IB Psychology HL

Variable

Any characteristic that is objectively registered and quantified

Construct

Any theoretically defined variable

Operationalization

Expressing a construct in terms of observable, measurable behavior

Independent Variable

The variable manipulated by the experimenter

Dependent Variable

The variable that changes when other variables are manipulated

Confounding Variables

Potential variables that can interfere with the experiment

Target Population

The group of people to which the findings of the study are expected to be generalized

Sample

The group of people that take part in the experiment

Representative Sample

If a sample reflects all of the essential characteristics of the target population

Random Sampling

When every member of the target population has an equal chance of becoming part of the sample (if the sample is a large size, researchers can be certain that even unexpected characteristics are fairly represented but it’s practically impossible)

Stratified Sampling

When participants are recruited randomly based on essential characteristics of the population that the sample is supposed to reflect (it allows researchers to control representativeness of some key characteristics but it requires more knowledge)

Convenience Sampling

When participants are recruited based on who is easily available (it’s cheap and easily accessible but generalization is limited)

Self-Selected Sampling

When participants are recruited on a volunteer basis through public ads (it’s quick and easy with large coverage but representativeness and generalization are limited)

Independent Measures Design

When the independent variable is manipulated by randomly allocating participants into different groups and each participant only faces one condition

Matched Pair Design

When the independent variable is manipulated by using matching to form groups based on specific characteristics and each participant only faces one condition

Repeated Measures Design

When the same group of participants is exposed to two or more conditions and the conditions are compared

Order Effect

When the results of subsequent trials in a repeated measures experiment are affected by the fact of participation in the previous trials and leads to either practice or fatigue

Counterbalancing

When the researcher randomly forms two groups of participants and the order of trials in the group is reversed in order to prevent the order effect.

Construct Validity

The quality of operationalizations

External Validity

A characteristic of generalizability to other people and other situations

Population Validity

The extent to which findings can be generalized from the sample to the target population

Ecological Validity

The extent to which findings can be generalized from the experiment to other settings or situations

Internal Validity

The methodological quality of the experiment

Selection Bias

When groups are not equivalent at the start of the experiment

History Bias

When outside events that happen to participants in the course of the experiment

Maturation Bias

When the participants go through natural developmental processes in the course of the experiment

Testing Effect

When the first measurement of the dependent variable may affect the second

Instrumentation Bias

When the instrument measuring the dependent variable changes slightly between measurements

Regression to the Mean

When there are extreme scores, they tend to become more average in subsequent trials

Experimental Mortality

When people drop out of the experiment

Demand Characteristics

When the participants know the purpose of the experiment and change their behavior

Experimenter Bias

When the researcher unintentionally exerts an influence on the results of the study

Laboratory Experiment

When the researcher manipulates the independent variable and is able to control all other variables (is easy to replicate and establishes a cause and effect relationship but has limited external validity and has a higher potential for demand characteristics)

Field Experiment

When an experiment takes place in a natural environment but the researcher still manipulates the variables (has more ecological validity and a lower chance of demand characteristics but has more confounding variables, ethical issues, and can be difficult to replicate)

Natural Experiment

When the researcher has no control over variables (has high ecological validity and little to no bias but is impossible to replicate and determine cause and effect and has ethical issues)

Quasi-Experiment

When there is no manipulated independent variable and only naturally occurring traits are compared

Correlational Study

When no variable is manipulated by the researcher so no cause and effect relationships can be determined, but correlation is mathematically quantified

Negative Correlation

When there is an inverse relationship between variables

Positive Correlation

When there is a direct relationship between variables

Curvilinear Relationship Bias

When the correlation between two variables is calculated and assumed to be linear, but is actually a curve

Third Variable Problem

There is always a possibility that a third variable exists that correlates with the existing variables and explains the correlation between them

Spurious Correlations

When correlations are obtained by chance

Qualitative Research

Research that is more focused on richer, non-numerical data

Triangulation

When a combination of different approaches are used to collect and interpret data (using methods, data, researchers, or theories)

Establishing a Rapport

When researchers ensure that participants are being honest and that they know their rights

