Top 200 Vocabulary Word List for IB Diploma Programme Psychology (SL and HL) | Essay Writing

Use these 200 IB Psychology words to write a concept-based extended response, evaluate research and explain how evidence applies to a context. Each entry gives a meaning and a short usage example.

From first assessment in 2027, IB Psychology Paper 1 lasts 1 hour 30 minutes at SL and HL. Section C asks you to answer one of two concept-based extended-response questions. It is worth 15 marks within the 35-mark paper.

The 200-word list

1–20 Concepts and contexts in IB Psychology · 21–40 Design, measurement and ethics · 41–60 Memory, learning and explanation · 61–80 Taking a position · 81–100 Using evidence and reasoning · 101–120 Connecting ideas · 121–140 Explaining cause and effect · 141–160 Synthesising sources · 161–180 Testing evidence and reasoning · 181–200 Evaluating limits and assumptions

Exam requirements · Worked response · Worked analysis · Fencing Method · Practice and FAQs · Practice workshop

1–20 Concepts and contexts in IB Psychology

1. perspective — a standpoint or framework used to interpret behaviour. compare cognitive and sociocultural perspectives.
2. responsibility — an obligation to consider the consequences of inquiry or action. researcher responsibility includes protecting participants.
3. measurement — the process of assigning observations or scores using a rule. evaluate the measurement of recall.
4. change — a difference over time or between states. distinguish measured change from a practice effect.
5. causation — a relationship in which one factor produces an effect. a controlled experiment can support a claim about causation.
6. bias — a systematic influence on observations or conclusions. question whether observer bias affected the record.
7. cognitive — relating to mental processes such as memory or reasoning. a cognitive account of memory.
8. biological — relating to bodily systems or processes. a biological explanation of behaviour.
9. sociocultural — relating to social relationships and cultural contexts. a sociocultural explanation of learning.
10. context — the situation in which a concept or behaviour is examined. apply the concept in the learning and cognition context.
11. triangulation — using several methods, sources or perspectives to examine a question. triangulation can test whether findings converge.
12. reflexivity — attention to how a researcher’s position affects inquiry. reflexivity is important when interpreting interviews.
13. reactivity — behavioural change caused by awareness of being studied. reactivity can affect a classroom observation.
14. transferability — the potential relevance of a finding to another context. assess the transferability of the finding.
15. positionality — the way a person’s role or background shapes their standpoint. researcher positionality can influence interpretation.
16. developmental — relating to changes across the lifespan. consider developmental differences in task performance.
17. dyadic — involving two people or units in a relationship. a dyadic interaction between partners.
18. reciprocity — mutual influence or exchange. reciprocity can shape relationships.
19. enculturation — learning the practices and meanings of a culture. enculturation can shape expectations.
20. cross-cultural — involving comparison or work across cultures. a cross-cultural design requires comparable measures.

21–40 Design, measurement and ethics

21. operationalisation — specifying how an idea will be measured or manipulated. operationalisation turns recall into a score.
22. construct — an abstract concept that cannot be observed directly. memory accuracy is a construct.
23. validity — how well a measure or inference supports its intended interpretation. evaluate whether the task measures the construct.
24. reliability — consistency of measurement or results under specified conditions. check inter-rater reliability.
25. replication — repeating a study or procedure to test a finding. a replication uses the same core manipulation.
26. sampling — selecting cases or participants from a population. sampling affects who is represented.
27. random allocation — assigning participants to conditions by chance. random allocation can reduce systematic group differences.
28. control condition — a comparison condition without the critical manipulation or with an alternative treatment. compare the experimental and control conditions.
29. confound — a variable that changes with the factor of interest and offers another explanation. prior exposure could confound the result.
30. standardisation — keeping procedures consistent across participants or settings. standardisation helps isolate the wording change.
31. demand characteristics — cues that suggest what a study expects from participants. demand characteristics may influence answers.
32. social desirability — a tendency to give answers viewed favourably by others. social desirability can affect self-reports.
33. observer effect — a change associated with being observed. the observer effect may alter classroom behaviour.
34. generalisation — extension of a finding beyond the cases or conditions studied. limit generalisation from a narrow sample.
35. consent — agreement to participate based on appropriate information and choice. obtain informed consent.
36. debriefing — explaining the study after participation and addressing questions or concerns. debriefing can explain why details were withheld.
37. anonymity — a condition in which identities are not known or linked to responses. anonymous responses can reduce some disclosure concerns.
38. confidentiality — protection against unauthorised disclosure of information. maintain confidentiality in the interview records.
39. self-report — information participants provide about themselves. a self-report may differ from observed behaviour.
40. attrition — loss of participants over the course of a study. attrition can change the composition of the final sample.

