On the role of imagery in linear syllogistic reasoning

Summary The functional role of imagery in linear syllogistic reasoning has not yet been convincingly established. Shortcomings of previous theories and research are discussed. A conceptual analysis of the imagery position leads to the differentiation of modality-specific, analogical-representational, and process perspectives. To obtain evidence relevant to the first and third of these perspectives, a Stroop-type interference paradigm was used in combination with self-paced successive presentation of task components (premises and question of linear syllogisms). Effects of interference information and task components upon response time were consistent with the process reconceptualization of the imagery position.     

Ratings of Orally Presented Verbal Expressions of Probability by a Heterogeneous Sample

Verbal expressions of probability are used in daily conversations, physician-physician and physician-patient communications, and questionnaire and interview responses. To assess the degree of agreement among English-speaking Australian adults in allocating numerical probabilities to these verbal expressions of probability, 966 interviewees provided estimates for 60 isolated expressions of probability and a sequence of seven items placed in a sequence. Means and median scores appeared to be consistent with common sense and with findings from other countries. Mirror-imaged terms were neither symmetrical nor equidistant, with the means and medians for the positive terms being closer to the mid-points of the scale than the means and medians of the negative terms. Items in a sequence of probability terms showed greater symmetry and less variability than isolated expressions. For most items, there was an unacceptably high level of within-subject and between-subject variability. Although subjects with higher levels of education and/ or mathematics education showed less variability, these factors accounted for very little of the variance. The greater variability in Australian results relative to those reported elsewhere was partly attributed to the use of interviews rather than questionnaires. There were no particular stems that yielded greater consistency. It was concluded that the use of these expressions leads to very imprecise communication.