVs on the internal validity.
What are Independent Groups?
Different participants for each condition with no related variables between the people in each condition.
What are Repeated Measures?
When the same participants are in both conditions.
What are Matched Pairs?
The participants in each condition are different however they relate in at least one way.
Strength: Independent Groups.
Controls Order Effects. (No conditions will be repeated for any participants)
Strength: Repeated Measures
Controls any Participant Variables. (No individual differences between the participants, as it is the same person doing it). It strengthens the experiments internal validity.
Strength: Matched Pairs
It’s ability to control for participant EVs. Reducing the differences between the individuals by matching certain variables.
Limitation: repeated measures.
It is vulnerable to order effects. As the experiment is repeated this means one will always be completed before the other, meaning the conditions could influence the
dependent variable. ( eg. Getting bored or having more practice )
Limitations: independent groups. E.g?
It is vulnerable to participant EVs. The participant in each condition are different therefore can undermine the internal validity and cause the EVs to become confounding. (Eg. age, gender or intelligence).
Limitations: matched pairs.
It doesn’t offer the perfect control for participant variables. Although the participants are matched due to similarities, it doesn’t mean they are matched in all ways. (Eg. Same age but different IQ). Therefore the participant EVs can become more confounding.
What is Standardization? Controls?
Same procedures, same environment, same instructions and processes. Controls Situational and Investigator effects.
What is Random Allocation? Controls?
The process of randomly allocating participants to conditions.( e.g. the hat method ). Controls Participant EVs.
What is Randomization? Controls?
The process of using a random process to decide the allocation of ANYTHING within the research. Controls Investigator effects and situational variables.
What is Counterbalancing?
The researcher preventing the participants from completing the same condition twice. Controls repeated measures.
What is a Single-Blind procedure? Controls?
The researcher doesn’t tell the participants the aim or what is happening in the conditions. Controls Demand Characteristics.