41–60 Memory, learning and explanation

41. encoding — conversion of information into a form that can be stored. encoding may depend on attention.
42. retrieval — accessing stored information. a cue can aid retrieval.
43. reconstruction — rebuilding a memory using stored information and other inputs. reconstruction may incorporate later wording.
44. interference — disruption of recall or learning by competing information. similar material can produce interference.
45. misinformation — inaccurate information that can influence a later report. post-event misinformation may change a response.
46. leading — phrased in a way that suggests a particular answer. a leading question can affect an estimate.
47. schema — an organised framework of prior knowledge. a schema can shape interpretation.
48. cue — a signal that helps evoke a response or memory. a contextual cue can prompt recall.
49. conformity — changing behaviour or judgement in response to group pressure. public conformity may reflect social pressure.
50. compliance — outward agreement or action without necessarily changing private belief. compliance can end when pressure is removed.
51. internalisation — acceptance of a view as part of one’s own belief. internalisation can persist privately.
52. obedience — following a direct instruction from an authority. obedience depends partly on perceived authority.
53. attachment — an enduring emotional bond. evaluate how attachment is assessed.
54. reinforcement — a consequence that increases the likelihood of a behaviour. reinforcement can maintain a learned response.
55. conditioning — learning through associations or consequences. compare different forms of conditioning.
56. mediational — concerned with processes that intervene between stimulus and response. a mediational process such as attention.
57. reductionism — explaining a complex phenomenon through simpler components or a single level. evaluate whether the account is reductionist.
58. determinism — the view that behaviour is governed by causes or conditions. compare different forms of determinism.
59. idiographic — focused on individuals and their particular experiences. an idiographic approach can reveal personal meaning.
60. nomothetic — aimed at general patterns or laws. a nomothetic approach seeks common patterns.

61–80 Taking a position

61. claim — a statement you want the reader to accept. make a claim.
62. stance — your position on a question. take a clear stance.
63. thesis — the central position or interpretation your response develops. support the thesis.
64. premise — an idea the argument starts from. question the premise.
65. assumption — something treated as true without being established. test the assumption.
66. assert — state a position firmly. assert that access matters.
67. argue — give reasons in support of a position. argue for a trial.
68. maintain — continue to hold or defend a view. maintain that the policy is fair.
69. contend — put forward a position that can be challenged. contend that the proposal is workable.
70. justify — give sufficient reasons for a decision or judgement. justify the expense.
71. advocate — publicly support an action or change. advocate for reform.
72. defend — answer criticism of a view or choice. defend a decision.
73. qualify — limit a statement so it applies only where warranted. qualify the conclusion.
74. concede — acknowledge a valid point made by the other side. concede that costs may rise.
75. rebut — answer an opposing claim with reasoning or evidence. rebut the objection.
76. counterargument — a reasoned objection to a position. address a counterargument.
77. reservation — a concern that makes agreement incomplete. express a reservation.
78. distinguish — show what makes two things different. distinguish cost from value.
79. criteria — standards used to judge something. agree on the criteria.
80. verdict — a final judgement reached after consideration. reach a verdict.

