Vocabulary test format and differential relations to age

Abstract

Although vocabulary tests are generally considered interchangeable, regardless of format, different tests can have different relations to age and to other cognitive abilities. In this study, 4 vocabulary test formats were examined: multiple-choice synonyms, multiple-choice antonyms, produce the definition, and picture identification. Results indicated that, although they form a single coherent vocabulary knowledge factor, the formats have different relations to age. In earlier adulthood, picture identification had the strongest growth, and produce the definition had the weakest. In later adulthood, picture identification had the strongest decline, and multiple-choice synonyms had the least. The formats differed in their relation to other cognitive variables, including reasoning, spatial visualization, memory, and speed. After accounting for the differential relations to other cognitive variables, differences in relation to age were eliminated with the exception of differences for the picture identification test. No theory of the aging of vocabulary knowledge fully explains these findings. These results suggest that using a single indicator of vocabulary may yield incomplete and somewhat misleading results about the aging of vocabulary knowledge.

Figure 1

Relation between age and z-scores on the vocabulary tests.

Figure 2

Relation between item difficulty and point-biserial correlations between age and items scores. Each point represents a single item.

Figure 3

Structural equation measurement model. Indicators on the broad cognitive ability factors are suppressed.

Figure 4

Abbreviated path models of relation between cognitive abilities and vocabulary formats. Numbers and the thickness of the lines connecting to vocabulary tests represent standardized regression coefficients.