Missing values at the end of a test typically are the result of test takers running out of time and can as such be understood by studying test takers’ working speed. As testing moves to computer-based assessment, response times become available allowing to simulatenously model speed and ability. Integrating research on response time modeling with research on modeling missing responses, we propose using response times to model missing values due to time limits. We identify similarities between approaches used to account for not-reached items (Rose et al. in ETS Res Rep Ser 2010:i–53, 2010) and the speed-accuracy (SA) model for joint modeling of effective speed and effective ability as proposed by van der Linden (Psychometrika 72(3):287–308, 2007). In a simulation, we show (a) that the SA model can recover parameters in the presence of missing values due to time limits and (b) that the response time model, using item-level timing information rather than a count of not-reached items, results in person parameter estimates that differ from missing data IRT models applied to not-reached items. We propose using the SA model to model the missing data process and to use both, ability and speed, to describe the performance of test takers. We illustrate the application of the model in an empirical analysis.
In three experiments, we investigated how associative word-word priming effects in German depend on different types of syntactic context in which the related words are embedded. The associative relation always concerned a verb as prime and a noun as target. Prime word and target word were embedded in visually presented strings of words that formed either a correct sentence, a scrambled list of words, or a sentence in which the target noun and the preceding definite article disagreed in syntactic gender. In contrast to previous studies (O’Seaghdha, 1989; Simpson, Peterson, Casteel, & Burgess, 1989), associative priming effects were not only obtained in correct sentences but also in scrambled word lists. Associative priming, however, was not obtained when the definite article and the target noun disagreed in syntactic gender. The latter finding suggests that a rather local violation of syntactic coherence reduces or eliminates word-word priming effects. The results are discussed in the context of related work on the effect of gender dis-/agreement between a syntactic context and a target noun. 相似文献
An important recent insight in a number of neurobiological systems is that during learning, individual dually regulated proteins with associative properties function as critical sites of stimulus convergence. During conditioning in Aplysia, the Ca2+ /calmodulin-sensitive adenylyl cyclase (AC) in mechanosensory neurons serves as a molecular site of interaction between Ca2+ and serotonin [5-hydroxytryptamine (5-HT)]-two signals that represent the CS and US in these cells. Conditioning requires that the CS and US be paired within a narrow time window and in the appropriate sequence. AC shows an analogous sequence preference: It is more effectively activated when a pulse of Ca2+ precedes a pulse of 5-HT than when the 5-HT precedes Ca2+. One mechanism that contributes to this sequence preference is that Ca2+/calmodulin binding to AC accelerates the rate of AC activation by receptor-Gs. We have identified two additional properties of AC activation that would cause pairing with Ca2+ preceding 5-HT to be more effective than simultaneous pairing or pairing with the reciprocal sequence: (1) Activation of Aplysia AC by a Ca2+ pulse rose with a delay compared with activation by a 5-HT pulse. (2) A late pulse of Ca2+, which arrived after 5-HT, acted, via calmodulin, to accelerate the decay of AC activation by receptor-Gs. Together, these activation properties of AC may contribute to the CS-US sequence requirement of classical conditioning. 相似文献
Changing the position of a light source illuminating a human face induces an apparent shift of the perceived orientation of that face. The direction of this apparent shift is opposite to the shift of the light source. We demonstrated the illumination-induced apparent orientation shift (IAOS), quantified it in terms of the physical orientation shift needed to compensate for it, and evaluated the results in the context of possible mechanisms underlying orientation judgment. Results indicate that IAOS depends not only on the angle between the two light source positions, but also on the mean orientation of the face. Availability of cues coded in the visual texture of the face did not affect IAOS. The most effective cue was the location of the visible outline of the face. IAOS seems to be due to a shift of this outline when shadowed areas on the face merge with the black background. We conclude that an important mechanism for orientation judgment is based on a comparison of visible parts left and right of the profile line. 相似文献
The present study applied Karolinska Scales of Personality (KSP) to study (i) if patients with benzodiazepine dependence have a characteristic personality profile, (ii) if the personality characteristics in patients with benzodiazepine dependence differ from those of polydrug users and normal controls, (iii) if differences in treatment outcome existed between the groups, and (iv) if the possible difference in treatment outcome was associated with any particular personality characteristic shown by the patients. The personality characteristics of primary benzodiazepine dependent patients (BDZ) and a group of polydrug users (MIX) were studied initially (during the first week in project as an inpatient) and approximately one year after drug discontinuation, and a comparison was made with healthy controls on both test occasions. The results showed that the personality of both groups of patients differed significantly from the Controls in the following characteristics: Detachment, Socialization, Somatic Anxiety, Muscular Tension, Psychic Anxiety, and Psychasthenia. Significant differences existed between the polydrug and benzodiazepine users in Somatic and Psychic Anxiety as well as in Socialization. The MIX group differed significantly from the BDZ group and from the Controls in Suspicion. Results of treatment outcome indicated that the benzodiazepine dependent patients were significantly more successful in quitting their drug use compared to polydrug users. Further, the results demonstrated that patients scoring high in the investigated personality characteristics are those who fail the treatment goal of quitting their drug use, especially the patients with a high level of anxiety and detachment. 相似文献
Ohne ZusammenfassungDer hier behandelte Wahrheitsbegriff ist die philosophische Grundlage der 3- und 6-wertigen Logik, die ich in [1], [2] und anderen Arbeiten entwickelt habe. Die Leser, die diese Arbeiten kennen, bitte ich um Nachsicht für einige Wiederholungen, die anderen bitte ich um Nachsicht dafür, daß ich nicht mehr wiederhole. 相似文献