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The current study integrates descriptive (though primarily social-psychological) statements about youth suicide into a coherent, empirically supported taxonomy. Drawing from relevant literature, a set of 107 items characterizing these contributions about youth suicide was created. Seventy-two participants sorted these statements according to their "face-value" by following two separate procedures. Analyses of these two data sets using multi-dimensional scaling resulted in a common "map" depicting inter-item (dis)similarities. Non-arbitrary rotation of this map revealed three bipolar and orthogonal dimensions labelled as under- and overengagement, rejection-turmoil, and self- to death-identification. It is suggested this dimensional analysis could provide aviable frame for examining and interpreting descriptions about suicide risk and may serve to extend theoretical accounts.

Attachment Q-Sort (AQS) is a tool for quantifying observations about toddler/caregiver relationships. Previous studies have applied factor analysis to the full 90 AQS item set to explore the structure underlying them. Here we explore that structure by applying multidimensional scaling (MDS) to judgements of inter-item similarity. AQS items are arranged in the MDS solution along three easily interpretable axes: a model that is compatible with but more parsimonious than factor analysis solutions. This geometrical approach suggests ways to modify the AQS--primarily a research tool--to make it more practical for clinical applications. Sets of AQS data are represented and interpreted in the three-dimensional model as vectors. Summaries at a finer-grained level are obtained by finding points in the model where variability across datasets is greatest. We report re-analyses of archival (published) data, and also data collected with streamlined procedures more suitable in the field. Although not reported here, collection and analysis can both be performed online via a website. The general methodology is not restricted to the current application of toddler attachment.

Applied multidimensional scaling to similarity data to produce a model of Attachment Q-Set (AQS) items as points in a 3-dimensional space. Represented criterion sorts, individual Q-sorts, and empirical correlates as vectors, interpreting each according to the vector's contributions from the three global dimensions. Tested the model's validity and compared the system with three sets of published AQS criterion scales, examining connections among the latter within the model's framework. (Author/KB)

"Points-of-View" analysis has been promoted as an appropriate analysis for similarity data collected with the Method of Sorting. It can be regarded as an extension of Cultural Consensus Analysis (CCA). The latter assumes that subjects all base their responses on a single shared 'model' of the items to be sorted (while varying in the level of reliability with which they consult that model). Conversely, the titular "points-of-view" are multiple models, sampled singularly by some subjects' responses, while other subjects combine the models in various proportions. The analysis appears to be comparatively insensitive to the artefacts to which sorting data are prone, which affect how easily they can be interpreted with (for instance) multidimensional scaling (MDS). Here we apply the Points-of-View approach to two sets of data from the colour domain, a sensory modality well-suited for the sorting procedure. One study extracted three viewpoints - i.e., factors, prototypal ways of organising the stimuli - with one viewpoint specific to colour-vision-deficient observers, capturing independently-measured differences among the subjects. In the second study, two viewpoints proved to be appropriate: one arranged the items by two dimensions, lightness/saturation as well as hue, while the second was essentially a one-dimensional hue-based arrangement. This distinction could not be recovered from the raw data by applying MDS with the weighted-Euclidean model of individual difference. We discuss some demographic factors which might dispose subjects to attend to hue only or saturation/lightness as well. [ABSTRACT FROM AUTHOR]

"Cultural consensus analysis" (CCA) of similarity data involves analyzing the matrix of inter-subject correlations with Factor Analysis. If the pattern of correlations can be explained by a single dominant factor, one can assume that the subjects grouped the items according to a shared mental model - a cultural consensus - and their responses can safely be merged in subsequent stages of analysis. In the negative case where no consensus exists and the pattern of correlations contains more than one factor, we argue that a logical extension of CCA is the Points-of-View approach of Tucker and Messick. Each "point of view" (PoV) is an idealized or prototypal mode of organizing the items, obtained by rotating the factors to simple structure. The distinct organization present in each PoV can be made explicit by considering it as a matrix of item proximities, suitable for clustering or multidimensional scaling. To account for each subject's data, these idealized modes are combined in proportions given by the subject's factor loadings. Following a canonical application of CCA, subjects sorted a list of animal names. The Points-of-View model accommodated the variations among subjects, while clarifying the distinct mental models forming the extremes of their variation. [ABSTRACT FROM AUTHOR]

Abstract: We examined colour perception among a group of women heterozygous for colour vision deficiency. Judgements of colour dissimilarity were collected by presenting colour stimuli in groups of three for odd-one-out decisions. The judgements were summarised as one consensus colour space for the heterozygotes and another for age-matched controls. Individual differences MDS was also applied, resulting in a single colour space which can be adjusted to fit each subject’s responses individually by compressing it along its axes. Heterozygous women showed a trend towards colour-space compression in a red–green dimension, or reduced salience of that dimension compared to controls, though less extreme than found in overt colour deficiency. [Copyright &y& Elsevier]

The structure of color perception can be examined by collecting judgments about color dissimilarities. In the procedure used here, stimuli are presented three at a time on a computer monitor and the spontaneous grouping of most-similar stimuli into gestalts provides the dissimilarity comparisons. Analysis with multidimensional scaling allows such judgments to be pooled from a number of observers without obscuring the variations among them. The anomalous perceptions of color-deficient observers produce comparisons that are represented well by a geometric model of compressed individual color spaces, with different forms of deficiency distinguished by different directions of compression. The geometrical model is also capable of accommodating the normal spectrum of variation, so that there is greater variation in compression parameters between tests on normal subjects than in those between repeated tests on individual subjects. The method is sufficiently sensitive and the variations sufficiently large that they are not obscured by the use of a range of monitors, even under somewhat loosely controlled conditions. [ABSTRACT FROM AUTHOR]

Recent studies have shown that the perception of facial expressions of emotion fits the criteria of categorical perception (CP). The present paper tests whether a pattern of categories emerges when facial expressions are examined within the framework of multidimensional scaling. Blends of five "pure" expressions (Angry, Sad, Surprised, Happy, Neutral) were created using computerised "morphing", providing the stimuli for four experiments. Instead of attempting to identify these stimuli, subjects described the proximities between them, using two quite different forms of data: similarity comparisons, and sorting partitions. Multidimensional scaling techniques were applied to integrate the resulting ordinal-level data into models which represent the interstimulus similarities at ratio level. All four experiments yielded strong evidence that the expressions were perceived in distinct categories. Adjacent pairs in the models were not spaced at equal intervals, but were clustered together as if drawn towards a "perceptual magnet" within each category. We argue that spatial representations are compatible with CP effects, and indeed are a useful tool for investigating them. [ABSTRACT FROM AUTHOR]

have proposed that teachers’ emotional skills, as required in the classroom, can be organized into a five-dimensional model. Further research is necessary to validate this model and evaluate the importance of each dimension of teacher emotion competence for educational practice. Using a statistical method for mapping psychological constructs, teachers’ emotional practices were transformed into a ‘map’ with three spatial dimensions, which was supported by comparative validity checks. The nature of emotional practice was further investigated by administering a Q-Sort of emotional practice items to 100 teachers. Ten highly applicable clusters of emotional behavior across six profile patterns with teachers were identified. Authors’ model and the applicability of emotions were generally supported. [Copyright &y& Elsevier]