Psychology Research methods 1b:

Opportunity sampling

Opportunity sampling

anyone who is in the nearby area who is willing to take part

Random sampling

a sample that fairly represents a population because each member has an equal chance of inclusion. done by using the lottery method (computer based randomiser).

stratified sampling

reflects the proportions of people in subgroups (designed to be representative). Researcher identifies subgroups (stratas). proportions are then calculated for pps to be selected

Systematic sampling

Every nth member in the target population is selected

Volunteer sampling

self-selected sample often responding to an advert

Advantages of opportunity sampling

quick, convenient, and economical

Advantages of random sampling

less bias, enhances validity, CV/EV distribution

Advantages of stratified sampling

representative sample, higher ecological validity

Advantages of systematic sampling

objective (less researcher bias)

Advantages of volunteer sampling

easy, low input, pps more engaged

Disadvantages of opportunity sampling

potential for researcher bias, unrepresentative

Disadvantages of random sampling

time consuming, difficult, unrepresentative sample

Disadvantages of stratified sampling

time consuming, true representative sample not always possible

Disadvantages of systematic sampling

time consuming

Disadvantages of volunteer sampling

attracts a certain 'type' of pps, potential volunteer bias, ecological validity and demand characteristics could affect the experiment

informed consent

fully informed consent to participate in the research. Can cause issues with validity as pps may change their behaviour

deception

hiding the true aims of the study

Protection from harm

should be protected from psychological + physical harm

privacy/confidentiality

make it all anonymous

4 ethical guidelines

1. informed consent

2. deception

3. protection from harm

4. privacy/confidentiality

how to deal with informed consent

retrospective (ask for consent after the study), presumptive (obtain consent from another group similar to the pps and the pps are told after), prior general (consent before with limited info), right to withdraw data

how to deal with deception

debriefing (at the earliest opportunity without ruining data), right to withdraw/withhold data

Dealing with protection from harm

debrief (pps told all the aims and details after), right to withdraw/withhold data, counselling (options of counselling given afterwards)

dealing with privacy/confidentiality

Maintain anonymity, private data should not be published

ethical issues

results from the rights of pps and the need for valid research clashing

colleagues

must check their ethical practices

BPS code of conduct

quasi-legal document to protect pps based on: respect, competence, responsibility and integrity

ethics committee

weigh up costs (harm to pps) and benefits (value of research) before deciding wether a study should go ahead

social desirability

pps want to present themselves in a positive way