Conducting Research Flashcards
Three Experimental Designs
Repeated Measures
Independent Groups
Matched Pairs
Define Repeated Measures
The Same Participants are used in both conditions
Define Independent groups
Participants are randomly allocated to different groups which represent different conditions
Define Matched Pairs
Pairs Of Participants are closely matched and are then randomly allocated to one of the experimental conditions.
Strengths Of Repeated Measures
As the same participants are used in each condition, participant variables (i.e., individual differences) are reduced.
Fewer people are needed as they take part in all conditions (i.e. saves time).
Weakness Of Repeated Measures
There may be order effects.
Performance in the second condition may be better because the participants know what to do (i.e. practice effect).
Or their performance might be worse in the second condition because they are tired (i.e., fatigue effect).
Strength Of Independent Groups
Avoids order effects (such as practice or fatigue) as people participate in one condition only.
If a person is involved in several conditions, they may become bored, tired and fed up by the time they come to the second condition, or becoming wise to the requirements of the experiment!
Weakness Of Independent Groups
More people are needed than with the repeated measures design
Differences between participants in the groups may affect results, for example; variations in age, gender or social background. These differences are known as participant variables
Strengths Of Matched Pairs
Reduces participant variables because the researcher has tried to pair up the participants so that each condition has people with similar abilities and characteristics.
Avoids order effects, and so counterbalancing is not necessary.
Weakness of Matched Pairs
Very time-consuming trying to find closely matched pairs.
Impossible to match people exactly, unless identical twins!
Define Order Effect
Order effects refer to the order of the conditions having an effect on the participants’ behavior.
Define Practice Effect
Practice effects are influences on test results when a test is taken more than once.
Practice can increase your overall score
Define Fatigue Effect
Results from short-term sleep loss or from short periods of heavy physical or mental work
Define Counter Balancing
is a type of experimental design in which all possible orders of presenting the variables are included.
5 Sampling Techniques
Random Sampling Stratified Sampling Opportunity Sample Systematic Sampling Volunteer Sample
Define Random Sampling
Everyone in a entire target population has an equal chance of being selected
Define Stratified Sampling
Researcher identifies the different types of people that make up the target population and works out the proportions needed for them to be represented
Define Opportunity Sampling
Using people from a target population available at the time and willing to take part
Define Systematic Sampling
Chooses subjects in a systematic (Orderly/Logical) way from the target population like every nth participants on the list of names