Designing Psychological Investigations

Experiments

• IV varied to see the effects on the DV.
• Lab Experiments- high on internal validity low on external validity.
• Field Experiments- more natural enviroment but had more issues of control than a Lad study.
• Natural Experiment- uses naturally occuring IVs but cannot conclude causality in these studies.
• Experimental designs- Idependant designs, Matched pairs, repeated measures.

Observational Studies

• Observing through behavioural categories.
• Sampling methods- time and event sampling
• Open to subjective bias- observations affected by expectations.

Correlational Analysis

• Concerned with relationship between 2 variables.
• Does not demonstrate causality
• Other variables may influence any measure relationship

Self-Report Methods

• Questionnaires and interveiws
• Structured interviews- more easily repeated.
• Unstructured interviews- questions that evolve are dependant on answers given.
• May involve open (respondent provides own answers) or closed (respondant chooses specific answer) questions.
• Main problem- social desirability bias.

Case Studies

• Detailed study of individual institution or event.
• Generally longitudinal, following individual or group over time.
• Allows study of complex interaction of many variables.
• Difficult to generalise from specific cases.

Reliability

• Experimental research- allows replication of study.
• Observations- inter-observer reliability can be improved through training.
• Self-report- internal reliability (split-half) and external reliability (test-retest)

Validity

• Internal validity- does study test what it was intended to test?
• External validity- can results be generalised to other situations and people?
• Lab experiments not necessarily low in external validity.
• If low in mundane realism, reduces generalisability of findings.
• In observations, internal validity affected by observer bias.
• Self-report techniques issues of face anc concurrent validity.

Sampling Techniques

• Opportunity- most easily available participants.
• Volunteer- e.g through advert, but subject to bias.
• Random- all members of target population must have equal chance of selection.
• Stratified and quota- different subgroups within sample, leads to more representative sample.
• Snowball- researcher directed to other similar potential participants

Ethical Issues with humans

• Informed consent and deception.
• Harm- what constitutes too much?

Code of Conduct

• Respect for worth and dignity of participants.
• Right to privacy, confidentiality, informed consent and right ot withdraw.
• Intentional deception only acceptable in some circumstances.
• Competence- retaining high standards
• Protection from harm and debreifing
• Integrity- being honest and accurate in reporting.
• Use of ethical guidlines in conjuction with ethical committees.
• Socially sensitive research- potential social consequences for participants.

Ethical issues with non-humans

• Reasons for animal use- offer opportunity for greater control and objectivity; cant use humans; physiological similarities.
• Moral issues- sentience (experience pain and emotions)
• Specieism- form of discrimination against non-human species.
• Animal rights- no animal research is acceptable (Regan 1984)
• Do animals have rights if they have no responsibilities?
• Animal research subject to strict legislation (Animals act; BPS guidlines)
• The 3 Rs- Reduction, Replacement, Refinement.