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 participants worsen or improve in the second condition because they became tired or have practiced.

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.

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, participants may not want to take part.

opportunity sampling

• using participants that are ready to use.

• ADVANTAGES - ethical, time and cost effective.

• DISADVANTAGES - biased sample not all of target population is represented, not an equal opportunity.

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 population

• DISADVANTAGES- target population may not be represented

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

lab experiment description

conducted in a controlled environment where the researcher manipulates the IV and observers its effect on the DV.

Lab experiment AO1 points

• allow researchers to have strict control of extraneous variables

• Low ecological validity due to artificial setting

• sampling can be unrepresentative if the sample is biased or has small numbers

• can be easily replicated to test for reliability due to having standardised procedures

Lab experiment AO3 points

• controlled task → low task validity as it may not be an everyday activity for participants

• Artificiality → increase demand characteristics as participants know they are being studied → may not reflect natural human behaviour

• high control over extraneous variables → internal validity

• Test-retest replication of study due to standardised procedure increases reliability of findings

Field experiment description

conducted in a natural setting where the IV is manipulated and the DV is measured

Field experiment AO1 points

• can take place in a realistic environment that participants would be familiar with

• Researchers manipulate the IV and conditions that the participants experience

• there is a DV that is measured by the researcher to test the impact of the IV

• researchers are not always able to control extraneous variables (e.g situational)

Field experiment AO3 points

• not artificial environment → higher ecological validity

• manipulate IV → test specific variables to establish cause and effect conclusions

• task may lack mundane realism if artificial → reduces validity of findings

• extraneous variables can reduce the validity of the results as there may be other influences other than the IV

Natural experiment description

observing naturally occurring events and studying their effects on behaviour without the manipulation of the IV

Natural experiment AO1 points

• have naturally occuring IV (not manipulated by researcher)

• there is a DV that is measured by the researcher to test impact of IV

• take place in real life natural environment of the participants

• researchers are unable to control any extraneous variables that could affect data

Natural experiment AO3 points

• Naturally occurring IV’s enable researchers to test variables that would otherwise be unethical to create artificially

• can use standardised + objective measures

• high ecological validity in findings as context and conditions are not artificial

• extraneous variables can affect findings reducing validity

Interview description

A data collection method where the researcher asks participants questions(structured or unstructured).

Interview AO1 points

• structured Interviews - researcher asks pre set questions in fixed order

• semi structured interviews - researcher uses pre set questions but has flexibility to explore responses further.

• unstructured interviews - researcher asks open-ended questions + follows participant’s responses(more natural flow of conversation.)

• gather qualitative data which can provide rich detailed information about the person’s thoughts feelings and experiences

• used to explore, opinions, and attitudes. Particularly useful when studying sensitive topics/ exploring complex behaviours

interviews AO3 points

• qualitative data → deep insight into participants unique views + experiences - validity

• clarification is possible → more accurate results

• Time consuming to conduct + analyze

• Interviewer can influence/lead participants response → lowers validity

• Demand characteristics - participants may alter their response in order to seem as good person/what researcher wants to hear

Questionnaire description

Participants answer a set of questions, written or electronically, to collect data (qualitative/quantitative).

Questionnaire AO1 points

• can gather quantitative + qualitative data through closed and open ended questions

• can be retested to check for consistency and reliability of the items

• items may reflect the ideas of the researcher and could contain bias or leading questions.

• can be easy to distribute to a large sample of the population in comparison to other methods.

Questionnaire AO3 points

• closed questions don’t allow pp to explain their choice → lacks depth and context.

• replication of questionnaire → data can be compared to identify trends in behaviour

• respondents might understand the questions differently → reduces validity.

• Large scale samples → more accurate as it reduces affect of anomalies

correlation description

examines relationship between 2 variables to see if they are linked without manipulating IV

correlation AO1 points

• does not involve manipulating variables only looking at naturally occuring patterns

• strength + direction of relationship is represented by a number between 1 and -1. ( closer to +1 = stronger relationship)

• Can be a negative, positive or no correlation

• commonly used when experiments are not feasible/ethical

correlation AO3 points

• can highlight potential relationship between variables even when IV is not manipulated.

• researchers don’t manipulate variables → less invasive + more ethical (especially with sensitive topics)

• correlation does not = causation. Something could have happened due to third variable

• even though 2 variables correlate it is unclear whether one variable causes the other

case study description

an in depth study of an individual or small group often using multiple data collection methods over an extended period

case study AO1 points

• not representative of a larger population → focus on one’s unique experience

• gathers in depth + detailed qualitative data about a person

• can follow ethical requirement to make sure risk to pp is limited

• can combine different research methods to check findings and make comparisons

case study AO3 points

• rare cases are unique to the one person → limit generalisability of findings

• In depth → can produce data that provides a valid representation of the case

• can be questionable whether ethical guidelines can be fully achieved (cannot give informed consent)

• reliability of case study can be improved when pp repeats experimental tasks.

observation description

researcher watches and records participants’ behaviour in a natural/controlled environment

observation AO1 points

• in structured observations the observer controls setting + apparatus

• overt observations - when pp are aware of the observation

• overt observations allow researchers to meet ethical issues

• covert observation - pp are unaware of the observation

• naturalistic observations take place in a naturalistic setting where context is not manipulated

observation AO3 points

• strict controls → easy replicated → can test reliability

• covert observation → reduces issues of social desirability

• overt observations → pp aware of aims → demand characteristics (findings do not represent natural behaviour)

• artificiality → reduces ecological validity (results may not represnt how people behave in naturalistic settings)