Independant variable
In an experiment, it is the variable that it controlled and manipulated by the researcher.
Dependent variable
The variable that is measured by the researcher as a result of the manipulation to the IV.
Extraneous variables
These are generally unwanted variables that can have an impact on the relationship between the IV and the DV.
There are two types of extraneous variable: participant variables and situational variables
Participant variables
These relate to individual characteristics of a participant that may impact how they respond
Situational variables
These relate to things in the environment that may impact how each participant responds.
What are the 3 ways to reduce extraneous variables?
1) Standardisation
2) Random allocation
3) Double blind procedure
Standardisation
Keeping parts of the procedure the same so each participant experiences the same procedure.
Random allocation
Participants are randomly allocated to conditions rather than an experimenter choosing.
Double blind procedure
Neither the participants taking the test nor the experimenter know which condition the participants are in.
What are the 4 sampling techniques?
Random sampling
Stratified sampling
Volunteer sampling
Opportunity sampling
Random sampling technique
Every member of a population has an equal chance of being selected.
Strengths of random sampling technique
Weaknesses of random sampling technique
Stratified sampling technique
A technique that ensures subgroups of a target population are proportionately represented in the sample.
Strengths of stratified sampling technique
-Useful if a small subgroup of the target population may be missed.
Weaknesses of stratified sampling technique
Opportunity sampling
Simply selecting those people that are available at the time.
Strengths of opportunity sampling technique
Weaknesses of opportunity sampling technique
Define experimental designs
Experimental designs is how the participants are split into conditions.
Name the 3 types of experimental designs
1) Independent groups design
2) Repeated measures design
3) Matched pairs design
Independent groups design
Participants are split into conditions with each group tested in only one condition of the study.
Strengths of independent groups design
Weaknesses of independent groups design