Effect of line orientation on various information-processing tasks

The effects of interstimulus and stimulus-specific factors on central (vs. peripheral) oblique effects were examined using classification, focusing, discrimination, and sequential same-different tasks. Classification results showed that grouping the vertical with the horizontal line and the two diagonal lines with each other facilitated performance. Discrimination results revealed that the two diagonal lines were more confusable with each other than were the members of any other stimulus pair. Focusing results indicated that the vertical and horizontal lines served as better focusing stimuli. A set of sequential same-different tasks, each using only two alternative stimuli, allowed for the examination of stimulus-specific factors in focusing; the effects of similarity relations between all stimuli in the total set were greatly reduced by the constrained context. The two diagonal lines were the most difficult to compare and proved to be the worst foci in these tasks as well. In conclusion, there are two factors operating in the central oblique effect: greater confusability between the two diagonal lines and more favorable stimulus-specific properties of vertical and horizontal lines.     

Effects of semantic and nonsemantic cued orienting tasks on associative clustering in free recall

Memory & Cognition - During presentation of a randomized list of nonadjacent associative pairs, Ss heard a cue after each word designating the task to be performed. All Ss performed two tasks....     

Stimules configuration in selective attention tasks

The possibility that perceptual configuration of stimulus elements impairs the ability to attend selectively to individual elements was tested with two-element stimuli, constructed by placing two curved lines in close proximity. Ss rapidly classified series of these stimuli which could differ on both elements or on only one with the second held constant. It was hypothesized that if the two elements formed a configuration, then Ss should have difficulty attending selectively to the element relevant for classification while filtering information from the other element. This result was obtained in one experiment with both stimulus elements oriented vertically, and it is concluded that these stimuli were perceived as unanalyzed, nominally related shapes. In another experiment, with one stimulus element oriented horizontally, selective attention to the relevant element was possible.     

Feature analyzers for the phonetic dimensionstop vs. continuant

Perception of sounds along the phonetic dimensionstop vs. continuant was studied by means of a selective adaptation procedure. Subjects first identified a series of synthetic consonant-vowel syllables whose formant transitions varied in duration, slope, and amplitude characteristics. They were perceived as either [ba] or [wa]. After the initial identification test, an adapting stimulus was presented repeatedly, and then the subjects again identified the original test series. Adapting with a stop (either [ba] or [da]) led to a decrease in the number of test stimuli identified as [ba], whereas adapting with the continuant sound [wa] led to an increase in the number of [ba] identification responses. Removing the vowel portion of an adapting stimulus greatly reduced the identification shift only when the resulting stimulus was no longer perceived as speech-like. A reduction in the number of [ba] identifications occurred even when a nonspeech “stop” (the sound of a plucked string) was used as the adapting stimulus, suggesting that phonetic processing is not a necessary condition for an adaptation effect.     

On the partitioning of squared Euclidean distance and its applications in cluster analysis

The partitioning of squared Eucliean distance between two vectors in M-dimensional space into the sum of squared lengths of vectors in mutually orthogonal subspaces is discussed and applications given to specific cluster analysis problems. Examples of how the partitioning idea can be used to help describe and interpret derived clusters, derive similarity measures for use in cluster analysis, and to design Monte Carlo studies with carefully specified types and magnitudes of differences between the underlying population mean vectors are presented. Most of the example applications presented in this paper involve the clustering of longitudinal data, but their use in cluster analysis need not be limited to this arena.     

Development and psychometric properties of the Children's Assertive Behavior Scale

The purpose of this paper is to present the psychometric properties and individual items comprising the Children's Assertive Behavior Scale (CABS). The CABS is a behaviorally designed self-report instrument for children which measures general and specific social skills and covers many socially relevant situations which are problematic for children. Acceptable psychometric properties of the 27-item test were obtained in several independent investigations across both geographical regions and grade levels. The CABS showed significant concurrent validity with peer, parent, and teacher measures of social competency. The CABS also discriminated trained versus untrained children participating in social skills versus a placebo discussion group. The instrument is presented, along with recommendations for future applications and research.Both authors share equal responsibility for the development and evaluation of the Children's Assertive Behavior Scale.     

The effects on speeded classification of implicit and explicit instructions regarding redundant dimensions

Two experiments were run in which speed of sorting decks of stimulus cards was measured. Stimuli were constructed from two dichotomous dimensions, used either alone or perfectly correlated. The lack of evidence for a selective serial processing (SSP) strategy (in which S sorts by his most preferred dimension whenever the dimensions are correlated) in a similar study by Garner and Felfoldy (1970) was thought to be due to Ss’ failure to notice that the dimensions were correlated, and thus that SSP would be effective. Ss in the present experiment therefore received either implicit instructions concerning the existence of the correlated deck (by seeing only decks in which there were just two different stimuli), or explicit instructions that on some trials the two dimensions would be correlated and S could sort by any means he preferred. When dimensions of size of circle and angle of diameter were of unequal discriminability, implicit instructions produced partial use of the SSP strategy, while explicit instructions produced nearly total use of SSP by all Ss. When the Munsell dimensions of value and chroma were varied in two separate color chips and were equally discriminable on the average, evidence for a small amount of SSP was found in both the implicit and explicit conditions. With neither pair of dimensions did implicit or explicit instructions regarding the correlated task produce integration of information.