Using Coh-Metrix Temporal Indices to Predict Psychological Measures of Time

Using Coh-Metrix Temporal Indices to Predict Psychological Measures of Time Nicholas D. Duran (nduran@memphis.edu) Phillip M. McCarthy (pmccarthy@memphis.edu) Arthur C. Graesser (a-graesser@memphis.edu) Danielle S. McNamara (dsmcnamr@memphis.edu) Institute for Intelligent Systems Department of Psychology 202 Psychology Building Memphis, TN 38152 USA One of the benefits of the tool has been its ability to assess textual cohesion. Cohesion explicitly connects linguistic constituents, propositions, conceptual themes and sub-themes, thereby assisting the reader in generating inferences and bridging conceptual gaps (e.g., McNamara, 2001). Differences in cohesion within a text can be correlated with the coherence of a reader’s interpretation of a text. In other words, cohesion as a textual construct can be mapped onto coherence as a psychological construct. However, while the effects of coreference cohesion indices such as argument overlap (Kintsch & van Dijk, 1978) and LSA (Foltz, Kintsch, & Landauer, 1998) have been well-tested, there has not been the same focus on whether temporal indices of cohesion are able to distinguish relevant temporal themes and sub-themes that contribute to coherence. The purpose of this study is to extend the work of Coh-Metrix into the temporal aspect of cohesion. Specifically, we analyze a corpus of narrative, history, and science texts to ascertain the degree to which temporal cohesion indices predict human derived psychological measures of temporality. Abstract Situation model theories of text comprehension consider temporality to be one of the critical dimensions for building a coherent mental representation of described events. Using this framework, three continuous scale measures were developed to assess temporal coherence based on tense, aspect, and adverbial relations. Experts in discourse processing evaluated 150 texts, excerpted from science, history, and literature textbooks, to establish a gold standard of temporality. We then demonstrated that Coh-Metrix, a computational tool that measures textual cohesion on over 200 indices of discourse features, could significantly reflect these human interpretations by incorporating five indices of local, temporal cohesion. We conclude our paper with a discussion of our current research into developments of more sophisticated global temporal indices. Introduction Three grammatical devices primarily establish temporal relations in text: tense, aspect, and adverbial elements (Klein, 1994). These linguistic markers are not only important for the structure of discourse, but also facilitate the mental representations of situations described in language (Zwaan & Radvansky, 1998). The markers function as instructions for integrating the interaction of entities, properties, and actions into a coherent mental model of comprehension. Temporal cues, along with other dimensions of situation models (e.g., space, causation, intentionality, and protagonist), also foreground relevant information in a reader’s interpretation of described events (Zwaan, Langston, & Graesser, 1995). While such research has contributed significantly to our understanding of situation model construction, computational limitations have restricted empirical research to relatively short passages of manipulated text. Advances in technology, however, now allow large corpora to be indexed to mark the presence of grammatical and lexical features assumed to play important roles in situation model construction. Graesser et al. (2004) have integrated these text-based linguistic features, as well as other indices of readability and vocabulary, into a web-based software tool called Coh-Metrix (for additional information, visit cohmetrix.memphis.edu). Temporal Measures To establish a psychological gold standard for temporal cohesion, we developed three distinct, continuous scale measures. The measures are motivated by theories of situation models that propose that comprehenders make use of linguistic cues, such as tense, aspect, and adverbs to construct temporal dimensions within their mental models (Graesser, McNamara, & Louwerse, 2003; Graesser, Singer, & Trabasso, 1994; Zwaan & Radvansky, 1998). Grammatical tense, for instance, assists a reader in organizing events along a timeline. Specifically, tense establishes the time of occurrence for an event around a referential point, such as time of utterance. The resulting temporal structure, that places events and actions within the text along a continuum, affects the activation of information in working memory. For example, Carreiras et al. (1997) manipulated tense to allow associations between a character and a job description to be applied in the present (e.g., Marta now works as an economist) or separated by a lapse in time (e.g., Marta in the past worked as an economist). The recall