81–100 Using evidence and reasoning

81. evidence — information that helps establish a claim. draw on evidence.
82. example — a specific case that makes a general point clearer. give a concrete example.
83. illustrate — make an idea clearer through a case or detail. illustrate the difficulty.
84. demonstrate — show how or why something is true. demonstrate a connection.
85. substantiate — support a claim with convincing information. substantiate the allegation.
86. corroborate — provide independent support for an existing account. corroborate the witness’s account.
87. infer — draw a conclusion from available clues. infer a motive from the wording.
88. imply — suggest a meaning without saying it directly. imply that change is possible.
89. interpret — explain what something means in context. interpret a figure in context.
90. analyse — examine how parts work together. analyse the writer’s choices.
91. evaluate — judge the strength, quality or value of something. evaluate the proposal.
92. plausible — reasonable enough to believe given what is known. a plausible explanation.
93. credible — worthy of belief or trust. a credible source.
94. relevant — directly connected to the issue being considered. relevant to the question.
95. sufficient — enough for the purpose or conclusion at hand. sufficient for a limited trial.
96. representative — typical enough to reflect a larger group. a representative sample.
97. anecdote — a brief account of a particular incident. open with an anecdote.
98. limitation — something that restricts what a method or claim can establish. acknowledge a limitation.
99. contradict — state or show something incompatible with another claim. contradict the earlier finding.
100. synthesise — combine ideas from separate sources into a new account. synthesise competing accounts.

101–120 Connecting ideas

101. whereas — introduces a clause that contrasts with another. whereas the first option costs less.
102. although — introduces a fact that qualifies the main statement. although demand may rise.
103. however — signals a contrast or change in direction. however, costs remain uncertain.
104. nevertheless — signals that a point still holds despite a difficulty. nevertheless, the trial could go ahead.
105. conversely — introduces a contrasting relationship in the reverse direction. conversely, lower demand can free capacity.
106. similarly — points out a meaningful likeness. similarly, smaller groups need space.
107. likewise — shows that a similar point applies elsewhere. likewise, evening users need lighting.
108. consequently — introduces a result of what came before. consequently, the queue grew.
109. therefore — introduces a conclusion or result that follows. therefore, a trial is justified.
110. furthermore — adds a supporting point. furthermore, the existing room is free.
111. specifically — narrows the discussion to a precise detail. specifically, the plan would add two sessions.
112. instead — signals a replacement or different choice. instead, use the current building.
113. alternatively — introduces another option. alternatively, change the timetable.
114. otherwise — indicates what happens under different conditions. book early, otherwise places may fill.
115. provided — introduces a condition when used with a following clause. provided that staffing is adequate.
116. despite — introduces something that fails to prevent the main outcome. despite the delay.
117. unlike — marks a difference between two things. unlike the previous scheme.
118. respectively — matches items with values in the same stated order. costs were $5 and $8, respectively.
119. overall — signals a judgement about the whole picture. overall, the benefits are modest.
120. ultimately — identifies what matters after other factors are considered. ultimately, the decision depends on demand.

121–140 Explaining cause and effect

121. cause — produce or bring about an outcome. cause avoidable delays.
122. contribute — play a part in bringing about an outcome. contribute to overcrowding.
123. trigger — set a process or reaction in motion. trigger a review.
124. accelerate — make a process happen faster. accelerate the transition.
125. intensify — make something stronger or more severe. intensify competition.
126. exacerbate — make an existing problem worse. exacerbate existing inequalities.
127. mitigate — reduce the severity or harmful effect of something. mitigate the harm.
128. prevent — stop something from happening. prevent further damage.
129. deter — discourage someone from taking an action. deter people from taking risks.
130. enable — make an action possible. enable students to attend.
131. facilitate — make an action or process easier. facilitate access to training.
132. reinforce — strengthen an effect, belief or behaviour. reinforce an existing pattern.
133. undermine — weaken something, often gradually. undermine public trust.
134. sustain — keep something going over time. sustain the improvement.
135. displace — push something or someone out of an existing place or role. displace smaller operators.
136. redistribute — change how something is shared. redistribute public funds.
137. consequence — an outcome that follows an action or event. an unintended consequence.
138. mechanism — the process through which an effect occurs. identify the mechanism.
139. correlation — a pattern in which two things vary together. observe a correlation.
140. constraint — a condition that limits what can be done. work within a budget constraint.

