Reviewing Reduction in a Preferential Model‐Theoretic Context

In this article, we redefine classical notions of theory reduction in such a way that model‐theoretic preferential semantics becomes part of a realist depiction of this aspect of science. We offer a model‐theoretic reconstruction of science in which theory succession or reduction is often better—or at a finer level of analysis—interpreted as the result of model succession or reduction. This analysis leads to ‘defeasible reduction’, defined as follows: The conjunction of the assumptions of a reducing theory T with the definitions translating the vocabulary of a reduced theory T′ to the vocabulary of T, defeasibly entails the assumptions of reduced T′. This relation of defeasible reduction offers, in the context of additional knowledge becoming available, articulation of a more flexible kind of reduction in theory development than in the classical case. Also, defeasible reduction is shown to solve the problems of entailment that classical homogeneous reduction encounters. Reduction in the defeasible sense is a practical device for studying the processes of science, since it is about highlighting different aspects of the same theory at different times of application, rather than about naive dreams concerning a metaphysical unity of science.     

Die Natur des Subjektiven: Einige Bemerkungen zu Kutscheras Objektivismus-Kritik

Kutschera's criticism of an objectivist theory of mind is shown to rest on a premise which an objectivist need not accept, namely, that there is a deep metaphysical distinction between the physical and the psychological domain. This premise can be rejected on naturalistic grounds. Referring to the work of Rosenthal, Dennett and Davidson, it is argued that less metaphysically loaded explanations can be given of what is subjective about the mind. This revised version was published online in August 2006 with corrections to the Cover Date.     

Statistical analysis of the bidirectional inconsistency of spelling and sound in French

Recent studies suggest that performance attendant on visual word perception is affected not only by the “traditional” feedforward inconsistency (spelling → phonology) but also by its feedback inconsistency (phonology → spelling). The present study presents a statistical analysis of the bidirectional inconsistency for all French monosyllabic words. We show that French is relatively consistent from spelling to phonology but highly inconsistent from phonology to spelling. Appendixes B and C list prior and conditional probabilities for all inconsistent mappings and thus provide a valuable tool for controlling, selecting, and constructing stimulus materials for psycholinguistic and neuropsychological research. Such large-scale statistical analyses about a language’s structure are crucial for developing metrics of inconsistency, generating hypotheses for cross-linguistic research, and building computational models of reading.     

Visual search for singleton feature targets within and across feature dimensions

Three experiments investigated visual search for singleton feature targets. The critical dimension on which the target differed from the nontargets was either known in advance or unknown—that is, the critical difference varied eitherwithin a dimension oracross dimensions. Previous work (Treisman, 1988) had shown that, while the search reaction time (RT) functions were flat in both conditions, there was an intercept cost for the cross-dimension condition. Experiment 1 examined whether this cost would disappear when responses could be based on the detection ofany (target—nontarget) difference in the display (by requiring a “heterogeneity/homogeneity” decision). The cost remained. This argues that pop-out requires (or involves) knowledge of the particular dimension in which an odd-one-out target differs from the nontargets; furthermore, that knowledge is acquired through the elimination of dimensions not containing a target. In Experiment 2, the subjects had to eliminate (or ignore) one potential source of difference in order to give a positive response (displays could contain a “noncritical” difference requiring a negative response). The result was a comparatively large cost in the within-dimension (positive) condition. This can be taken to indicate that popout as such does not make available information as to the particular feature value in which the target differs from the nontargets. Experiment 3 examined whether search priorities can be biased in accordance with advance knowledge of the likely source of difference. The subjects were found to have a high degree of top-down control over what particular dimension to assign priority of checking to. The implication of the results for models of visual search and selection are discussed.     

Testing the assumptions and interpreting the results of the Rasch model using log-linear procedures in SPSS

This paper shows how to use the log-linear subroutine of SPSS to fit the Rasch model. It also shows how to fit less restrictive models obtained by relaxing specific assumptions of the Rasch model. Conditional maximum likelihood estimation was achieved by including dummy variables for the total scores as covariates in the models. This approach greatly simplifies the specification of the Rasch models. We illustrate these procedures in an analysis of four items selected from the Reiss Premarital Sexual Permissiveness Scale. We found that a modified version of the Rasch model with item dependencies fits the data significantly better than the simple Rasch model. We also found that the item difficulties are the same for men and women, but that the item dependencies are significantly greater for men. Apart from any substantive issues these results raise, the value of this exercise lies in its demonstration of how researchers can use the procedures of popular, accessible software packages to study an increasingly important set of measurement models.     

Recall and recognition of self-performed acts

Summary In Experiment 1, recall and recognition of 80 action phrases were compared under two encoding conditions: verbal and motor (performing the denoted acts). Memory performance was better under motor encoding than under verbal encoding, and more so in recognition than in recall. We assume that this finding is due to the item-specific effect of a specific motor component in the memory trace after enacting. In Experiments 2 and 3 we further investigated whether false-alarm rates are dependent on the motoric similarity of distractor items. The rate of false alarms was lower under motor encoding than under verbal encoding, but the motoric similarity of distractor items to list items did not influence the false alarms. The results were interpreted as support for the assumption that motor encoding enhances item-specific information in relation to verbal encoding, but that during verbal recognition the motoric quality of the depicted movement is not processed.     

Toward an empirically based parameter selection for time-sampling observation systems

The measurement error of time-sampling observation systems, used to estimate the frequencyof behavioral events, was analyzed by means of a five-factor design, computer simulation experiment. The first three factors represented response parameters: the relative frequency and duration of the behavior and the pattern of response distribution. For each combination of frequency, pattern, and duration, five simulated behavior events were generated within a simulated observation period of 900 sec. A total of 21 different time-sampling systems was employed. As a fourth factor three different observe and record lengths were included (6, 12, and 60 sec). In addition, there were seven different ratios of “observe” to “record” interval length (5∶1, 3∶1, 2∶1, 1∶1, 1∶2, 1∶3, and 1∶5) representing the fifth factor. Thus, 21 time-sampling systems scanned a total of 120 different behavior simulations from 24 types of behavior parameter combinations. The data were analyzed by means of a five-factor (2 × 3 × 4 × 3 × 7) analysis of variance with repeated measures on two factors. The study demonstrated that time sampling leads to high average measurement errors, which are determined by complex interrelationships among a variety of variables. Choosing a time-sampling system arbitrarily may lead to highly erroneous data. It was also shown, however, that time-sampling systems have the potential to yield very accurate results. An empirical selection procedure for time-sampling intervals is proposed to minimize measurement error. Exemplary tables are presented from which time-sampling parameters can be chosen given that the rate, duration, and pattern of occurrence of a behavior to be observed are known.