2.2.1-2.2.10 Experiments Flashcards
‘Experiment’ definition
A scientific procedure undertaken to test a hypothesis in order to demonstrate causal relationships
Outline what a ‘Lab Experiment’ is
-experiment where the researcher directly manipulates the IV to see the effect on the DV
-occurs in a controlled, artificial environment (control noise, space, temp)
-participants sign up
Outline what a ‘Field Experiment’ is
-experiment where the researcher directly manipulates the IV to see the effect on the DV
-occurs in a natural environment such as a school or a shopping centre
-experimenter goes to participants
Weaknesses of a Lab Experiment
-expensive to conduct
-participants are likely to guess aim and therefore demonstrate desired characteristics
-difficult to recruit participants
-time consuming to conduct
-low in external validity
Strengths of a Lab Experiment
-very scientific as it occurs in a controlled environment
-high repeatability and reliability as the same procedure is usually used for all participants
-participants can usually always give informed consent
-groups can be randomally allocated (no experimenter bias)
-high in internal validity (control of extraneous variables)
Weaknesses of a Field Experiment
-does not have full control over variables so not easy to repeat
-may not be able to gain informed consent
-sample could be unreppresentative
-low internal validity
Strengths of a Field Experiment
-shows natural behaviour but is also controlled
-high generalisability
-easy to gain participants
-participants won’t guess aim
-high in ecological validity
‘Hypothesis’ Definition
A statement that predicts the outcome of the results
‘Opeerationalisation’ Definition
Making the variable clear and precise by giving detail about the study
‘Experimental Group/Condition’ definition
The group who experiences the manipulated IV to see if it has any effect
‘Control Group/Condition’
the group that experiences no manipulation in IV, so it acts as a baseline for comparison
‘Experimental/Alternative Hypothesis’ definition
Hypothesis that states a relationship or difference between variables
‘Null Hypothesis’ definition
States that there is no relationship or difference between variables
‘Directional/One tailed Hypothesis’ definition
States the direction of the results thats expected (eg. higher, worse)
‘Non-Directional/Two Tailed Hypothesis’ definition
Does not predict the direction of results
‘Experimental Design’ definition
how participants are allocated to different groups in an experiment
‘Independent Measures’ definition
when different participants are used in each condition of the IV
Evaluate Independent Measures
Strengths: each participant takes part in 1 condition so therefore won’t guess the aim
Weaknesses: individual differences affect results, large group sizes are requires
‘Repeated Measures’ definition
when the same participants take part in each condition of the IV
Evaluate Repeated Measures
Strengths: eliminates individual differences, can have a small sample
Weaknesses: could guess the aim of research, could demonstrate order effects
‘Matched Pairs’ definition
pairs of participants are matched across groups in terms of key variables
Evaluate Matched Pairs
Strengths: overcomes individual differences
Weaknesses: difficult to find matched pairs, time consuming