141–160 Synthesising sources

141. attribute — identify where an idea or quotation comes from. attribute the statistic to Source A.
142. cite — identify the source of material used in an argument. cite the survey in Source B.
143. paraphrase — restate a source’s meaning in your own words and structure. paraphrase the author’s reasoning.
144. excerpt — a passage taken from a longer work. an excerpt from a public address.
145. provenance — the origin and history of a piece of material. check the provenance of a photograph.
146. testimony — a person’s account offered as evidence. testimony from residents.
147. dataset — an organised collection of data. a dataset on bus ridership.
148. sample — a subset examined to learn about a larger group. a sample of city schools.
149. metric — a defined quantity used to measure performance or change. an attendance metric.
150. variable — a factor that may vary or be deliberately changed. control for a confounding variable.
151. baseline — a reference point used to judge later differences. measure change against the baseline.
152. methodology — the overall system of methods used to investigate a question. question the study’s methodology.
153. outlier — a result far from the others in a set. identify an outlier.
154. independent — arising separately from the source or factor under discussion. an independent source.
155. convergence — movement towards agreement or a shared conclusion. convergence between findings.
156. divergence — movement apart or difference between results or views. divergence between local and national data.
157. complement — add a missing part or strength to something else. complement the survey with testimony.
158. complicate — show that a simple explanation leaves important things out. complicate the initial conclusion.
159. reconcile — explain how apparently conflicting claims can fit together. reconcile the two findings.
160. triangulate — check a claim by comparing different independent sources or methods. triangulate claims across three sources.

161–180 Testing evidence and reasoning

161. intermediate — coming between earlier reasons and the main result. identify an intermediate conclusion.
162. unstated — implied without being expressed directly. an unstated assumption about access.
163. premiss — a proposition offered as a reason for a conclusion. test whether the premiss is true.
164. jointly — together rather than separately. the two reasons jointly support the claim.
165. deductive — involving an inference intended to follow necessarily. a deductive argument with a missing premiss.
166. inductive — involving reasoning that extends beyond the observed cases. an inductive inference from a survey.
167. abductive — concerned with inferring a likely explanation. an abductive inference from an unexpected result.
168. counterinstance — an example that goes against a general claim. one counterinstance challenges the rule.
169. equivocal — open to different meanings or interpretations. an equivocal use of the word free.
170. circular — using the conclusion itself as part of its supposed support. circular reasoning provides no independent reason.
171. fallacy — a flaw in reasoning. identify a fallacy in a forced choice.
172. confounder — a factor that can distort a proposed causal relationship. distance may be a confounder.
173. denominator — the reference total against which a count or rate is expressed. check the denominator in the reported rate.
174. response — a reply or a contribution to a survey. a low survey response rate.
175. self-selection — the process by which participants choose whether to take part. self-selection limits the survey.
176. comparability — the extent to which items can be fairly compared. question comparability across the two periods.
177. interested — having a stake that could affect an account. an interested source may still provide accurate data.
178. contemporaneous — made or existing at the same time as an event. contemporaneous records of attendance.
179. weight — the importance assigned to a piece of evidence. give more weight to direct measurements.
180. decisive — strong enough to settle a question under the available evidence. the documents do not provide decisive support.

