Psychology AOS 3 - Research Methods

An aim should

Be short, clear, simple, and explain the purpose of the experiment

Research hypothesis

Testable prediction between two variables, that includes IV, DV, population (focus group, or target audience) and predicted direction of results.

Must be in the past tense!

Controlled experiment

An experiment that successfully controls all variables so only the IV has an affect on the DV

Controlled variable

Variable considered to have affect on DV, so is controlled.

Independent Variable

Variable manipulated (controlled, selected or changed); we want to find its affect on dependent variable.

Dependent Variable

Variable measured for change due to Independent variable

What is operationalising a variable?

Specifying precisely how the variables will be measured or manipulated in a particular controlled experiment. Use data, numbers, and specifics.

The 3 types of research methods

EXPERIMENTAL:

• Experimental methods such as laboratory or field experiments

NON-EXPERIMENTAL:

• Correlational methods such as correlation studies or simulation studies

• Descriptive methods such as observational studies, self-reports (questionnaires and interviews), or case studies.

Experimental vs non-experimental research methods

Experimental involves manipulation of a variable, non-experimental does not.

Correlation studies

An investigation of the relationship between variables without manipulation. Usually involves looking at previously-gathered statistics.

E.g. Researcher obtains pre-existing temperature data and occurrence of violent crimes data to measure relationship between them.

PROS: Provides more real world application

CONS: No 'why', limits internal validity

Descriptive methods

Self report, observation without manipulation, case study into someone's actions or an event.

PROS: Cheap, easy

CONS: People can lie or hide things

Cross-sectional method

Analyses data from specific point in time, across multiple subgroups. No manipulation occurs.

E.g. Psychologist collects university student's data across different majors to compare difference between academic stress and coping strategies.

PROS: Inexpensive and easy

CONS: No context of what happened before, can't show 'why' of relationship

Longitudinal study

Repeated observations of same people over long period of time.

E.g. Researcher studies children from when they're 5 to 18, seeing how attachment style impacts later emotional development.

PROS: High accuracy

CONS: Time consuming, costly, and people may drop out

Population

Also called target population. Entire group of research interest which researcher wants to generalise results onto.

Sample

Subset of population selected for research purposes

Sampling techniques

Random, Stratified, Convenience

Random sampling

Every member of population has equal opportunity

PROS: Reduces bias and fairly representative

CONS: May be time consuming or not very representative.

Stratified sampling

Selecting sample that accurately represents specific subgroups.

PROS: Produces most representative sample

CONS: Can be time-consuming and expensive, demanding on researcher to select appropriate sample

Convenience sampling

Sample comprises individuals who are readily available.

PROS: Time & cost effective

CONS: Unrepresentative sample

Extraneous variables

Variables other than IV that MAY change DV and affect results

Confounding variables

Variables other than IV that have had an affect on DV, but it changes with/at same time as IV so experimenter can't identify if the IV or CV produced the change.

Extraneous vs confounding variables

Extraneous may affect DV, confounding has affected DV.

Ethical concepts

BENEFICENCE: Maximise benefits, minimise risk.

INTEGRITY: Search for knowledge and reporting honestly, allowing scrutiny, and contributing to public understanding

JUSTICE: Fair consideration of competing claims, no unfair burden on one group or access to benefits.

NON-MALEFICENCE: Avoiding causing harm

RESPECT: Considering living things' value, decision making capacity, welfare, customs, and protecting those whose ability to decide has diminished

Ethical guidelines

CONFIDENTIALITY: Privacy and anonymity of information

DEBRIEFING: Participants leave knowing aim, results and conclusions

INFORMED CONSENT: Understand experiment purpose and risks before agreeing

DECEPTION: Only permissible if knowledge will affect participant's actions + therefore results.

VOLUNTARY PARTICIPATION: No coercion to participate

WITHDRAWAL RIGHTS: Participants can leave with no penalty at any time during or after

Reliability

Extent to which a measure produces consistent results

Validity

Either internal or external. Extent to which a measure accurately measures what it is meant to be measuring. Results represent true findings in similar people in a population.

Internal validity

How well study was conducted.

Extent investigation investigate what it set out to or said it would investigate. Investigation will be free from flaws, and its results will be due to investigation not other factors

External validity

Applicability of results.

Extent study's results can be applied to beyond sample that made them.

Generalisation

Decision on how widely applicable the results are.