Francis T. Durso

Network Structures in Proximity Data

Publisher Summary This chapter discusses network representations and their relationship to proximity data. Proximity data are commonplace in the social and behavioral sciences. Networks have several properties that should be of value in representing the structure in proximity data. Networks reduce a large number of pairwise proximities to a smaller set of links. Compared to spatial scaling methods, networks focus on the closely related entities. Graph theory is the mathematical study of structures consisting of nodes with links connecting some pairs of nodes. In applications of networks, the nodes usually represent entities and the links represent pairwise relations among the entities. Because a set of nodes can be connected by links in many possible ways, a wide variety of structures can be represented by graphs. The methods used to obtain the proximity data used in the Pathfinder analyses are straightforward and analogous to methods employed to obtain data for cluster analysis

Measuring the structure of expertise

This report reviews work on defining and measuring conceptual structures of expert and novice fighter pilots. Individuals with widely varying expertise were tested. Cognitive structures were derived using multidimensional scaling (MDS) and link-weighted networks (Pathfinder). Experience differences among pilots were reflected in the conceptual structures. Detailed analyses of individual differences point to factors that distinguish experts and novices. Analysis of individual concepts identified areas of agreement and disagreement in the knowledge structures of experts and novices. Applications in selection, training and knowledge engineering are discussed.

The effects of orienting tasks on recognition, recall, and modality confusion of pictures and words

Subjects were presented with a list of pictures and words and performed tasks that oriented processing toward the concept as an image, the concept as a verbal item, or toward underlying referential information associated with the concept. Recognition (Experiment 1) for concepts presented as pictures was superior only when the task required subjects to orient to the concept as a verbal item per se; a word superiority effect was observed when orientation was to the concept as a picture per se. The mode of presentation did not influence concept recognition when subjects had focused on the referential meaning of the items. Memory for form was also influenced by the task, with subjects more likely to claim they saw a word as a picture than vice versa, but only in the referent tasks. When subjects were asked to recall, rather than recognize the concepts (Experiment 2), there was a similar, though not identical, pattern of results. The sensory-semantic model of D. L. Nelson, V. S. Reed, and C. L. McEvoy Journal of Experimental Psychology: Human Learning and Memory, 1977, 3, 485–497) had difficulty with some aspects of these data. The availability of information regarding cognitive operations performed on the input seems to be an important component of memory traces.

Individual differences in working memory capacity predict visual attention allocation

To the extent that individual differences in working memory capacity (WMC) reflect differences in attention (Baddeley, 1993; Engle, Kane, & Tuholski, 1999), differences in WMC should predict performance on visual attention tasks. Individuals who scored in the upper and lower quartiles on the OSPAN working memory test performed a modification of Egly and Homa’s (1984) selective attention task. In this task, the participants identified a central letter and localized a displaced letter flashed somewhere on one of three concentric rings. When the displaced letter occurred closer to fixation than the cue implied, high-WMC, but not low-WMC, individuals showed a cost in the letter localization task. This suggests that low-WMC participants allocated attention as a spotlight, whereas those with high WMC showed flexible allocation.

Effect of schema-incongruent information on memory for stereotypical attributes.

Two studies were performed to determine the effect of incongruent information on recall of schematic information in the domain of person memory. Subjects heard descriptions of five sterotypical characters, followed by additional information varying in level of relevance to, and congruence with, the initial information. We measured free recall of the initial information establishing the schema, which included a stereotype label and two highly congruent facts. Results showed that the introduction of information that is highly incongruent with a schema makes schematic information more memorable, under both immediate- and delayed-recall conditions. This effect may be one mechanism by which inappropriate schemata persevere in the face of counterevidence. The pattern of results is found to be more consistent with Hasties (1980) depth of processing-network associational model of schematic processing (with slight modification) than with Smith and Graessers (1981) schema-pointer + tag model.

