Sources of Bias in Health Commission and Tobacco Industry Surveys in Australia

Recently, the attitudes held by Australians towards tobacco company advertising and sponsorship have become the focus of much public discussion and the concern of psychological researchers and opinion pollsters. Community attitude surveys have been commissioned by both supporters and opponents of the tobacco industry. Paradoxically, the data obtained from these surveys allow each protagonist to state that the majority of Australians agree with their viewpoint The present authors have identified several sources of possible bias in two surveys as causes of contradictory research findings. A questionnaire was designed which attempted to reduce the sources of bias and which incorporated other methodological refinements. The data obtained highlight how the form of the questions may substantially influence responses in attitude surveys.     

TEACHING SAFETY SKILLS TO HIGH SCHOOL STUDENTS WITH MODERATE DISABILITIES

Teaching students with disabilities to respond appropriately to potentially dangerous situations is a useful skill that has received little research attention. This investigation taught 3 students with moderate mental retardation to remove and discard broken materials (plates, glasses) safely from (a) a sink containing dishwater, (b) a countertop, and (c) a floor. A 4th student was instructed on the sink task only. A multicomponent treatment package was used to teach the skills. Simulated materials were used initially and were replaced with broken plates and glasses. A multiple probe design was used to evaluate the effectiveness of the treatment package. The results indicated that the treatment package was effective in teaching the skills. Data were collected 1 week and 1 month following the completion of training, and indicated mixed results. No student was injured during any phase of training. Issues pertinent to teaching safety skills to students with moderate disabilities are discussed.     

Perceptual restoration of a "missing" speech sound: auditory induction or illusion?

This study investigated whether the apparent completeness of the acoustic speech signal during phonemic restoration derives from a process of auditory induction (Warren, 1984) or segregation, or whether it is an auditory illusion that accompanies the completion of an abstract phonological representation. Specifically, five experiments tested the prediction of the auditory induction (segregation) hypothesis that active perceptual restoration of an [s] noise that has been replaced with an extraneous noise would use up a portion of that noise's high-frequency energy and consequently change the perceived pitch (timbre, brightness) of the extraneous noise. Listeners were required to compare the pitch of a target noise, which replaced a fricative noise in a sentence, with that of a probe noise preceding or following the speech. In the first two experiments, a significant tendency was found in favor of the auditory induction hypothesis, although the effect was small and may have been caused by variations in acoustic context. In the following three experiments, a larger variety of stimuli were used and context was controlled more carefully; this yielded negative results. Phoneme identification responses collected in the same experiments, as well as informal observations about the quality of the restored phoneme, suggested that restoration of a fricative phone distinct from the extraneous noise did not occur; rather, the spectrum of the extraneous noise itself influenced phoneme identification. These results suggest that the apparent auditory restoration which accompanies phonemic restoration is illusory, and that the schema-guided process of phoneme restoration does not interact with auditory processing.     

Discriminability between alternatives in a switching-key concurrent schedule

Six pigeons were trained to discriminate between two intensities of white light in a symbolic matching-to-sample procedure. These stimuli were then used to signal which schedule was available on the main key in a switching-key concurrent schedule. The concurrent schedules led to a symbolic matching-to-sample phase in which the subject identified the concurrent schedule to which it last responded before a reinforcer could be obtained. The concurrent schedules were varied across conditions. Discriminability, measured during the symbolic matching-to-sample performance, was high throughout and did not differ across the two procedures. Performance in the concurrent schedules was like that typically obtained using these schedules. Delays were then arranged between completion of the concurrent schedules and presentations of the symbolic matching-to-sample phase. A series of conditions with an intervening delay of 10 s showed that both concurrent-schedule performance and symbolic matching-to-sample performance were affected by the delay in a similar way; that is, choice responding was closer to indifference.     

Structural alterations of an ambiguous musical figure: the scale illusion revisited.

The scale illusion (Deutsch, 1975) shows the importance of frequency range in the perceptual organization of a sequence of notes. This paper includes three experiments on the scale illusion. Experiments 1 and 2 demonstrated that if the structure of the pattern of notes used in the original scale illusion study is altered slightly, by adding or subtracting a pair of notes from the ends of the sequence, there is a significant decrease in the rate of frequency-based responses, suggesting a weaker illusion. Experiment 3 investigated two features of the note patterns that may have led to this change. Specifically, it asked whether the decrease in the strength of the illusion is due to (1) the nature of the notes at the extremes of the frequency range and/or (2) the nature of the notes at the crossing point of the two scales. While both sources were found to affect the strength of the scale illusion, the former had a greater influence.     

THE INFLUENCE OF ASSESSEE PERFORMANCE VARIATION ON ASSESSORS'JUDGMENTS

Assessors evaluated assessees'performances in one of three performance conditions in an assessment center simulation: a consistent performance condition, a within-assessee performance variation condition, or a between-assessee performance variation condition. Contrast effects influenced ratings of assessees when there was variation in performance within assessees. For each assessee, the low target performance was rated lower when the assessee's prior performance had been dissimilar (high) than when the assessee's prior performance had been similar (low). Contrast effects also infiuenced assessors'ratings of the target assessee when there was variation in performance among assessees. The low performing target assessee was rated significantly lower when he was evaluated with two high performers than when he was evaluated with two low performers. In addition, ratings obtained when there was performance variation among assessees were more accurate than those obtained when there was no performance variation, suggesting that under some circumstances contrast effects may not lead to inferior judgments.     

A generalized visual latency explanation of the Pulfrich phenomenon.

The classical visual latency explanation of the Pulfrich phenomenon is generalized to allow for the possibility that the visual system uses velocity information from motion detectors to compensate for spatial lag due to time lag, in identifying the instantaneous position of a moving object. The results of the reported experiment verify one consequence of the generalized version: the elliptical apparent path is skewed away from the filtered eye. The results suggest also that the extrapolation factor increases with visual latency and that there is a different extrapolation factor for each eye when the eyes are illuminated unequally.     

Self-perceived information needs and concerns of elderly persons.

The research was intended to identify the dimensions underlying self-perceived information needs and concerns of an elderly population. The spontaneously mentioned needs and concerns expressed in 271 letters from a sample of the population were extracted and a multidimensional scaling procedure was used to represent the 58 most frequently mentioned items in configurations of varying dimensionality. To interpret the multidimensional spaces, another sample of 176 elderly subjects was asked to rate the 58 concerns on eight properties. These ratings were then regressed onto the multidimensional configurations. The results indicate that the most frequently mentioned information needs and concerns of elderly persons can be parsimoniously understood in terms of three underlying dimensions: (1) Improving the Quality of Life vs Securing the Necessities of Life, (2) Health-related vs Not Health-related, and (3) Individual vs Societal Responsibility.