Toward a unified theory of decision criterion learning in perceptual categorization

Optimal decision criterion placement maximizes expected reward and requires sensitivity to the category base rates (prior probabilities) and payoffs (costs and benefits of incorrect and correct responding). When base rates are unequal, human decision criterion is nearly optimal, but when payoffs are unequal, suboptimal decision criterion placement is observed, even when the optimal decision criterion is identical in both cases. A series of studies are reviewed that examine the generality of this finding, and a unified theory of decision criterion learning is described (Maddox & Dodd, 2001). The theory assumes that two critical mechanisms operate in decision criterion learning. One mechanism involves competition between reward and accuracy maximization: The observer attempts to maximize reward, as instructed, but also places some importance on accuracy maximization. The second mechanism involves a flat-maxima hypothesis that assumes that the observer's estimate of the reward-maximizing decision criterion is determined from the steepness of the objective reward function that relates expected reward to decision criterion placement. Experiments used to develop and test the theory require each observer to complete a large number of trials and to participate in all conditions of the experiment. This provides maximal control over the reinforcement history of the observer and allows a focus on individual behavioral profiles. The theory is applied to decision criterion learning problems that examine category discriminability, payoff matrix multiplication and addition effects, the optimal classifier's independence assumption, and different types of trial-by-trial feedback. In every case the theory provides a good account of the data, and, most important, provides useful insights into the psychological processes involved in decision criterion learning.     

Scientific societies and research integrity: What are they doing and how well are they doing it?

Scientific societies can play an important role in promoting ethical research practices among their members, and over the past two decades several studies have addressed how societies perform this role. This survey continues this research by examining current efforts by scientific societies to promote research integrity among their members. The data indicate that although many of the societies are working to promote research integrity through ethics codes and activities, they lack rigorous assessment methods to determine the effectiveness of their efforts. An earlier version of this paper was presented at the AAAS-Office of Research Integrity (ORI) meeting in Washington DC on the theme: “The Role and Activities of Scientific Societies in Promoting Research Integrity” held on April 10–11, 2000.     

Twenty years of experimental philosophy research

This paper reports the first study in the literature that adopts a bibliometric approach to systematically explore the scholarship in the young and fast-growing research field of experimental philosophy. Based on a corpus of 1,248 publications in experimental philosophy from the past two decades retrieved from the PhilPapers website, the study examined the publication trend, the influential experimental philosophers, the impactful works, the popular publication venues, and the major research themes in this subarea of philosophy. It found, first, an overall growing trend in publications in experimental philosophy, encompassing four developmental stages. Second, it found that significant changes in topics of interest have taken place, with some gaining increasing attention, others seemingly going out of fashion, and still others remaining popular constantly. Third, the study identified lists of leading philosophers, frequently cited publications, and popular journals helpful for researchers and newcomers to get a quick start in learning about the field.     

Effects consistent with behavioral contrast during a multiple schedule for discrimination training on mands for attention

This study used a multiple schedule to assess the effects of an S+ or S- in the absence of rules on excessive mand rates with three school-aged children with disabilities and assessed possible contrast effects occurring in conjunction with the intervention. Each of the three participants was exposed to the presence or absence of an S- (black baseball cap). When it was worn, mand approach rates decreased for all three participants; conversely, mand rates increased to twice the baseline rates when the experimenter was not wearing the black baseball cap. Generalization probes conducted for one of the three caregivers showed similar changes when the caregiver wore the cap. Results suggest that effects consistent with positive behavioral contrast occurred with all participants.     

Proliferation of authors on research reports in medicine

Publication in the biomedical literature is important because it is the major pathway by which new concepts and discoveries are disseminated amongst scientists. In the last 30 years there has been a dramatic increase, not only in the volume of publications but in the number of authors per article as well. This paper summarizes the current literature on authorship and its proliferation in medicine. From the literature it becomes clear that for biomedical articles, the mean number of authors increased from 1.7 in 1960 to 3.1 in 1990, and there are indications that this trend is even greater in clinical medicine such that single authorship almost has disappeared. Formal guidelines of who should be considered an author have been set by the International Committee of Medical Journal Editors. There are studies suggesting that not all authors on multiauthor papers fulfill these criteria. Inappropriate multiple authorship leads to dilution of authorship responsibility and unjustified citation in curriculum vitae. Recommendations regarding the prevention of inappropriate authorship are given in this paper. This paper is adapted from a lecture presented to a Symposium on Scientific Integrity, Warsaw, Poland, 23 November 1995. Dr. Drenth is a clinical investigator and resident in internal medicine.     

Natural rates of teacher approval and disapproval in the classroom

Sixteen classroom observational studies were conducted to determine natural rates of teacher verbal approval and disapproval in the classroom. Rates of teacher verbal approval and disapproval were measured by the Teacher Approval and Disapproval Observation Record (TAD) over Grades 1 through 12. Teacher verbal approval rates dropped over grade, with a marked drop after second grade. In every grade after second, the rate of teacher verbal disapproval exceeded the rate of teacher verbal approval. These rates are interpreted in terms of reinforcement theory.     

A case study of expert judgment: Economists' probabilities versus base-rate model forecasts

In this case study of economists' forecasts concerning economic downturn, we examine key issues concerning the psychology of prediction and the controversy surrounding the value of expertise in forecasting. We examine when experts' knowledge promotes forecast accuracy and whether biases found in psychological studies (including underutilization of relevant base rates and tendencies to extreme prediction) occur in these economic forecasts. Experts' forecasts were compared to forecasts derived from base-rate models that relied on the historical frequencies of economic downturns. The performance patterns of the experts and models crossed over the forecast horizon. Experts outperformed models in shorter-term forecasting, whereas models outperformed experts in longer-term forecasting. These results highlight the abilities and limits of experts and models in prediction and the sources of their inaccuracy.