IB Theory of Knowledge | 200 TOK Essay Words

Use these 200 IB Theory of Knowledge essay words to evaluate how claims are justified, compare methods across areas of knowledge and explain the implications of an argument. Each entry gives a meaning and a natural usage example.

The IB Diploma Programme assesses Theory of Knowledge through an exhibition and a separate externally assessed essay of up to 1,600 words. Choose one of the six prescribed essay titles for your own examination session and follow its instructions.

The 200-word list

1–20 Knowledge, methods and justification · 21–40 Taking a position · 41–60 Using evidence and reasoning · 61–80 Connecting ideas · 81–100 Explaining cause and effect · 101–120 Testing an issue and its boundaries · 121–140 Evaluating limits and assumptions · 141–160 Synthesising sources · 161–180 Building commentary and argument · 181–200 Testing evidence and reasoning

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

1–20 Knowledge, methods and justification

epistemic — relating to knowledge or justification. an epistemic limit of the method.
knower — a person or group considered as producing or using knowledge. the position of the knower shapes access to evidence.
justification — reasons or evidence that support accepting a claim. the justification depends on the method.
warrant — a reason or principle linking evidence to a claim. test the warrant for an inference.
certainty — confidence that a claim is true or settled. distinguish confidence from certainty.
fallibility — the capacity to be mistaken. acknowledge the fallibility of observers.
objectivity — efforts to reduce dependence on individual preferences or perspectives. procedures can improve objectivity.
subjectivity — the influence of an individual’s perspective or experience. subjectivity affects a viewer’s interpretation.
intersubjective — shared or checked across different people. intersubjective agreement among observers.
replication — repeating a study or procedure to test a result. replication tests whether the result holds.
reproducibility — the ability to obtain consistent results under a specified method. check the reproducibility of an analysis.
axiom — a starting proposition accepted within a formal system. a proof depends on the chosen axioms.
proof — a deductive demonstration that a conclusion follows from accepted premises. a mathematical proof establishes a result within a system.
paradigm — a shared model or framework guiding work in a field. a paradigm shapes what counts as a useful question.
operationalise — define an idea in terms of procedures or observations that can be measured. operationalise confidence in a survey.
underdetermination — a situation in which available evidence permits more than one explanation. underdetermination limits a firm conclusion.
interpretive — concerned with explaining meaning. an interpretive approach to an archive.
correspondence — agreement between a claim and what it describes. test correspondence with observations.
coherence — the fit of claims or ideas with one another. coherence within an explanation.
reflexivity — critical attention to how one’s own role affects a process. reflexivity in an interview study.

21–40 Taking a position

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

41–60 Using evidence and reasoning

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

61–80 Connecting ideas

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

81–100 Explaining cause and effect

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

101–120 Testing an issue and its boundaries

absolutist — treating a rule or claim as admitting no exception. an absolutist reading of the recommendation.
generalisability — the extent to which a finding applies beyond its original setting. test the generalisability of a pilot result.
necessary — required for a result or condition. a necessary condition for participation.
sufficiency — the quality of being enough to establish or achieve something. question the sufficiency of one example.
counterfactual — a reasoned account of what might happen under different conditions. consider a counterfactual without the policy.
falsifiable — capable in principle of being shown false by evidence. a falsifiable claim about participation.
confound — make the effect of one factor hard to separate from another. age may confound the comparison.
causal — concerned with a relationship in which one thing produces an effect. a causal explanation of the decline.
conditional — true or applicable only when a requirement is met. conditional support for a public subsidy.
contingent — dependent on a particular circumstance. the benefit is contingent on consistent access.
generalise — draw a conclusion that covers cases beyond those observed. generalise cautiously from a local trial.
speculative — based on possibilities that have yet to be established. a speculative prediction about behaviour.
prescriptive — setting out what people should do. a prescriptive claim about public spending.
descriptive — stating what is observed or claimed to happen. a descriptive statement about current practice.
presume — take something to be true as a starting point. presume that users have reliable internet.
necessitate — make an action or condition necessary. a larger intake may necessitate extra staff.
invalidate — make a claim or inference no longer valid. one error can invalidate the comparison.
indeterminate — not settled or precisely known. the long-term effect remains indeterminate.
unwarranted — unsupported by sufficient reason or evidence. an unwarranted inference about demand.
tenability — the ability of a view to withstand reasonable criticism. test the tenability of a broad claim.