181–200 Evaluating limits and assumptions

181. presuppose — treat something as already true before arguing. presuppose that demand is fixed.
182. conflate — treat distinct things as if they were the same. conflate availability with accessibility.
183. elide — leave out or pass over a distinction or detail. elide the difference between choice and constraint.
184. overgeneralise — draw a conclusion that covers more cases than the evidence allows. overgeneralise from one institution.
185. extrapolate — extend an observed pattern beyond the data available. extrapolate from a small pilot.
186. circumscribe — limit something to a defined range. circumscribe the policy’s application.
187. predicate — base a claim or decision on a condition. predicate success on continued funding.
188. reductive — simplifying a subject in a way that loses important detail. a reductive account of motivation.
189. tenable — capable of being maintained under criticism. a tenable explanation of the discrepancy.
190. fallacious — based on faulty reasoning. a fallacious comparison between unlike cases.
191. ambivalent — having mixed or opposing feelings about something. an ambivalent response to regulation.
192. normative — concerned with what ought to be done or valued. a normative claim about fairness.
193. empirical — based on observation or evidence from experience. empirical evidence on take-up.
194. asymmetry — a significant difference between two sides that are compared. an asymmetry in bargaining power.
195. contention — a claim presented as part of an argument. the contention that access is universal.
196. caveat — a warning or limitation attached to a statement. accept the proposal with a caveat.
197. paradox — an apparently contradictory situation or statement. the paradox of choice without access.
198. compatibility — ability to work or coexist together. compatibility with local practice.
199. salience — importance or prominence in a particular context. the salience of cost in the debate.
200. commensurate — matching another thing in size or degree. support commensurate with need.

What changes in the 2027 IB Psychology assessment

Paper 1 has short-answer content questions, short-answer applications to unseen situations and a Section C extended response. Section C offers two questions from different contexts. The four contexts are health and well-being, human development, human relationships, and learning and cognition. Choose one question and use the concept to drive the argument.

Paper 2 is a separate 1 hour 30 minute assessment at both levels. It covers class practicals and evaluation of an unseen study. HL also takes a 1 hour 45 minute Paper 3 on research data. Students assessed in 2026 or earlier should use their own course brief and practice materials.

IB Psychology course page and cohort briefs · IB Psychology guide, first assessment 2027 · Roediger and Karpicke on test-enhanced learning

Word list · Worked response

A worked concept-based paragraph on measurement

Original Section C-style exercise. Examine why measurement matters when evaluating a finding about learning and cognition. In Roediger and Karpicke’s 2006 experiments, students studied prose passages and either took recall tests or restudied. A later test measured retention at different delays. Restudying performed better at the briefest delay in the first experiment, while prior testing improved later retention.

The measurement interval changes the conclusion someone might draw. If learning is judged immediately, an approach can look effective because the material remains accessible shortly after study. If the criterion is retention after a delay, the relative result can change. The example shows why a claim about better learning should specify the outcome and time horizon. It does not establish that every retrieval task works the same way for every kind of learning.

A further evaluation can distinguish recall of studied prose from using an idea in a new problem. Both are legitimate outcomes, but they answer different questions. Explain which outcome supports the claim you are making.

Word list · Exam requirements · Worked analysis

Keep concept, context and content connected

Begin with a direct response to the concept in the question. Use psychological content to explain what happens in the relevant context. Then evaluate what the evidence supports. For example, measurement is the concept, learning and cognition is the context, and research comparing retrieval and restudy provides relevant content. The terms help organise the reasoning when the connection is visible.

A contrasting study or scenario should test the first point. A measure of confidence could capture how well learners think they have learned. A delayed recall test measures a different outcome. Use that contrast to show why the choice of measure can shape a conclusion.

Word list · Worked response · Fencing Method

How to fence an IB Psychology term

1. Base. The measure captures recall. 2. Detail. The delayed test measures recall of a prose passage. 3. Tone. The result supports a claim about delayed recall under the study conditions. 4. Logic. Because a different task would be needed to measure transfer, the finding should be applied to other kinds of learning with care. 5. Transfer. A recognition task and a free-recall task may support different claims about memory.

