Summation and transfer of negative occasion setting

Two experiments examined the summation and transfer of negative occasion setting in serial feature negative (X→A?/A+) and negative patterning discriminations (X→A?/X+/A+) in a discrete-trial operant task with rats. With both discrimination procedures, negative occasion setting transferred readily (but not perfectly) to cues trained as targets in another similar discrimination procedure, but not to cues that were separately trained. Furthermore, with both discrimination procedures, the negative occasion-setting powers of features from two individual discriminations summed, both when those features were trained with the same targets and when they were trained with different targets. After negative patterning discriminations, in which the feature (X) cues were separately reinforced, this summation of negative occasion setting occurred despite the concomitant summation of the features’ excitatory control in the absence of an explicit target cue. These data, which replicated and extended previously reported data from Pavlovian feature negative procedures, are discussed in the context of hierarchical, generalization, and network models of discrimination learning.     

An Approach to Evaluating the Missing Data Assumptions of the Chain and Post-stratification Equating Methods for the NEAT Design

Two important types of observed score equating (OSE) methods for the non-equivalent groups with Anchor Test (NEAT) design are chain equating (CE) and post-stratification equating (PSE). CE and PSE reflect two distinctly different ways of using the information provided by the anchor test for computing OSE functions. Both types of methods include linear and nonlinear equating functions. In practical situations, it is known that the PSE and CE methods will give different results when the two groups of examinees differ on the anchor test. However, given that both types of methods are justified as OSE methods by making different assumptions about the missing data in the NEAT design, it is difficult to conclude which, if either, of the two is more correct in a particular situation. This study compares the predictions of the PSE and CE assumptions for the missing data using a special data set for which the usually missing data are available. Our results indicate that in an equating setting where the linking function is decidedly non-linear and CE and PSE ought to be different, both sets of predictions are quite similar but those for CE are slightly more accurate .     

Visual reinforcement: Operant acquisition in the presence of a free mirror

In Experiment I Siamese fighting fish performed operant responses that produced a mirror image to which the fish could display; consistent detectable display was not necessary for maintenance of operant performance. In Experiment II fish acquired and continued to perform an operant response that produced a mirror, although a “free” mirror was continually present; display rate to the contingent mirror increased while display rate to the “free” mirror was decreasing. An interpretation of these and previous data in terms of sensory reinforcement is suggested.     

Teaching practices in Grade 5 mathematics classrooms with high-achieving English learner students

Teachers need more clarity about effective teaching practices as they strive to help their low-achieving students understand mathematics. Our study describes the instructional practices used by two teachers who, by value-added metrics, would be considered “highly effective teachers” in classrooms with a majority of students who were English learners. We used quantitative data to select two fifth-grade classrooms where students, on average, made large gains on a mathematics achievement test, and then examined teaching practices and contextual factors present in each classroom. Participants included two teachers from a mid-Atlantic district and their students who were 67% English learners and 68% economically disadvantaged. We found that the use of multiple representations of mathematics concepts, attention to vocabulary building, individual and group checks for understanding and error analysis were prevalent practices in both high gains classrooms. Also, class sizes ranged from 12–19 students. Discussion focuses on whether observed practices are aligned with recommended teaching practices for English learner students.     

Measuring the Benefits of Examinee-Selected Questions

Allowing students to choose the question(s) that they will answer from among several possible alternatives is often viewed as a mechanism for increasing fairness in certain types of assessments. The fairness of optional topic choice is not a universally accepted fact, however, and various studies have been done to assess this question. We examine an important class of experiments that we call C1-A, "choose one, answer all," designs, and point out an important problem that they face. We suggest two analytical methods that can be used to circumvent this problem. We illustrate our ideas using the data from Bridgeman et al. (1997) . Our reanalysis of these data show: (a) that differential topic difficulty exists in real choice data, (b) that it affects naïve analyses of such data and masks the effects, positive or negative, of examinee choice, (c) that in this study there is a measurable and positive effect of examinee choice that follows predicted patterns in most but not all cases, (d) that the beneficial strength of examinee choice varies from case to case, and (e) that while the benefits of choice in terms of average points scored on the essays are usually positive, there is a substantial amount of variation around these averages and it is not uncommon for "incorrect" choices to be associated with higher test performance.     

A Classroom Demonstration of Hypothesis Testing

This article describes a classroom demonstration that may be used to encourage students’ development and understanding of the idea of hypothesis testing.