Measuring Individual Differences in Word-Meaning Disambiguation

Accessing appropriate meanings of ambiguous words (e.g., internal vs. musical organ) requires the use of context – a skill likely characterised by individual differences. We aimed to develop a reliable measure of disambiguation skill. In a repeated-measures design (Experiment 1), young adults (N= 197) performed a story-picture matching task. Three-sentence stories ended with a homonym (e.g., “organ”), which was weakly disambiguated towards a subordinate meaning. Responses were slower and less accurate compared to (1) a counterbalanced condition which replaced each ambiguous with a matched unambiguous word (e.g., “piano”), and (2) a different set of unambiguous stories matched to the ambiguous set on psycholinguistic variables. In an individual-differences design (Experiment 2), all participants (N=242, aged 18-60) received the same Ambiguous and set-matched Unambiguous items in the same order. Group-level ambiguity effects were replicated but effect size varied by individual. We calculated accuracy and response time scores for each individual: difference scores of condition averages and slope scores from trial-level data. Scores showed split-half-reliabilities of r =.41 -.65. They were neither consistently correlated with each other, nor with other linguistic and cognitive tasks. Although our task captured variability in disambiguation skill, results highlight the non-triviality of turning group-level paradigms into individual-difference measures.