Means by which explanations are tested

Research method using random allocation of participants and the manipulation of variables to determine cause and effect

Factor manipulated by researchers in an investigation

Factor measured by researchers in an investigation

Process of defining variables into measurable factors

Variables other than the IV that might affect the DV

Uncontrolled extraneous variables that negatively affect results

Features of research which allow participants to work out aim of study and change behaviour accordingly

Researcher effects where researchers features influence participants’ responses

Experiment conducted in controlled environment allowing establishment of causality

Experement conducted in naturalistic environement where researchers manipulate the IV

Experiment where IV varies naturally

Experiment where researcher is unable to freely manipulate IV or randomly allocate participants to different conditions

Surveilance and recording of naturally occuring events

Dividing target behaviours into subsets of behaviours through use of coding systems

Where observers consistently code behaviour in the same way

Participants giving info about themselves without researcher influence

Self-report method where participants record their own answers to a pre-set list of questions

Self-report technique where participants answer questions in face-to-face situations

One-tailed hypothesis

Two-tailed hypothesis

Why a study is taking place/what’s being studied/trying to achieve

If results support null hypothesis, researchers origional idea might be incorrect. Whatever happens in stud, researcher needs to be able to accept a hypothesis at end of study

Precise, testable prediction of what is expected to happen

Experimental/alternative

Null

Hypothesis of no difference. Predicts IV won’t affect DV and that differences in results will be due to chance factors, not manipulation of IV and therefore no significant

Predicts that differences in DV will be beyond boundaries of chance (will occur as result of manipulation of IV)

Differences beyond the boundaries of chance

Statistical tests

Directional

Non-directional

Predicts direction of results

Predicts that there will be a difference but doesn’t predict direction of results

When previous research suggests results will go in one direction or when replicating previous study that also used directional hypothesis

Target group with psychologist is interested in studying

When each member of population has equal chance of being selected. Placing all names into a hat and draw required number of names/use random generator

Unbiased selection thus more likely representative

Results can be generalised

Impractical - time-consuming

Not representative - could all be females selected thus not representative and can’t be generalised

Selecting participants who are available and willing to take part. Ask people in street who are passing

Easy to carry out

Natural experiments - no contol over who is studied

Quick

Unrepresentative - easy to obtain biased sample by only using those around at the time

Self-selection - can refuse to take part

People volunteer to take part, often by replying to adverts

Easy to do, little effort

Less chance of ‘screw you’ phenomenon as want to take part so less likely to sabotage

Unrepresentative - biased so can’t be generalised

Demand characteristics - increases as egar to take part

Taking every nth person from the list to take sample. Involves calculating size of population and assessing size of sample to calculate sampling interval