Iterative Questioning

When the researcher spots ambiguous answers and returns to the topic later while at the same time rephrasing the question to combat lying and otherwise manipulating results

Reflexivity

When researchers reflect on the possibility that their own biases might have interfered with the observations or interpretations

Epistemological Reflexivity

Reflexivity linked to knowledge of the strengths and limitations of the method used to collect data

Personal Reflexivity

Reflexivity linked to the personal beliefs and expectations of the researcher

Credibility Checks

Checking the accuracy of data by asking participants themselves to read transcripts of interviews of field notes of observations and confirm that the transcripts or notes are an accurate representation of what they said or did

Thick Descriptions

Explaining not just the observed behavior itself, but also the context in which it occurred so that the description becomes meaningful to an outsider who never experienced the phenomenon firsthand

Acquiescence Bias

The tendency to give positive answers whatever the question

Social Desirability Bias

The participants’ tendency to respond or become in a way that they think will make them liked or accepted

Dominant Respondent Bias

Occurs in a group interview setting when one of the participants influences the behavior and responses of the others

Sensitivity Bias

A tendency of participants to answer regular questions honestly, but distort their responses to questions on sensitive subjects

Confirmation Bias

When the researcher has a prior belief and the researcher uses the research in an unintentional attempt to confirm that belief

Leading Questions Bias

When respondents in an interview are inclined to answer in a certain way because the wording of the question encourages them to do so

Question Order Bias

When responses of one question influence the participants’ responses to the following questions

Biased Reporting

When some findings of a study are not equally represented in the research report

Sample-to-Population Generalization

Generalizes the results of a sample to the target population

Theoretical Generalization

Generalizes the results as a support for a broader theory

Case to Case Generalization

Generalizes results to a different group of people or a different setting or context

Quota Sampling

When it is decided before the start of the research how many people to include in the sample and which characteristics they should have

Purposive Sampling

When the target characteristics of participants are defined in advance but the composition of the sampling is not

Snowball Sampling

When a small number of participants are invited then are asked to invite people they know who also have the characteristics of interest to the researcher

Overt Observation

When participants are aware of the fact that they are being observed (ethical through informed consent but participants’ expectations may influence their behavior)

Covert Observation

When participants are observed without the researcher informing the members of the group about the reasons for their presence (participants do not suspect that they are being observed so they behave naturally but they often do not consent to being observed)

Participant Observation

When the observer becomes part of the observed group (allows the researcher to experience the phenomenon firsthand but there is a risk that objectivity can be lost)

Non-Participant Observation

When the observer does not become part of the observed group (more impartial but some details about the observed group can only be understood from the perspective of a group member)

Structured Interview

Interviews that include a fixed list of questions that need to be asked in a fixed order (allows all interviews to be consistent with several participants but some participants may have unique conditions that cannot be accommodated)

Semi-Structured Interview

Interviews that do not specify on order or a particular list of questions (fits the natural flow of conversation and each participant’s unique experiences better but there is less comparability across researchers and participants)

Unstructured Interviews

Interviews that are participant-driven where every question is determined by the interviewee’s previous answer (very effective for investigating unique cases and limits the wording effect but is more time-consuming)

Focus Group

A special type of semi-structured interview that is conducted simultaneously with a small group of people to study group dynamics (encourages more natural behaviors, adds several perspectives to questions, and makes it easier to answer sensitive questions but can be impacted by dominant respondents and a lack of anonymity)

Case Study

An in-depth investigation of an individual or a group over time (can contradict old theories and usually uses triangulation but there is limited confidentiality and generalization is problematic)

Informed Consent

Participants must be informed about the nature of the study and agree to participate

Protection from Harm

No harm should be done to participants but if there is any threat, participants should be informed beforehand

Anonymity and Confidentiality

Confidentiality muster must be guaranteed and outlined in the consent form and if there are any limits they should be clearly stated

Right to Withdrawal

Participants are allowed to drop out of the experiment at any point

Deception

Deception cannot be used unless there is no other way to get the data, the risk from harm is not great, and participants are debriefed as soon as possible

Debriefing

All participants must be told the nature of the experiment after the data is collected, be able to see the data, and have a right to withdraw their data if they wish