Verb Form Indicates Discourse Segment Type in Biological Research Papers: Experimental Evidence

Corpus studies suggest that verb tense is a differentiating feature between, on the one hand, text pertaining to experimental results (involving methods and results) and on the other hand, text pertaining to more abstract concepts (i.e. regarding background knowledge in a field, hypotheses, problems or claims). In this paper, we describe a user experiment that investigates whether for biological readers, this tense correlation has a psychological correlate. To study this, we defined seven distinct discourse segments types and modified them either by changing the verb tense/mood (for all segment types), negation (for Problems), or presence of an epistemic matrix clause ("These results suggest...") for Implications. Regardless of the original segment type, we found that for Facts, Results and Hypothesis segments, present tense yielded more Fact classifications, past tense more Result interpretations, and modal auxiliaries more Hypothesis interpretations. Methods statements were less sensitive to verb form. Problem segments required negations to be recognized, while Implications required introductory matrix clauses. (Contains 1 figure and 11 tables.)