The role of semantic transparency in the processing of English compound words.

Experiment 1 examined whether the semantic transparency of an English unspaced compound word affected how long it took to process it in reading. Three types of opaque words were each compared with a matched set of transparent words (i.e. matched on the length and frequency of the constituents and the frequency of the word as a whole). Two sets of the opaque words were partially opaque: either the first constituent was not related to the meaning of the compound (opaque-transparent) or the second constituent was not related to the meaning of the compound (transparent-opaque). In the third set (opaque-opaque), neither constituent was related to the meaning of the compound. For all three sets, there was no significant difference between the opaque and the transparent words on any eye-movement measure. This replicates an earlier finding with Finnish compound words (Pollatsek & Hyönä, 2005) and indicates that, although there is now abundant evidence that the component constituents play a role in the encoding of compound words, the meaning of the compound word is not constructed from the parts, at least for compound words for which a lexical entry exists. Experiment 2 used the same compounds but with a space between the constituents. This presentation resulted in a transparency effect, indicating that when an assembly route is 'forced', transparency does play a role.

The effects of root frequency, word frequency, and length on the processing of prefixed English words during reading.

Two experiments were performed to investigate the roles of root morpheme frequency and word frequency in the encoding of prefixed words in sentence context. Two alternative words, which were equated on other indices but differed with respect to either root morpheme frequency or word frequency, were embedded in the same sentence frame. In Experiment 1, there was a significant root morpheme frequency effect on gaze duration but only a marginal word frequency effect. Post hoc analyses indicated that word length influenced both effects, with word frequency effects predominating for shorter words and root morpheme effects predominating for longer words. In Experiment 2, word length was also manipulated. There was a significant root frequency effect for longer prefixed words and a significant word frequency effect for shorter prefixed words. The results were best explained by a dual-route model (with competing whole-word access and compositional routes), in which increasing word length inhibited the whole-word process, relative to the compositional route.