psychology research methodss

Situational variable

variables present in the environment that might effect the results of the experiment. e.g temperature,noise,light levels

Participant variable

when a participants mood,ability,nationality,etc. might effect the results

order effects

when the particpants worsen or improve in the second condition because they became tired or have parcticed.

standardised procedure

all parts of the procedure are kept the same. So every participant experiences the same condition

investigator effects

when the researcher unintentionally gives away the aims of the investigation

demand characteristics

when the participants alter their behavior because they discovered the aims of the study.

counterbalncing

half of the participants experience condition A then B whilst the other half experience condition B then A. So that order effects cancel out.

Random allocation or randomisation

participants are randomly assigned to a condition

single blind technique

the true aims of the investigation are kept hidden from the participants

double blind technique

when the aims of the investigation is kept from both the investigators and the participants.

Questionnaires

Pre-written questions handed to participants which allow them to directly provide information about themselves. ADVANTAGES: highly replicable,time and cost efficient, investigator effects reduced(investigator not present)DISADVANTAGES : people may modify answers to show them selves in best light, participant samples biased, participants unable to ask for help

interviews

allow participants to directly provide information about themselves.Pre-written set of questions. all participants asked the same questions.ADVANTAGES: more appropriate when dealing with sensitive or complex issues, misunderstandings may be followed up immediately. DISADVANTAGES:Participants modify answers to bring themsleves into light, interviewer effects(low inter rater reliability), time consuming.

Field experiment

same as laboratory experiment but in a real life setting.ADVANTAGES-Participants may act more naturally than in laboratory,demand characteristics reduced(participants unaware they are taking part),determine cause and effect in most situations.DISADVANTAGES-researchers control over enviroment reduces validity,partcipants if unaware they are taking part may become distressed by manipulation of independent variablr,population validity reduced(reasercher no control over participants)

Laboratory experiment

Take place in laboratory in a university. Directly manipulated by researcher.ADVANTAGES-cause and effect can be inferred with reasonable confidence,easy to replicate,specialist equipemnt can be used to deepen understanding.DISADVANTAGES-participants may not demonstrate real life behavior,demand characteristicts, ethical rules limit researchers

Natural experiment

Reasercher does not manipulate independent variable(it is naturally occuring).ADVANTAGES-can study unethical or impractical studies if studied in a different way,researcher able to study real problems and situations,demand characteristics reduced.DISADVANTAGES-reasercher has no control over enviroment,ethical guidelines of consent may not be met,often impossible to repicate

correlations

Relation ship between two variables.ADVANTAGES-use pre-existing data(time and cost effective)Study impractical or unethical studies if studied in different way,precise method(tell researchers exact strength)DISADVANTAGES-impossible to establish cause and effect, inaccurate conclusions may infer something else,only measure linear relationships(clear)

case study

In depth study of a single person and focus on one aspect of their behaviour.ADVANTAGES-allow to study impractical studies,suggest new hypothesis for existing studies,complex interactions can be studiedDISADVANTAGES-hard to generalise results,ethical issues,interpretation of researcher might be different or biased to what is actually happening

observation

behaviour is watched and recorded. Structured observation- decide what they record. ADVANTAGES-participants act naturally,allow researchers to study impractical or unethical studies if studied in different way,investigating new areas help produce hypothesis. DISADVANTAGES-If participants know they’re observed they can alter behavior,ethical issues(participants dont know they are being observed),Low reliability(observers dissagree on judgment)

Random sampling

picked out of a hat. ADVANTAGES-not a biased sample,cost and time effective, equal chance.DISADVANTAGES-target population may not be represented,participnats may not want to take part.

opportunity sampling

using participants that are ready to use.ADVANTAGES- ethical,time and cost efffective.DISADVANTAGES-biased sample not all of target population is represented,not an equal opprotunity.

stratified sampling

identifies sub groups of population.ADVANTAGES-all of target population represented,most reliable results. DISADVANTAGES- time consuming,people can refuse, invalid conclusions

self selected (volunteer) sampling

asking participants to take part.ADVANTAGES-most ethical,minimal effort,possible to recruit target populationDISADVANTAGES-target population may not be represnented

Repeated measures

Participant experience all conditions.fewer people needed. order effect affect results. Participnat characteristics(extraneous variable) kept constant

Independant measures

Each group experiences only one condition. Participant characteristics may affect results. More participants are needed

Matched pairs

two groups of participants are matched on key characteristics. Time consuming.Not possible to match all characteristics.More participants are needed.

experimental designs definition

three different ways of deciding which participants are in which condition.

Independent measures

repeated measures

Matched psirs

reliability

when something can be repeated multiple times and you get the same result.( consistency of an outcome)

internal validity(validity)

how confident are we that the test measures what it intends to.

ecological validity

how generalisable the findings are to the real world.(situations or setting typical of everyday life.)

population validity

how generalisable the findings are to a larger group of people(target population)

Protection from harm

Participants should be no worse off when they leave an experiment as to when they arrived.

informed consent

letting participants know what they are going to have to do in the study so their consent is 100% valid

deception

Participants should know all the information about the experiment. Only if something might affect the results some things can be kept a secret

right to withdraw

participants are able to withdraw at any moment even after the experiment finished

debrief

if consent cannot be obtained participants must be fully debriefed afterwards. The participants have the right to withdraw their information

Qualitative data

mainly in words

Quantitive data

numerical

primary data

direct for a specific research

secondary data

already been collected

Bar chart

data in categories

histogram

groups numbers into ranges

scatter graphs

used for correlation data to show relation ship.

independent variable

the variable the researcher manipulates

x-axis

dependent variable

the variable the researcher measures

y-axis

confounding variable

when a extraneous variable isn’t controlled and impacts dependent variable

Null vs Alternative hypothesis

Null: a hypothesis that predicts no significant difference or correlation in the results of a study.

Alternative hypothesis : a testable statement that predicts a significant difference or correlation.

non directional- there will be a difference but doesn’t suggest direction e.g a gender difference

directional- states the direction of the difference or correlation. e.g males higher than female