Stability of magnitude production scales for oral and nonoral vibrotactile mechanoreceptive systems

The stability of oral and nonoral vibrotactile magnitude scales produced by the method of magnitude production was investigated for 11 adult subjects. Each subject was tested over four sessions separated by 1-wk. intervals. Data analyses included correlations across trials of power function slopes as well as individual adjustments of intensity. Analysis showed a lack of stability over time for the slope functions obtained on the thenar eminence but moderate stability for the functions obtained on the tongue. Individual adjustments on intensity showed consistently high correlations across trials and structures. It was concluded that the subjects' responses were guided by the imposed experimental variables and that each individual's scaling was not necessarily reflected by the correlations based on power function slopes established over the four trials.     

Psychophysical parameters of the perception of orally-retained liquid bulk

Bulk of liquid held in the mouth may be judged on its subjective volume. Over the range I ml-31 ml, scaling by the constant method and by ratio estimation yielded a Weber fraction which was not constant and decreased with stimulus magnitudes and a psychophysical power function with an exponent of 0.96. A “negative threshold” effect is reported.     

Evaluation of visual display surfaces by real users early in the design stage

Groups of non-computer scientists were tested to evaluate the potential of an as yet non-existent interactive terminal with a screen diagonal of one meter. A simulated large image terminal provided limited realistic interactions using software developed to give close proximity to the predicted visual effect. Subjective responses from 101 subjects were elicited from a questionnaire designed to evaluate specific aspects of the “terminal” in use. From this data, two types of screen (lenticular and plain) and two types of interaction devices (touch and remote pointer) were analyzed experimentally using a two-way factorial design. Potential end-users provided positive feedback concerning future use of the Large Image Terminal. Building a realistic mock-up revealed screen contaminations which would not have been discovered until a much later stage. Although statistical analysis of screen evaluations was equivocal, the questionnaire was sufficiently penetrating to separate the positive and negative features. This methodology was invaluable in guiding the design process. Copies of the questionnaire may be obtained from the authors at the Heriot-Watt address.     

Preemployment screening procedures: How human resource managers perceive them

A survey of Human Resource practitioners' perceptions of pre-employment screening procedures was conducted. The results indicated differences between tests in terms of perceived accuracy and offensiveness, as well as other attributes. Regression analyses suggested that beliefs about validity, the number of other companies using these procedures, perceived offensiveness of the test, and ease in passing the test were important factors in the willingness to use a particular test. Conversely, perceptions regarding the discriminatory impact of the test and the cost of using the test generally were not related to willingness to use the test. Limitations of this study, which was primarily exploratory, are noted.     

Racial Identity Development Among Gifted Black Students: Counseling Issues and Concerns

A review of the literature suggests that a paucity of information exists regarding how culture-specific issues such as being both Black and gifted influence the psychological needs and personality development of gifted Black students. Stellar attempts, however, are currently underway to develop theories and perspectives of racial identity development among Black students. These theories and perspectives are discussed in an attempt to understand and address the psychological and social needs of gifted Black students.