121–140 Evaluating limits and assumptions

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

141–160 Synthesising sources

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

161–180 Building commentary and argument

commentary — reasoning that explains how evidence supports a claim. develop the commentary after a quotation.
governance — how institutions make and carry out decisions. local governance shapes enforcement.
grounds — the basis or reasons for holding a position. give grounds for a limited trial.
scope — the range of cases a statement or argument covers. limit the scope of the argument.
inference — a conclusion reached from available evidence. draw an inference from the pattern.
deduction — reasoning in which a conclusion follows necessarily from its premises. reach the conclusion by deduction.
generalization — a broad statement drawn from specific cases. a generalization from a narrow sample.
analogue — a comparable case with a similar structure or function. an analogue from a neighboring district.
precedent — an earlier case used as a guide for a later one. cite a legal precedent.
exception — a case to which a rule or pattern does not apply. allow for an exception.
criterion — a single standard for judging something. use reliability as one criterion.
condition — a circumstance required for a claim or proposal to hold. state a condition for success.
implication — what follows from a statement even when left unstated. consider the implication for families.
counterexample — a case that shows a general claim does not always hold. offer a counterexample to an absolute claim.
oversimplification — an explanation that drops important complexity. avoid oversimplification.
falsehood — a statement that is untrue. identify a falsehood in a source.
equivocation — a shift between meanings of a term within a line of reasoning. detect equivocation over the meaning of freedom.
jurisdiction — the area or matters over which an authority has legal power. within the regulator’s jurisdiction.
tentative — held provisionally pending stronger evidence. a tentative explanation.
defensible — capable of being supported with sound reasons. a defensible thesis.

181–200 Testing evidence and reasoning

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

What the TOK essay asks you to investigate

Use the exact prescribed title for your session. Underline the relationship it asks you to evaluate, then identify any areas of knowledge it requires. The guide discusses history, the human sciences, the natural sciences, the arts and mathematics. A strong response develops an argument about the production, use or justification of knowledge through relevant examples.

The TOK exhibition is a separate assessment. In the essay, keep the title in view, support your arguments with specific examples, consider different points of view and explain the implications. Terms such as epistemic and warrant are useful when they identify an actual feature of a claim or method.

IB Theory of Knowledge course overview · IB TOK guide · IB guidance and examples for prescribed essay titles

Word list · Worked response

A worked comparison of two areas of knowledge

Original practice question for this guide, separate from the IB’s prescribed titles. When does agreement among experts give us good reason to accept a claim? Consider history and mathematics.

In history, agreement may carry weight when researchers working with different evidence reach compatible accounts of an event. Two historians repeating the same official record still depend on that record for the claim. Agreement across administrative files, private correspondence and other relevant evidence can provide a stronger basis, though missing records may still limit the conclusion. What matters is how the evidence behind the agreement was produced and checked.

In mathematics, agreement among experts may give a learner confidence that a proof has been scrutinised. The justification of the result depends on the reasoning within the proof and on the assumptions under which it is established. The comparison shows two functions of agreement. It can offer practical assurance to a knower who cannot check everything independently, while the grounds of the underlying claim differ across areas of knowledge.

Word list · Exam requirements · Worked analysis

Keep an example tied to a knowledge claim

When using a historical example, separate the source’s content from the explanation you infer. A treaty text can establish what was formally agreed. Evidence about negotiations or implementation may be needed to judge why particular conditions were accepted or whether the agreement worked. The type of claim determines what counts as appropriate evidence.

When using mathematics, avoid treating a pattern in a handful of cases as proof of a general statement. Try finding one pattern you can test on a few examples, then write what a proof would have to establish. You can compare that requirement with a historical question where no deductive proof is available but evidence can still strongly support an interpretation.

A useful cross-area comparison has a common question and a difference in method. State what both areas are trying to establish. Then explain why a kind of evidence that is strong in one setting may have a different role in the other. Return to the title after each comparison.

