Research Methods
, Research Methods
Sampling Methods:
Random Sampling: Everyone in the target population has an equal chance of being chosen.
More likely to be representative.
Time-consuming.
Opportunity Sampling: Using anyone who is available from the target population.
Quick and easy.
Unlikely to be representative due to researcher/selector bias.
Stratified: Identify subgroups, then choose randomly from each in proportion.
All subgroups represented, therefore it is representative.
Very time-consuming.
Systematic: A system of choosing, such as every 5th name on a list.
Fairly simple, avoids researcher bias.
Sample may not be representative.
, Research Methods
The Experiment:
Laboratory Experiment: Conducted in a carefully controlled environment.
High control, can infer cause and effect, ethical - participants know they are taking part.
Artificial situation, less ecological validity.
Field Experiment: Takes place in a natural environment.
Natural behaviour and environment, greater ecological validity.
Less ethical - participants may not know they are taking part.
Quasi Experiment: No random allocation to conditions, a naturally occurring independent variable.
Allows for investigation using pre-existing variables.
No random allocation/direct manipulation, so less confidence in inferring cause and effect.
, Research Methods
Sampling Methods:
Random Sampling: Everyone in the target population has an equal chance of being chosen.
More likely to be representative.
Time-consuming.
Opportunity Sampling: Using anyone who is available from the target population.
Quick and easy.
Unlikely to be representative due to researcher/selector bias.
Stratified: Identify subgroups, then choose randomly from each in proportion.
All subgroups represented, therefore it is representative.
Very time-consuming.
Systematic: A system of choosing, such as every 5th name on a list.
Fairly simple, avoids researcher bias.
Sample may not be representative.
, Research Methods
The Experiment:
Laboratory Experiment: Conducted in a carefully controlled environment.
High control, can infer cause and effect, ethical - participants know they are taking part.
Artificial situation, less ecological validity.
Field Experiment: Takes place in a natural environment.
Natural behaviour and environment, greater ecological validity.
Less ethical - participants may not know they are taking part.
Quasi Experiment: No random allocation to conditions, a naturally occurring independent variable.
Allows for investigation using pre-existing variables.
No random allocation/direct manipulation, so less confidence in inferring cause and effect.
