No abstract

Whether the process of lexical access in silent reading is mediated by an internal phonological representation or only by visual representations has been a topic of empirical investigation since before the turn of the century. To date, research has generated contradictory findings. More recent evidence suggests that factors such as difficulty of material, frequency of occurrence of items, subjects' fluency, and task demands-which are seldom manipulated in typical studies of word recognition-play important roles in determining the type of mediation used. As a result, interest has shifted to a family of dual access models in which both phonological mediation and visual mediation are ordinarily used in parallel. The data point to a dual access model in which high-frequency words enjoy highspeed access via a visually based representation, whereas low-frequency words are accessed using a slower, phonological receding process.

Recent studies have demonstrated that two-word lexical decision times may be influenced by the degree of shared phonemic and graphemic similarity between the items. Specifically, graphemically similar rhyming pairs (e.g., BRIBE-TRIBE) are responded to more rapidly than graphemically and phonemically unrelated controls (e.g., BREAK-DITCH), whereas graphemically similar nonrhyming pairs (TOUCH-COUCH) are responded to more slowly. In a series of three experiments, the present study examined the encoding-bias explanation (Meyer, Schvaneveldt, & Ruddy, 1974) of these effects by modifying or eliminating the graphemic information available. Experiment 1 found that rhyming facilitation was not eliminated by presenting the initial pair member auditorily. Experiments 2 and 3 showed the rhyming effect to be independent of graphemic similarity with equivalent facilitation for graphemically similar and dissimilar (EIGHT-MATE) rhymes. These findings were all considered contrary to the predictions of the encoding-bias model. As an alternative, a model by Forster (1976) was employed. In the Forster model, sensory representations of lexical entries are represented as entries in a separate access file organized by physical, rather than semantic, similarity. The rhyming facilitation can then be seen as the result :>f spreading activation between entries in this file.

Bransford and Franks (1971) introduced a paradigm for the study of linguistic integration. Their primary measure was subjects' rated confidence in their responses. The present paper considers the appropriateness of this dependent variable, and concludes that the relation between sentence complexity and rated confidence is too small and unstable to justify the emphasis which confidence ratings have received. Further, certain differences between concrete and abstract sentences were obscured by a confidence analysis. The proportion of old responses is championed as a more appropriate dependent variable. Finally, it is shown that increasing the amount of specific memory necessarily decreases the size of the complexity effect.There is growing literature concerned with the issue of linguistic integration, primarily stimulated by the work of Franks (1971, 1973; Franks & Bransford, 1972 In acquisition, sentences derived from each of several fours are presented, usually under a procedure not encouraging memorization of form. During recognition, both old and new sentences are tested. (New sentences are permissable combinations of ideas derivable from the four which were not presented during acquisition.) Subjects are required to label each recognition sentence as "old" or "new" and to assign a confidence rating to their categorizations. Bransford and Franks (1971) reported two facts of primary interest: Confidence ratings (CRs) increased sharply with complexity of the recognition sentence, and the functions for olds and news were quite similar; ratings for new ones were lower than for old ones, but otherwise it appeared that subjects could not distinguish olds from news. Bransford and Franks concluded that the complex idea was abstracted from the exemplars, no traces of which were retained. Hence, olds and news were indistinguishable, and the closer

While hypermedia can provide flexible and rapid access to information in multiple mediums its navigation can be daunting to an unfamiliar user. This paper describes a prototype hypermedia system for training the components of a turbine engine. Designed as a content-rich hypermedia substrate combined with an independent guide, the system provides the novice with structure without impeding exploration. Results of a comparative study indicate that users unfamiliar with the topic learn more when the guide is available while users already comfortable with turbine concepts learn targeted information better without the guide.