Word list · Worked response · Fencing Method

How to fence a TOK word

1. Base. The claim needs justification. 2. Detail. The historical claim needs justification beyond one official record. 3. Tone. A single record may support a narrow claim about the stated decision. 4. Logic. Because the record describes the decision but does not reveal every motive, a claim about why it was made needs other evidence. 5. Transfer. A few numerical examples can suggest a conjecture while leaving its general justification open.

Distinguish a reason you personally trust from a reason that can be checked by others. A method may improve objectivity by letting people examine the same evidence or procedure. Describe exactly what becomes checkable. Avoid assuming that a shared method removes every limitation.

The eduKate Fencing Method for Vocabulary

Word list · Worked analysis · Practice and FAQs

Plan and revise around the prescribed title

Write the title at the top of your plan. Draft a tentative answer in one sentence. For each area, note a specific example, what kind of claim it supports, a competing view and what would change your judgement. Choose examples that help test the title. An interesting story may still be irrelevant to the kind of knowledge the essay examines.

Can I submit one of the practice prompts here? Use an official prescribed title for your own session. Is 1,600 a maximum? Yes. Do I always choose the same two areas? Follow the actual wording. Can a term replace a worked example? The term helps describe the reasoning, and the example allows a reader to assess it.

After drafting, identify the paragraph that would still make sense if the title were changed to another question. Revise its central claim so it addresses the actual issue. Then check how each example is sourced and what it establishes. Give competing interpretations a fair account before deciding how much weight each deserves.

Word list · Fencing Method · Revision

Check the implication of your argument

An implication tells the reader what follows from your reasoning. If you argue that agreement is more informative when sources are independent, an implication is that a repeated claim should be traced to its underlying evidence before counting it as corroboration. This step goes beyond saying the argument is important.

Write one implication for each area you compare. Then see whether they can be connected. Historical reasoning and mathematics may both benefit from scrutiny by others, while the object of scrutiny differs. In one case, readers may check the source and inference. In the other, they may check whether a step follows from the assumptions.

Word list · Practice and FAQs

Practice workshop

Unpack a term in relation to the title

Choose a key word such as reliable, valuable or certain. Write what it means for the particular claim you are evaluating. Then test whether it has the same practical meaning in the other area of knowledge. If the meanings differ, make that difference part of the argument.

Distinguish agreement from independent support

Imagine three accounts all based on one official statement. Ask how many independent sources support the claim. Now add a record produced for a different purpose. Explain what new information it contributes. The number of people repeating a statement is a different question from the variety or independence of the evidence.

Separate a claim from the method used to check it

A historical claim about a date can sometimes be checked directly against a record. A claim about motive may need several kinds of evidence. Write a sentence specifying the claim and a sentence explaining the check. Compare that process with examining whether a proof’s conclusion follows from its assumptions.

Make a counter-position change the essay

Choose a competing answer that a reasonable reader could hold. If you argue that agreement is a good guide, consider a community whose members share the same evidence and methods. Explain where agreement remains useful and where shared limitations reduce its force. Then revise the main claim to reflect the distinction.

State what an example can establish

Write two sentences about a concrete example you can source. The first should describe what happened or what the procedure shows. The second should explain its relevance to the title. If you remove the example and your reasoning is exactly the same, identify what the example should test or replace it with a stronger one.

Compare areas on a common question

Ask the same question of both areas, such as what another person can check. In history they may check the record and inference. In mathematics they may check the deduction. Describe the difference without implying that one method must be appropriate everywhere. Then decide what follows for the precise wording of the title.

Give the conclusion an implication

If the essay finds that methods matter more than the number of people who agree, explain what a learner or researcher should check next. A conclusion may also specify where the comparison breaks down. Use only implications supported by your earlier analysis. Check the word limit and the prescribed title before the final read.

Check an example against the word limit

Use enough detail to make the reasoning checkable. A reader may need to know who produced a record, what the record shows and why it is relevant. The same reader may need very little of the surrounding story. When editing, cut plot or background before cutting the explanation that connects the example to the title.

Next reading

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GRE Analyze an Issue · Cambridge A Level Thinking Skills 9694 · Back to the 200-word list

Top 200 Vocabulary Word List for IB Theory of Knowledge (TOK) | Essay Writing