Does situation awareness add to the validity of cognitive tests

Objective: Does adding situation awareness (SA) to a battery of cognitive tests improve prediction? Background: Identifying variables that predict skilled performance in a complex task aids in understanding the nature of skill and also aids in the selection of operators to perform that task. SA is thought to be an important predictor of performance. SA is often thought to be based on underlying cognitive mechanisms. Method: Three performance measures taken from the Federal Aviation Administrations (FAAs) Air Traffic Scenarios Test, the low-fidelity simulation component of the FAAs controller selection battery, were used as criterion variables in a hierarchical regression. After predicting performance based on a battery of cognitive (e.g., intelligence, working memory, spatial memory) and noncognitive tests (e.g., cognitive style, personality, demographics), we added measures of SA. Results: SA did provide increases in prediction, but only when measured with the Situation Present Assessment Method, an on-line query method. When the same questions were asked off line, SA did not enter the model in two cases and improved prediction by only 2% in the third. Conclusion: Thus, some measures of SA do show incremental validity, even against a backdrop of a large number of cognitive variables. Application: On-line measures of SA can be a worthwhile addition to standard batteries of tests used to predict performance in cognitively oriented industrial tasks.

Graph theoretic foundations of pathfinder networks

Abstract This paper is primarily expository, relating elements of graph theory to a computational theory of psychological similarity (or dissimilarity). A class of networks called Pathfinder networks (PFNETs) is defined. PFNETs are derived from estimates of dissimilarity for pairs of entities. Thus, PFNETs can be used to reveal aspects of the structure inherent in a set of pairwise estimates of dissimilarity. In order to accommodate different assumptions about the nature of the measurement scale (i.e. ordinal, interval, ratio) underlying the data, the Minkowski r-metric (also known as the L norm) is adapted to computing distances in networks. PFNETs are derived from data by: (1) regarding the matrix of dissimilarities as a network adjacency matrix (the DATANET); (2) computing the distance matrix (or r-distance matrix using the Minkowski r-metric) of the DATANET and (3) reducing the DATANET by eliminating each arc that has weight greater than the r-distance between the nodes connected by the arc. PFNET properties of inclusion, relation to minimal spanning trees, and invariance under transformations of data are discussed.

Developmental comparisons of explicit versus implicit imagery and reality monitoring

Reality Monitoring refers to the decision processes involved in discriminating perceptual memories from those which are self-generated. The present studies compare the effects of spontaneous, implicit imagery generation and controlled, explicit imagery generation on the reality monitoring decisions of children and adults. Subjects (6 year olds, 9 year olds, and adults) were shown pictures and words, and they were asked each objects function or they were asked to create an image of each object. When later deciding whether each object was presented as a picture or a word, subjects were more likely to claim a word was presented as a picture than the converse, especially in the Function condition (Experiment 1). This confusion effect was evident for simple and complex perceptual materials and extended across three age groups (Experiments 1 and 2). The results indicate that the absence of developmental differences in reality monitoring previously reported is not due simply to the type of imagery involved, and that the representational processes of children and adults are more alike than is commonly believed.

Graph-Theoretic Confirmation of Restructuring During Insight:

The “flash of insight” sometimes observed in problem solving and in scientific discovery has been thought to be due to a sudden cognitive restructuring of the problem situation Direct confirmation of restructuring has been difficult without an independent procedure for determining cognitive structure Graph structures were derived from judgments of concept relatedness made by subjects who had an insight and by several groups who either did not or could not have the insight The graphs of the solvers differed from the graphs of subjects who tried and failed, those who listened to the solvers, and those who were given the solution When other subjects in a subsequent experiment repeatedly judged similarity of pairs of concepts, there was evidence that those connections critical to the new cognitive order were targeted long before there was the breathtaking cognitive reorganization

Judging Category Frequency: Automaticity or Availability?

Two explanations of sensitivity to categorical frequency—automatic processing (Hasher & Zacks,1979) and the availability heuristic (Tversky & Kahneman, 1973)—were investigated in two experi-ments. Sensitivity to category frequency was affected by instructions (Experiment I). Varying re-trieval time did not affect frequency sensitivity (Experiment 1), but manipulating encoding time did(Experiment 2). Differences in item recallability tend to support the availability heuristic hypothesisover the hypothesis of automatic processing.