The construction of large number representations in adults

What is the nature of our mental representation of quantity? We find that human adults show no performance cost of comparing numerosities across vs. within visual and auditory stimulus sets, or across vs. within simultaneous and sequential sets. In addition, reaction time and performance in such tasks are determined by the ratio of the numerosities to be compared; absolute set size has no effect. These findings suggest that modality-specific stimulus properties undergo a non-iterative transformation into representations of quantity that are independent of the modality or format of the stimulus.     

Parental language and verbal responsiveness to children in crowded homes.

This article is a secondary data analysis of the University of Kansas Language Acquisition Project, which intensively studied, on a regular basis, parent and child language from age 6 months to 30 months. The association between residential density and parent-child speech was examined. Parents in crowded homes speak in less complex, sophisticated ways with their children compared with parents in uncrowded homes, and this association is mediated by parental responsiveness. Parents in more crowded homes are less verbally responsive to their children. This in turn accounts for their simpler, less sophisticated speech to their children. This mediational pathway is evident with statistical controls for socioeconomic status. This model may help explain prior findings showing a link between residential crowding and delayed cognitive development.     

A conservative inverse normal test procedure for combining p-values in integrative research

The use ofp-values in combining the results of independent studies often involves studies that are potentially aberrant either in quality or in actual values. A robust data analysis suggests the use of a statistic that takes these aberrations into account by trimming some of the largest and smallestp-values. We present a trimmed statistic based on an inverse cumulative normal transformation of the orderedp-values, together with a simple and convenient method for approximating the distribution and first two moments of this statistic.The author thanks Ingram Olkin, David Rogosa, Jim Hodges and two anonymous reviewers for providing many useful comments and suggestions.     

A glass rodent enclosure: Gerbil City

A glass housing unit for the study of rodent burrowing behavior is described. The results of 18 months of burrowing for a family ofMeriones unguiculatus are depicted. The system can be used to investigate relationships among the animals’ behaviors, communication processes, and ecology.     

Long-term memory and retrieval at ages 2, 3, 4

Two experiments are reported examining the contents and accessibility of a subset of the knowledge represented in long-term memory by very young children. In Experiment 1, children aged 2 to 4 were asked in a production task to name items commonly found in particular rooms in a house, and then to verify the appropriate locations of a set of miniature replicas of household items in a dollhouse. In Experiment 2, object context was manipulated to observe if further external context improves or changes production. Children 3 and 4 years old were asked to produce appropriate room items under one of three conditons: either presented no room objects as in the first experiment, or given room objects highly- or less-frequently associated in the first study.Very young children revealed considerable knowledge in this domain, and even at the youngest ages, core defining information was retrieved. It was equally clear, however, that young children know much more than they can produce, that there is noticeable improvement in ability to retrieve information over this age range, and that additional external object context does not necessarily facilitate retrieval from long-term memory.     

Masking disrupts recovery of location information

In two experiments, we tested subjects’ ability to localize a letter in a character string with identification controlled by varying the delay of a mask, dimming the display, or deleting some of the dots used to define the letters on the cathode-ray screen. The first experiment involved two tasks. In the first task, subjects indicated whether or not a letter named verbally had been present in an eight-letter target string. In the second task, they localized a letter named verbally in the target string; the target string was presented by using display parameters shown in the first task to hold character identification between 70% and 75% correct. In the second experiment, we tallied errors in a partial-report bar-probe study after equating performance across the manipulations of display quality. Masking disrupted subjects’ ability to recover location information more than either a manipulation of stimulus luminance or a manipulation of its visual form.     

Rank disagreement: A comparison of multi-criteria methodologies

A number of multi-criteria decision support techniques have emerged in recent years that use varying computational approaches to arrive at the most desirable solution and thereby ‘recommend’ a course of action. Decision makers who use the results of this analytic work should be assured that the computational schemes used by their supporting analysts or decision support software produce the appropriate solutions. We conducted a series of simulation experiments that compared the top-ranked options resulting from the computational algorithms that support Multi-Attribute Value Theory (MAVT) and three methods that are reported in the literature that allow rank reversals, the change in rank order of two options when an unrelated option is added or deleted from the analysis: the Analytical Hierarchy Process (AHP), Percentaging and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). We also included a Fuzzy algorithm proposed by Yager to gauge its consistency with the other algorithms, even though it is not subject to rank reversals. These experiments demonstrated that the MAVT and AHP techniques, when provided with the same decision outcome data, very often identify the same alternative as ‘best’. The other techniques are noticeably less consistent with MAVT, the Fuzzy algorithm being the least consistent. The situations under which the most frequent and significant differences occurred were dependent upon the method. The results of our experiments indicate that other issues (e.g. the processes used for problem structuring and the elicitation of value weights) are likely to be of greater significance to problem outcome (based on our experience) than the choice between the computational algorithms of MAVT and AHP. The results cause us to be concerned about the use of the other methods.