psychology - research methods

unfinished

What is a hypothesis

A testable statement that states relationship between variables

What is a confounding variable

When the extraneous variable hasn’t been properly controlled and it effects the DV

How to limit confounding variables

• standardisation → using same procedures for all ppt

• randomisation → controls bias

What are the experimental designs

• repeated measures

• independent groups

• matched pairs

What are the order effects of repeated measures

• boredom → ppt perform worse at end

• fatigue → ppt perform worse at end

• practice → ppt get better at task

How do you reduce order effects?

Counterbalancing → half the ppt do condition A then B, then other half to B then A

What is random sampling

• ppt have equal chance of being selected

• ✅no researcher bias

• ❌unrepresentative

What is systematic sampling

• every nth ppt is selected

• ✅no researcher bias

What is stratified sampling

• sample represents target population

• ✅representative, no researcher bias

• ❌doesn’t reflect individual differences

What is volunteer sampling

• ppt volunteer to be in study

• ✅no researcher bias

• ❌volunteer bias → all ppt might have certain trait e.g outgoing → extraneous variable

What is opportunity sampling

• researcher selects whoever is available

• ✅convenient

• ❌researcher bias

What is a pilot study

Small scale investigation that takes place before real investigation. Checks if materials are reliable and valid

What are limitations of questionnaires?

• lack validity

• social desirability

• demand characteristics

• difficult to write questions that aren’t leading or unclear (need a pilot study)