A variation of the Raaijmaker and Shiffrin (1981) retrieval model is proposed to account for typical script generation data. In our model, knowledge is represented as an associative network with propositions as the nodes. A control process which utilizes temporal information in these propositions supplements the probabilistic memory retrieval process to produce ordered retrieval of scriptal events. Simulations are reported which provide a good qualitative fit to data collected from subjects in both script generation and free association tasks. These results support a view of memory as an unorganized knowledge base rather than a stable, organized structure

We compare the effects of interrupting text dealing with familiar or unfamiliar domains with either arithmetic or sentence reading tasks. Readers were interrupted after each of the eight sentences, at the end of each sentence, or in the middle of each sentence. Previous findings of minimal effects of interruptive tasks on comprehension measures (eg . fllanzer & Nolan, 1986) were replicated in this study. Also, as found by Glanzer and his colleagues, interruptions after each sentence of a familiar text by an unrelated sentence increased reading times by approximately 400 ms per sentence. In contrast, for difficult, unfamiliar texts, mid-scnience interruptions significantly lengthened reading times by 1262 ms for sentence and 1784 ms for arithmetic interruptions. These findings arc explained in terms of Enesson and Kintsch's (1995) memory model which proposes that skilled memory performance relies on the use of long-term memory as an extension of working memory, or long-term working memory.