Lower bounds for the reliability of the total score on a test composed of non-homogeneous items: II: A search procedure to locate the greatest lower bound

Finding the greatest lower bound for the reliability of the total score on a test comprisingn non-homogenous items with dispersion matrix Σ _x is equivalent to maximizing the trace of a diagonal matrix Σ _E with elements θ _I , subject to Σ _E and Σ _T =Σ _x − Σ _E being non-negative definite. The casesn=2 andn=3 are solved explicity. A computer search in the space of the θ _i is developed for the general case. When Guttman's λ₄ (maximum split-half coefficient alpha) is not the g.l.b., the maximizing set of θ _i makes the rank of Σ _T less thann − 1. Numerical examples of various bounds are given. Present affiliation of the first author: St. Hild's College of Education, Durham City, England.     

A dialogue on Zeno's paradox of Achilles and the tortoise

The five participants in this dialogue critically discuss Zeno of Elea's paradox of Achilles and the tortoise. They consider a number of solutions to and restatements of the paradox, together with their philosophical implications. Among the issues investigated include the appearance-reality distinction, Aristotle's distinction between actual and potential infinity, the concept of a continuum, Cantor's continuum hypothesis and theory of transfinite ordinals, and, as a solution to Zeno's puzzle, the distinction between infinite and indeterminate or inexhaustible divisibility.     

A six-month follow-up of adolescents' sexual risk-taking,HIV/AIDS knowledge,and attitudes to condoms

A follow-up study was conducted to investigate change in sexual behaviour, knowledge about HIV/AIDS transmission, and attitudes to condoms over a 6-month period in a sample of late-adolescent students. The study also obtained subjective reports of HIV/AIDS-relevant change. Overall there was a decrease in sexual risk-taking behaviour with casual partners but no change occurred in sexual behaviour with regular partners, knowledge about HIV/AIDS, attitude towards condoms, or intention to use a condom on next sexual encounter. Examination of individual data revealed that, for some adolescents where behavioural change had occurred, this was in the direction of less safe sex. There were few self-reports of change in sexual behaviour, intention to take precautions against HIV/AIDS, or concern about HIV/AIDS over the preceding 6 months. Subjective reports of behaviour change did not correspond with reports of actual behaviour. Low rates of behaviour change are attributed to the failure of adolescents to personalize the threat of AIDS and to their trust in the safety of sex with a regular partner as well as to the lack of relevance of HIV/AIDS education campaigns to this group.     

Instructive feedback: A comparison of simultaneous and alternating presentation of non-target stimuli

Instructive feedback involves presenting extra, non-target stimuli in the consequent events for children's responses. Two methods of presenting instructive feedback during direct instruction were compared. These methods involved presenting two extra stimuli on all trials, and presenting the two extra stimuli separately on alternating trials. Preschool students were taught coin combinations using a constant time delay procedure with instructive feedback stimuli added to both praise and correction statements. An adapted alternating treatments design was used to evaluate the two methods of presenting instructive feedback. The students were assessed to determine the extent to which instructive feedback stimuli were learned. The results indicate that students learned some of the instructive feedback stimuli and no consistent differences in the effectiveness of the two presentation methods were noted. Further, relationships between the two instructive feedback stimuli appeared to be established. Implications for instruction and future research are discussed.     

AIDS PREVENTION: IMPROVING NURSES' COMPLIANCE WITH GLOVE WEARING THROUGH PERFORMANCE FEEDBACK

A performance feedback procedure was used to increase glove wearing by nurses in a hospital emergency room in situations in which contact with body fluids was highly likely. Infection-control nurses provided biweekly performance feedback to staff nurses on an individual private basis to inform them of the percentage of contact opportunities in which they wore gloves. Observations made prior to (baseline) and during feedback in a multiple baseline design across 4 subjects indicated that substantial increases in glove wearing in target situations occurred after implementation of the feedback program and that increases occurred across most of the specific situations in which glove wearing was advised. Percentage increases in glove wearing ranged from 22% to 49% across subjects. The results are discussed in terms of prevention of acquired immune deficiency syndrome (AIDS) by use of universal precautions.     

A resolution to the interpretive dilemmas created by the Minnesota Multiphasic Personality Inventory 2 (MMPI-2)? A reply to Ben-Porath and Graham

In my original article (Strassberg, 1991) I described (1)some of the changes introduced by the MMPI-2, (2) possible interpretive dilemmas created by these changes, and (3) strategies for dealing with these dilemmas. In their reply to my paper, Ben-Porath and Graham (preceding paper) suggest that the differences between the MMPI-2 and the MMPI (1) are to be expected, (2) are less important than I imply, and (3) when they do occur, will almost always reveal the superiority of the MMPI-2. In this reply to Ben-Porath and Graham, I explain why, despite their reassurances, I continue to contend that interpretive dilemmas can exist when using the MMPI-2, but these should not deter us from using this instrument.     

Interpretive dilemmas created by the minnesota multiphasic personality inventory 2 (MMPI-2)

While the new MMPI-2 has the potential to provide more and better clinically relevant information than its predecessor, its introduction also creates several important problems for clinicians and researchers. In particular, the new norms and the use of uniform (rather than linear) T-scores result in the same raw scores on the two tests yielding clinical profiles that can be quite different, both qualitatively and quantitatively. These differences can result in difficulty in MMPI-2 profile interpretation when the user is relying on MMPI interpretive strategies. This paper addresses these concerns and offers some temporary remedial strategies.     

Police communication programmes aimed at burglary victims: A review of studies and an experimental evaluation

The effects and side-effects of a victim assistance project aimed at victims of burglary are experimentally evaluated. Key features of the programme included the provision of burglary prevention information by police officers during a personal interaction with the victim through a positive and limitative communication strategy. Results suggest that important programme goals (for example, stronger satisfaction with police performance, a more internal risk orientation concerning victimization, stronger preventive intentions) were met. One of the positive effects for which experimental support was found was an improvement in police-victim relations. As regards side-effects the programme led neither to response generalization, nor to increased fear of crime outside the home. However, the side-effects of increased fear in the home did occur in female victims and victims with an external risk-orientation. The implications for future victim assistance projects in this domain are finally discussed.