Unit 1 - Research Methods Flashcards
Dependent variable
The variable that is measured by an experimenter
Extraneous variables
Variables other than the DV that should be controlled, could have an effect on the performance on the day.
(Only control them if you already know what they are)
Confounding variables
An extraneous variable that has not been controlled which could invalidate results.
Operationalisation
Putting variables into measurable forms
Lab experiment
The independent variable is manipulated by the experimenter in attempt to produce a change in the dependent variable. All other extraneous variables are controlled.
- There is high validity as all extraneous variables are controlled so it’s easy to infer cause and effect,
- however low ecological validity as conditions are very artificial.
Field experiment
The independent variable is manipulated by the experimenter. Takes place in the participants natural environment.
- Higher ecological validity (than lab experiment)
- lower control of extraneous variables- less likely for low internal validity.
Natural experiment
The independent variable is naturally occurring and takes place in a natural environment.
- High ecological validity as more relative to the real world and realistic behaviours but
- low internal validity as low control of extraneous variables makes it hard to determine cause and effect.
Ecological validity
A specific type of external validity. Refers to whether results can be generalised outside of the study to different environments and situations.
Demand characteristics
When participants pick up on cues to the aim of the study and subsequently subconsciously alter their behaviour to fit the aim.
Reliability
The consistency of results
Social desirability bias
Participants desirability that they want to be seen in the best light so may answer the question how they think it should be answered. (not necessarily true to them)
Target population
The total group of individuals from which the sample might be drawn.
Sample population
A small selection of a group of people from a larger population.
Random sampling
When every member of the target population has an equal chance of being selected. e.g. picking names out of a hat.
- Unbiased and representative
- however time consuming and impractical.
Opportunity sampling
Selecting participants due to the fact they’re available and in the right place at the right time.
- This sampling method is quick, economical and convenient
- however often unrepresentative and bias.
Volunteer sampling
Individuals (volunteers) who have determined their involvement in the study.
- This sampling method is convenient and ethical,
- however unrepresentative as volunteers are often different from the rest of the population. i.e. more helpful, intelligent, and outgoing.
Biased sample
If the sample isn’t representative of the rest of the population.
Independent group design
When different participants are used in 2 conditions
AD: can compare the 2 groups, no order effects
DIS: need more people, individual differences
Repeated measures design
When the same participants are used in both conditions.
AD: require fewer participants
DIS: order effects
Matched pairs design
When different but similar participants are used in the two conditions. Participants are matched on individual characteristics e.g. intelligence.
AD: reduces participant variables
DIS: harder to find the participants