200 vocabulary words for age 15
- axiom
- theorem
- corollary
- lemma
- postulate
- quantifier
- existential
- universal
- tautology
- entailment
- biconditional
- converse
- inverse
- contrapositive
- syllogism
- abduction
- inductionism
- falsification
- replicability
- accuracy
- indeterminacy
- stochasticity
- randomness
- determinacy
- covariance
- counterfactuality
- confounding
- mediation
- moderation-effect
- interaction-effect
- homogeneity
- multicollinearity
- endogeneity
- exogeneity
- identifiability
- estimator
- parameterisation
- parameterization
- regularisation
- regularization
- penalisation
- penalization
- gradient
- descent
- ascent
- convexity
- concavity
- monotonicity
- differentiability
- integrability
- computability
- decidability
- tractability
- information
- encoding
- decoding
- authorisation
- auditability
- interpretability
- fairness
- fragility
- discrimination
- clustering
- embedding
- latent
- manifold
- topology
- geometry
- algebra
- calculus
- combinatorics
- statistics
- Bayesian
- frequentist
- posterior
- prior
- odds
- confidence
- credible
- p-value
- significance
- power
- effect-size
- sample-size
- sampling
- stratification
- blocking
- matching
- weighting
- instrumental
- propensity
- discontinuity
- intervention
- endpoint
- construct
- criterion-validity
- convergent-validity
- discriminant-validity
- predictive-validity
- content-validity
- face-validity
- interrater
- intrarater
- test-retest
- homomorphism
- isomorphism
- bijection
- injection
- surjection
- partition
- quotient
- equivalence-class
- superset
- complement
- negation
- disjunction
- equivalence-relation
- transitivity
- reflexivity
- antisymmetry
- irreflexivity
- totality
- ordering
- lattice
- graph
- vertex
- edge
- path
- trail
- circuit
- connectedness
- centrality
- betweenness
- closeness
- degree
- community
- detection
- contagion
- cascade
- reinforcement
- balancing
- homeostasis
- self-organization
- decentralisation
- decentralization
- cooperation
- competition
- bargaining
- arbitration
- reconciliation
- legitimacy
- authority
- sovereignty
- jurisdiction
- citizenship
- governance
- participation
- consultation
- agency
- freedoms
- sustainability
- intergenerational
- ethics
- virtue
- courage
- sincerity
- tolerance
- diversity
- belonging
- recognition
- privacy
- publicity
- openness
- discretion
- accountability-gap
- oversight
- supervision
- scrutiny
- dialectic
- synthesis
- antithesis
- thesis
- ideology
- metaphysics
- philology
- lexicography
- lexicology
- metalinguistics
- metalanguage
- self-reflection
- consciousness
- qualia
- perception
- sensation
- affect
- volition
- attention
- simplification
- reductionism
- holism
This curated list is for guided conceptual enrichment, not a developmental milestone or memorisation requirement.
A word can change the question
Imagine two students reading the same claim. One asks whether it is true; the other asks how anyone could know. The difference is not vocabulary difficulty but the question each word allows them to formulate.
Abstraction and its boundaries
Abstraction keeps a meaningful relationship while leaving some detail behind. It helps a learner move from a specific case to a wider principle, but it also requires asking which details cannot safely be ignored.
How to grow an idea
Begin with a clear example, compare a contrasting case, then change the setting. Ask what still holds and what fails. When a comparison breaks, revise the boundary rather than forcing every example to fit.
The geography of meaning
Words can behave differently in a laboratory, courtroom, classroom and family conversation. Ask what the setting contributes to the meaning and what kind of evidence is appropriate there.
The history of meaning
Terms develop across generations and disciplines. An idea can gain new associations as people encounter new technologies and social conditions. Ask how an earlier speaker might have used the term.
Culture and perspective
A word can carry assumptions about respect, authority, fairness or responsibility. Listen to how different communities use it, while separating cultural interpretation from verifiable factual claims.
Knowledge as a network
Connect a word to its premises, examples, contrasts, implications and limitations. Draw arrows and test whether the links are justified. A network of relationships is more useful than isolated definitions.
Reasoning from evidence
Choose a claim from a reliable article. Identify the observation, inference and conclusion. Ask what additional information would strengthen or weaken the argument.
When analogies mislead
A model or metaphor can illuminate an unfamiliar problem without proving anything about it. Identify the shared structure and at least one important difference.
A practical dialogue
Choose a disputed but age-appropriate question. Let each participant explain a position fairly, identify an assumption and ask a sincere question. The aim is understanding before judgement.
A week of transfer
Find a word in context, compare another use, identify a counterexample, draw a concept map, apply the idea to a new subject, test it and explain how your understanding changed.
The larger purpose
Vocabulary enables precise thought, curiosity and respectful disagreement. A young person grows when they can use language to recognise relationships, revise beliefs and navigate unfamiliar situations.