Multiple-pair training enhances transposition in pigeons

We studied transposition in pigeons by training them to select the smaller (or the larger) of a pair of circles. In training, different groups of pigeons were given one pair, two pairs, or three pairs of circles along the size dimension. Testing included two stimulus pairs for which, according to theoretical postdiscrimination generalization gradients, transposition should decrease from one-pair to two-pair to three-pair training. On the basis of the results of our earlier study (Lazareva, Wasserman, & Young, 2005) and contrary to these predictions, we expected that transposition should increase from one-pair to two-pair to three-pair training. We found that multiple-pair discrimination training enhanced transposition, which, on average, rose from 47% (one-pair training) to 52% (two-pair training) to 64% (three-pair training). In addition, we found that the overall similarity of the testing pair to the training pair(s) modulated the strength of relational responding. These results demonstrate that encountering multiple instances of a rule leads to stronger relational learning, even when reinforcement history predicts the opposite trend. These results also provide strong evidence against stimulus generalization as the sole determinant of relational responding in transposition.     

The acquisition of trace supraordinate stimulus control in pigeons

Match-to-sample and oddity-from-sample problems with four colors were acquired by two pigeons under the supraordinate control of a line tilt superimposed on samples, Since the supraordinate stimulus terminated before the comparison stimuli were presented, accurate matching and oddity performance indicated trace stimulus control as well, The temporal extent of trace control was assessed in one subject by presenting probes—trials without a line tilt on the sample—in which the basis of correct responding was the supraordinate stimulus presented on the previous trial, Trace supraordinate control did not extend between trials, Subsequently, the delay between the termination of the supraordinate stimulus and the presentation of the comparison stimuli was gradually increased within a trial, Both subjects were able to perform matching and oddity over longer delays, and eventually on probe trials, although accuracy decreased, Results were discussed in terms of instructional stimulus control and memory.     

Community‐based literacy learning

Because reading and writing are social as well as personal activities, many recent curricular reforms that promote literacy development have focused on the relationship between the learner and the community. These reforms have been based on situated cognition theory, which holds that learning is intermeshed with the social and physical contexts of activity and that learning occurs through active participation in a community of practice. Yet there is no distinct orientation to the concept of community across the various educational programs. In fact, at least three different orientations to community appear in the literature on literacy reform: experiential community, classroom community, and anticipatory community. Both experiential and anticipatory community orientations situate literacy in non‐school settings that involve learners in ‘real‐life’ communities. The classroom community orientation attempts to reproduce the roles of mentor and apprentice found in non‐school communities; however, its claim to legitimacy of activity is based more on the learner’s manner of participation than in the activity itself.     

Meeting the Access Challenge: An Examination of Indiana's Twenty-First Century Scholars Program

Early intervention programs can promote access by providing encouragement for academic preparation, but adequate grant aid may be necessary to ensure access for students who prepare. This study examines the impact of Indiana's Twenty-first Century Scholars Program, an intervention that provides supplemental grant aid and academic support for low-income middle and high school students. Hierarchical logistic regression analyses indicated that 8th grade students who participated in the program were more likely to apply than their peers, indicating that encouragement had a modest influence on preparation. Receiving grant aid had a substantial influence on enrollment, indicating adequate aid is an important aspect of a comprehensive postsecondary encouragement program.     

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Letters

Professor ellis responds     

An educational technology curriculum for converging technologies

In the 1990s, digital encoding will cause different modalities for presenting information to converge. These convergent technologies will require a new kind of educational designer and a realignment of graduate programs. Curriculum revision efforts should address the commonalities inherent in convergent technologies and should incorporate emerging design tools, procedures, and principles. This article reviews issues related to converging technologies and describes how they are affecting the Educational Technology curriculum at San Diego State University.     

The Development of Category-based Induction

In a category-based induction, knowing that a property is true of some category members leads one to conclude that the property is true of other category members. An example is: Cardinals have ulnar arteries. Therefore hawks have ulnar arteries. Recently, Osherson et al. (1990) demonstrated a number of phenomena involving category-based inductions, and proposed that these phenomena can be explained by variations in 2 processes: (a) the similarity between the premise category (cardinals in the above example) and the conclusion category (hawks in the above example), and (b) the degree to which the premise category "covers" (roughly, is similar to) instances of the lowest-level category that includes both the premise and conclusion categories (birds in the above example). The present paper traces the developmental course of the relevant phenomena and of the similarity and coverage processes that presumably underlie them. Studies 1 and 2 demonstrated that the inductions made by kindergartners are sensitive only to the similarity between the premise and conclusion categories. Studies 3 and 4 showed that second graders' inductions are sensitive to both premise-conclusion similarity and coverage, as long as there is no need actually to use a generated category that includes both the premise and conclusion categories. These developmental findings reveal an orderly process in the growth of category-based inductions, and also decompose the Osherson et al. model into 3 basic components that have not previously been explicitly distinguished.     

“What is a good digital library?” – A quality model for digital libraries

In this article, we elaborate on the meaning of quality in digital libraries (DLs) by proposing a model that is deeply grounded in a formal framework for digital libraries: 5S (Streams, Structures, Spaces, Scenarios, and Societies). For each major DL concept in the framework we formally define a number of dimensions of quality and propose a set of numerical indicators for those quality dimensions. In particular, we consider key concepts of a minimal DL: catalog, collection, digital object, metadata specification, repository, and services. Regarding quality dimensions, we consider: accessibility, accuracy, completeness, composability, conformance, consistency, effectiveness, efficiency, extensibility, pertinence, preservability, relevance, reliability, reusability, significance, similarity, and timeliness. Regarding measurement, we consider characteristics like: response time (with regard to efficiency), cost of migration (with respect to preservability), and number of service failures (to assess reliability). For some key DL concepts, the (quality dimension, numerical indicator) pairs are illustrated through their application to a number of “real-world” digital libraries. We also discuss connections between the proposed dimensions of DL quality and an expanded version of a workshop’s consensus view of the life cycle of information in digital libraries. Such connections can be used to determine when and where quality issues can be measured, assessed, and improved – as well as how possible quality problems can be prevented, detected, and eliminated.     

Attributes of effective and efficient kindergarten reading intervention: an examination of instructional time and design specificity

A randomized experimental design with three levels of intervention was used to compare the effects of beginning reading interventions on early phonemic, decoding, and spelling outcomes of 96 kindergartners identified as at risk for reading difficulty. The three instructional interventions varied systematically along two dimensions--time and design of instruction specificity--and consisted of (a) 30 min with high design specificity (30/H), (b) 15 min with high design specificity plus 15 min of non-code-based instruction (15/H+15), and (c) a commercial comparison condition that reflected 30 min of moderate design specificity instruction (30/M). With the exception of the second 15 min of the 15/H+15 condition, all instruction focused on phonemic, alphabetic, and orthographic skills and strategies. Students were randomly assigned to one of the three interventions and received 108 thirty-minute sessions of small-group instruction as a supplement to their typical half-day kindergarten experience. Planned comparisons indicated findings of statistical and practical significance that varied according to measure and students' entry-level performance. The results are discussed in terms of the pedagogical precision needed to design and provide effective and efficient instruction for students who are most at risk.