research methods

independent variable

variable that is manipulated by the researcher

dependent variable

variable that is measured by the researcher

extraneous variable

variable that has an impact on relationship between IV and DV (eg. age, gender..)

participant variables

characteristics of individuals that may impact how he or she responds in an experiment

situational variables

things in the environment that impact how participants responds

how to reduce extraneous variables

1. standardisation: keeping parts of procedure the same

2. random allocation: participants picked out of a hat to allocate to condition rather than experimenter choosing

3. single/double blind technique: people conducting the tests don’t know the condition that the participant is in

sampling techniques

1. random

2. stratified

3. volunteer

4. opportunity

random sampling

every member of a population has an equal chance of being selected

✅: unbiased representative sample, generalizable

❌: time-consuming, not guareenteed representative

stratified sampling

dividing the target population into important subcategories and selecting members as they occur in the population

✅: sample representative of the target population

❌: time consuming

volunteer sampling

individuals who have self-selected to participate in a study

✅: convenient, ethical, minimal effort

❌: unrepresentative

opportunity sampling

simply selecting those people that are available at the time

✅: quick and convenient, economical, saves time

❌: unrepresentative

experimental designs

1. independent group design

2. repeated measures design

3. matches pairs design

independent group design

there are different participants in each condition

✅: removes order effects as participants only complete one condition so the results are more valid

❌: individual differences reduces validity, more participants needed reduce

repeated measures design

same participants used in all conditions

✅ : compares same participants → changes are real so more valid, no need lots of participants

❌: order effect, practice effect, boredom

matches pairs design

different participants in different conditions who are matched on characteristics

✅ : controls individual differences which increases validity

❌: difficult and time consuming

hypothesis, null hypothesis and alternative hypothesis

hypothesis: testable statement of what the researchers predict will be the outcome of the study

null hypothesis: states that there is no relationship between the two variables

alternative hypothesis: indicates that there is a relationship or effect between the variables being studied.

experiments

1. laboratory experiments

2. field experiments

3. natural experiments

laboratory experiments

takes place in controlled environment such as lab, researcher deliberately manipulates the IV while maintaining strict control over the extraneous variables

✅: reliability (easily replicable), high control of extraneous variables

❌: lack ecological validity, likely to have demand characteristics

field experiments

same as the lab experiment except the environment is swapped for real life environment like a school

✅: high ecological validity,

❌: extraneous variables are more likely to comfound the results and reduce validity, more time consuming and expensive

natural experiments

the change in the experiment is not brought by the researcher, it would occur whether the experimenter was interested in it or not

✅: high ecological validity, high generalisability

❌: confounding variables,

self report methods

1. interviews

2. questionnaire

interviews

structured: premade questions

unstructured: interviewer makes up the questions on the spot

semi structured: some questionsa re made before and some are made up on the spot

strengths of interviews

structured: lots of info quickly, reliable

unstructured: indepth information (validity)

semistructured: freeflowing convo, indpeth information

weaknesses of interviews

structured: superficial information that decreases validity

unstructured: time consuming

semistructured: needs training to encourage a free flowing conversation

questionaires

predesigned questions

qualitative data: explain why you enjoy psychology

quantitative data: do you like psychology

✅ : cheap, ethical

❌: participants may not answer truthfully, not respond to all questions (validity)

observations

1. participant observation: The observer takes part in an activity to be observed

2. nonparticipant observation: The observer does not take part in the activity to be observed

3. covert observation: observation is a secret

4. overt observation: participant knows they’re being observed

5. naturalistic observation: observation in a natural setting

6. structured observation: observation is at an event staged by observers to see what happens

reliability

whether the research can be replicated, is the results consistent

validity

if the study reflects the truth

case studies

in-depth investigations of a single individual, group, or event, providing detailed insights and understanding.

✅: rich information (validity), high ecological validity

❌:time consuming, hard to generalise

ethics

consent, debrief, confidential, deception, withdraw, protection from harm