For a second fence, use responsibility with a specific decision. In a study using a classroom, explain what pupils need to know, how their information is protected and what would make participation voluntary in practice.

The eduKate Fencing Method for Vocabulary

Word list · Worked analysis · Practice and FAQs

Practice and frequently asked questions

Do I answer both Section C questions? Choose one. Does the 90 minutes cover only Section C? It covers all of Paper 1. What if I know a study well but cannot connect it to the concept? Choose evidence that helps explain the concept in the context named by the question.

Try evaluating bias in a short classroom observation scenario. Identify what the observer can see, what they might code differently and how an agreed recording rule could reduce variation. Then write a limitation that remains even after the procedure improves.

Word list · Fencing Method

Practice workshop

Name the concept before choosing a study

Write the exact concept asked about and one sentence explaining what it changes about the interpretation. Only then choose a study. If the concept is measurement, choose evidence where the measure matters. If it is responsibility, choose a decision about how a study was conducted, used or communicated.

Keep a learning outcome precise

Distinguish immediate performance, delayed retention and transfer to a new task. Each can be measured, but they are different outcomes. Write a claim about one of them and identify the time interval or task used to establish it. Check whether a second claim would need a different measure.

Use a finding and its boundary together

State what a study found under its conditions. Add one reason the effect could differ in another context. For example, material, timing or feedback may affect what a learner can retrieve. Explain why the new context differs before applying the original conclusion to it.

Distinguish a concept question from a study summary

Read your paragraph and circle the sentence that addresses the concept. If it appears only at the end, explain the connection earlier. Use only enough study detail for the reader to understand the argument. An accurate description becomes useful when it helps evaluate the concept in the named context.

Test causation through an alternative account

Imagine a comparison between pupils who choose different study strategies. A difference in later performance may reflect the strategy or a prior difference between the groups. Identify what a controlled design would help clarify and what its measures would still leave open. Then write the claim at the strength the design supports.

Evaluate an unseen research choice

Suppose a study uses a questionnaire about how often pupils practise recall. Participants may interpret the frequency categories differently. Explain how a clearer question might improve consistency and what a questionnaire still cannot directly observe. Connect the limitation to the specific conclusion about study behaviour.

Use two perspectives on the same evidence

A cognitive perspective might ask what makes information easier to retrieve. A sociocultural perspective might ask how a classroom’s routines shape who can practise and which performances are recognised. Identify what each perspective would explain in the same case. Then decide which is more relevant to the concept asked about.

Plan Section C under the whole-paper time limit

Practise the paper as a set of tasks. Leave time for Sections A and B as well as the extended response. In Section C, identify the context and concept before comparing the choices. Choose the question for which you can develop evidence and evaluation, rather than the one with the most familiar keyword.

Build a short counterpoint

If your argument favours a delayed measure, explain when an immediate measure could still be useful. For example, the goal may be to check understanding before moving to another task. The counterpoint can qualify your conclusion without undoing it. State which goal makes each measure appropriate.

Review whether the conclusion answers the command

If the question asks you to examine a concept, explain how it changes the way you interpret evidence. If it asks you to evaluate, make a judgement that weighs evidence or methods. Mark the sentence where you reach that judgement. If none does, write one that uses the limits you already discussed.

Use the topic in another context

Take the concept of measurement from learning into human development. Decide what behaviour you would observe, how you would score it and what age or setting could change the interpretation. Keep the method specific and explain why your conclusion should be limited to the outcome you measured.

Use a competing measure to sharpen a Section C judgement

Suppose a learner remembers the wording of a passage but struggles to apply its idea to an unfamiliar task. One measure would show retention. Another would show difficulty with transfer. This contrast does not make either measure invalid by itself. It shows why the claim about learning must match the outcome measured.

Build a short comparison using a different context. In human relationships, a questionnaire can record how people describe a disagreement, while observation can record selected behaviours. Explain which outcome fits the question and what each method might miss. Then return to the concept of measurement and state how it changes your interpretation of the evidence.

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