Estimating latent correlations between repeated testings

A model for longitudinal latent structure analysis is proposed. We assume that test scores for a given mental or attitudinal test are observed for the same individuals at two different points in time. The purpose of the analysis is to fit a model that combines the values of the latent variable at the two time points in a two-dimensional latent density. The correlation coefficient between the two values of the latent variable can then be estimated. The theory and methods are illustrated by a Danish dataset concerning psychic vulnerability.     

The reflecting team: dialogue and meta-dialogue in clinical work

A "stuck" system, that is, a family with a problem, needs new ideas in order to broaden its perspectives and its contextual premises. In this approach, a team behind a one-way screen watches and listens to an interviewer's conversation with the family members. The interviewer, with the permission of the family, then asks the team members about their perceptions of what went on in the interview. The family and the interviewer watch and listen to the team discussion. The interviewer then asks the family to comment on what they have heard. This may happen once or several times during an interview. In this article, we will first describe the way we interview the family because the interview is the source from which the reflections flow. We will then describe and exemplify the reflecting team's manner of working and give some guidelines because the process of observation has a tendency to magnify every utterance. Two case examples will be used as illustrations.     

Cooperativity, priming, and 3-D surface detection from optic flow

Three experiments were conducted to determine whether the mechanisms responsible for the detection of three-dimensional (3-D) surfaces from optic flow operate in a cooperative manner. The first experiment was conducted to determine whether a hysteresis effect occurs for 3-D surface detection from optic flow. The results of the first experiment demonstrated a hysteresis effect with lower thresholds occurring for decreasing texture density than for increasing texture density. The second experiment used a priming methodology to determine whether this form of cooperativity was based on preactivation of shear detectors or preactivation of 2-D motion detectors. The results suggest that only shear detectors were primed. The third experiment utilized a similar methodology to determine whether a surface representation would produce a priming effect. We found no evidence that the priming effect found in the second experiment was the result of preactivation of a generic representation of the test stimuli. The results of the experiments, considered together, suggest priming of the mechanisms responsible for recovering shear.     

Clinical Geropsychology: Implications for Practice in Medical Settings

Older adults are a rapidly growing segment of the population, who have high rates of chronic illness and who utilize health care resources heavily. Psychologists must become better prepared to work with older patients in geriatric settings, including geriatric assessment units, memory disorders clinics, and nursing homes. In addition, all psychologists will increasingly encounter older patients in environments such as primary care clinics, rehabilitation settings, and disease management programs focusing on problems that are prevalent in older patients (e.g., cancer, diabetes). Suggestions are offered for adaptation of usual clinical practice to address the special needs of older patients and their families, and recommendations made for advancing and expanding the practice of clinical geropsychology.     

Relationship between binocular disparity and motion parallax in surface detection

The ability to detect surfaces was studied in a multiple-cue condition in which binocular disparity and motion parallax could specify independent depth configurations. On trials on which binocular disparity and motion parallax were presented together, either binocular disparity or motion parallax could indicate a surface in one of two intervals; in the other interval, both sources indicated a volume of random points. Surface detection when the two sources of information were present and compatible was not better than detection in baseline conditions, in which only one source of information was present. When binocular disparity and motion specified incompatible depths, observers’ ability to detect a surface was severely impaired if motion indicated a surface but binocular disparity did not. Performance was not as severely degraded when binocular disparity indicated a surface and motion did not. This dominance of binocular disparity persisted in the presence of foreknowledge about which source of information would be relevant.     

THE SPLIT LEVEL PROBLEM AS RELATED TO THE TASK OF EVALUATING ITEMS IN THE CLINICAL AREA

H olley , J. W. & H ansson , K. The split level problem as related to the task of evaluating items in the clinical area. Scand.J. Psychol ., 1969, 10, 124–128—It is pointed out that correlational values can be distorted in item evaluation when the proportions of persons in the criterion groups are variant. The use of a 'K ratio' is suggested as a possible solution to be applied under restrictive conditions.     

Sufficient statistics and latent trait models

For questionnaires with two answer categories, it has been proven in complete generality that if a minimal sufficient statistic exists for the individual parameter and if it is the same statistic for all values of the item parameters, then the raw score (or the number of correct answers) is the minimal sufficient statistic. It follows that the model must by of the Rasch type with logistic item characteristic curves and equal item-discriminating powers.This paper extends these results to multiple choice questionnaires. It is shown that the minimal sufficient statistic for the individual parameter is a function of the so-called score vector. It is also shown that the so-called equidistant scoring is the only scoring of a questionnaire that allows for a real valued sufficient statistic that is independent of the item parameters, if a certain ordering property for the sufficient statistic holds.     

PROBLEM SOLVING AND THE ABILITY TO FIND REPLACEMENTS

Problem situations of the practical construction type may be regarded as situations characterized by a 'missing part'. The solution of a problem depends on the subject's awareness of what is missing, along with his ability to find a replacement for it. Scores on a test measuring this ability are compared with performance on two practical construction problems. Subjects who are successful on the problems have a higher mean score on the 'replacement test'. Scores on a 'function-naming' test are not found to correlate with performance on the problem.     

COMPARATIVE STUDIES OF SENSORY RELATEDNESS OF ODOURS

Measures of relatedness of odours were obtained by means of two psychophysical methods and one electrophysiological technique. The psychophysical data consisted of similarity judgments and confusion measures. The electrophysiological data were based upon statistical treatment of the responses of single units in the olfactory bulb of the frog. Significant rank correlations were obtained between the results of the three methods. The significance of psychological relatedness data for the study of basic receptor processes is discussed.     

SEX DIFFERENCES ON PROBLEM-SOLVING TASKS

The question of sex differences in problem solving is discussed and some findings reported. Female subjects did as well as males on practical construction problems presented in writing. No sex difference was found on a 'function-naming' test, but female subjects were found to be superior when the task was to list replacements for missing implements.