IB Psychology RM & Concept key terms 2025

Quasi

almost/kind of

True Experiment

A research that has the goal of finding a cause and effect relationship between an IV and DV, while controlling for potential influences including random allocation to conditions.

Quasi Experiment

Has an IV and DV and test a hypothesis but have less control than a true experiment, specifically the researcher doesn't manipulate the IV or randomly allocate participants to conditions.

Independent variable

A variable in experiments that changes and is manipulated.

Dependent variable

A variable in an experiment that is being measured to see the effect of an IV.

Extraneous variables

The variables of an experiment, that are not the independent variable, that may affect the outcome.

Control

Variables in an experiment, typically the extraneous variables, that must be restricted or held constant to prevent its influence on the outcome.

Correlation

A research method that measures the strength and direction of a relationship between two different covariables.

Covariables

The two sets of continuous data that are being tested in a correlation to look for a relationship.

Survey/questionnaire

Method using closed questions to easily collect self-reported data that can be compared across participants.

Closed questions

Questions with a limited set of responses such as yes or no.

Open questions

Questions that have open ended, or unrestricted, responses.

Likert/rating scale

A continuous rating scale that is used to measure the participants' opinions, attitudes or behaviours e.g. on a scale of 1-5.

Naturalistic Observation

An observation which is carried out in a natural context. The goal is to generate a hypothesis and understanding.

Controlled observation

An observation conducted in a controlled environment where researchers create a specific environment but without an Independent variable. The main goal is to understand behaviours.

Participant observation

An observation type where the researcher actively takes part in the same activities/experiences as the participants.

Non participant observation

An observation where the researcher remains separate from the participants without getting involved.

Covert observation

An observation during which the participant does not know that they are being observed.

Overt Observation

An observation during which the participant is aware that they are being observed.

Structured interview

An interview type with pre-set and fixed questions so all participants are asked the same question in the same order.

Semi-structured interview

An interview type with some set questions and topics but the interviewer has flexibility to ask spontaneous questions, ask follow up questions or change the order of questions.

Focus group interview

An interview type where a small group of people (9-12) take part in a semi-structured style interview.

Case study

An in-depth study of a single situation or event that actually occurred using multiple methods of data collection. Useful to generate new theories.

Method Triangulation

Using multiple data collection techniques to study the same topic in order to get a more accurate understanding from the combined results.

Opportunity (AKA convenience)

taking a sample from people who are available at the time the study is carried out .

Self-selected (AKA volunteer)

participants becoming part of a study because they volunteer when asked or in response to an advert.

Random sampling

where every member of the target population has a statistically equal chance of being chosen.

Stratified sampling

where researchers first identify 'strata' or groups of interest and recruit in a way that maintains the same proportion of people within each strata so that they are accurately represented within the final sample (like a nice even slice of cake)

Snowball sampling

where researchers identify a few participants, usually with unique characteristics, that they want to study and then get those existing participants to recruit further participants from among their acquaintances.

Sampling bias

when a sample leads to participants that are not reflective of the target population they are trying to study

Confirmation bias

the tendency for researchers to do/interpret findings in a way that leads to the answers they expected to see

Social desirability bias

the pressure to answer / act in ways seen as good by societal norms

Demand characteristics

when participants in an experiment are aware of the aims of the research and adapt their behaviour accordingly.

Reactivity

when participants act differently due to an awareness of being observed/studied.

Internal Validity

accuracy of measurements in a study (experiments & correlations only)

External validity / generalisability

accuracy of applying findings beyond a study

Credibility

how believable or trustworthy research is (qualitative term)

Bidirectional ambiguity

the uncertainty over whether one variable causes another or vice versa.

Informed consent

participants being fully aware of what a study involves and willingly agreeing to take part.

Confidentiality

researchers ensuring that data gathered within studies is kept secret (e.g. password protected) and only published in a way that wouldn't allow people to identify who the participants were

Debrief

a process at the end of research where researchers check in with participants to ensure they are physically/psychologically ok, fully aware of the study aims, answer any questions and checking they are still happy for their data to be included within the study.

Operationalisation

the process of turning a focus behaviour into a measurable thing.

Bias

a systematic error that distorts research

Measurement

quantifying psychological processes and behaviours

Causality

the degree to which we can demonstrate that one variable directly influenced another.

Perspective

a particular approach to explaining human behaviour

Change

transformations over time in people, behaviour or psychology

Responsibility

the duty to consider ethicality of research and actions in psychology