Research and Experimental Designs
Experimental Design= name given to a research design when used in an experiment
Types of Research and Experimental Designs
1. Independent Measures Design:
Participants are split No order effects= ● More participants are Participants can
into groups and each participants only take needed be randomly
group is tested in only part in one condition ● There may be allocated
one condition individual differences
2. Repeated Measures Design:
Participants are used ● Fewer participants ● Demand Order effects need to
in all conditions are needed characteristics be controlled using
● No individual are more likely 1. Counterbalancing
differences between ● Order effects 2. Randomisation
conditions
3. Matched pairs design:
Uses different people Fair Comparisons can Time consuming to
in each condition= but be made between the match all
matching them for groups participants/ Not all
likeness on important characteristics can be
characteristics equally matched
Definition Strengths Weaknesses Controlling Problems
Validity and Reliability
Dartboard Analogy= If the goal of the research is the bullseye:
Reliability= how consistent we are/ consistency, regardless of,
Validity= how close we get to the bullseye
Reliability:
● The extent to how similar the results would be if the study is replicated
● Consistency of an outcome or result= Same result is found over and over again
● If standardised procedure= not used then there can be variability in the procedure= results in
unreliable findings/ should be the same method and task for all, no extraneous variables
● Inter-rater Reliability: when two or more researchers agree on what they see= increases the reliability
Reliability in:
● Sampling Methods: leads to a biased sample then the outcome= may not be relied upon to occur again
as it could differ when replicated
Experimental Design= name given to a research design when used in an experiment
Types of Research and Experimental Designs
1. Independent Measures Design:
Participants are split No order effects= ● More participants are Participants can
into groups and each participants only take needed be randomly
group is tested in only part in one condition ● There may be allocated
one condition individual differences
2. Repeated Measures Design:
Participants are used ● Fewer participants ● Demand Order effects need to
in all conditions are needed characteristics be controlled using
● No individual are more likely 1. Counterbalancing
differences between ● Order effects 2. Randomisation
conditions
3. Matched pairs design:
Uses different people Fair Comparisons can Time consuming to
in each condition= but be made between the match all
matching them for groups participants/ Not all
likeness on important characteristics can be
characteristics equally matched
Definition Strengths Weaknesses Controlling Problems
Validity and Reliability
Dartboard Analogy= If the goal of the research is the bullseye:
Reliability= how consistent we are/ consistency, regardless of,
Validity= how close we get to the bullseye
Reliability:
● The extent to how similar the results would be if the study is replicated
● Consistency of an outcome or result= Same result is found over and over again
● If standardised procedure= not used then there can be variability in the procedure= results in
unreliable findings/ should be the same method and task for all, no extraneous variables
● Inter-rater Reliability: when two or more researchers agree on what they see= increases the reliability
Reliability in:
● Sampling Methods: leads to a biased sample then the outcome= may not be relied upon to occur again
as it could differ when replicated
