Reliability, homogeneity and the construct validity of Cattell's 16PF

This paper reviews criticisms of the psychometric properties of Cattell's Sixteen Personality Factor Questionnaire and examines Cattell's claims that 16PF scale reliabilities and factor validities are seriously underestimated by conventional internal consistency approaches to reliability estimation.On large samples of British adults and undergraduates no evidence was found to support the claim that the 16PF is deliberately heterogeneous in item content. No presence of suppressor effects or balancing of specifics were found in the 16PF scales, most of which were reasonably homogenous by conventional standards. Conventional internal-consistency reliability estimates in fact give very similar results to alternate form reliability coefficients and Cattell's factorial validities. 16PF scales which were particularly poor in terms of scale consistency were L, M and N with C, O and Q4 emerging as measures of essentially the same trait of anxiety.     

Control of CRT intensity via Apple II software

An inexpensive, easy-to-build device for the Apple II microprocessor is described. The modification permits software control of four levels of relative screen intensity (contrast) settings for any video monitor. The relationship of the technology to choice reaction time and perception research is briefly indicated. Principles governing operation of the modification are also discussed. Finally, a set of step-by-step instructions for building the device is provided.     

Rater information acquisition processes: Tracing the effects of prior knowledge, performance level, search constraint, and memory demand

Research on performance ratings has tended to neglect factors affecting raters' acquisition of ratee performance information. The present research examined the dynamic effects of this rater information acquisition process. Study 1 examined the effects of prior ratee knowledge (familiarity) and ratee performance level on subsequent acquisition of ratee performance information under varying levels of constraint. After exposure to prior ratee information, raters acquired additional information concerning a set of ratees using a computer controlled information board procedure. The results indicated significant effects on the amount of search for prior knowledge, search constraint, and the interaction between prior knowledge and performance level. Study 2 extended the research by including a memory component (time delay) between the exposure to prior information and subsequent search. Results were congruent with Study 1. They indicated significant main effects on the amount of search for prior knowledge, ratee performance level, search constraint, and on the interaction between prior knowledge and performance level. In addition, the results indicated a significant interaction between memory demand and prior knowledge. Implications of these results, limitations, and extensions of this research approach are discussed.     

Microsecond resolution timing with Sun workstations

A high-resolution clock is often indispensable for the accurate measurement of millisecond or microsecond resolution intervals, and it is impossible to measure the probability distribution of short intervals without one. This paper describes a microsecond clock for Sun 3 and 4 workstations that we designed, built, and have made publicly available. It also explains how to measure intervals shorter than a computer’s clock resolution, and derives confidence intervals for such measurements.     

Real-time clocks for microcomputers in behavioral research

Real-time clock strategies are described for microcomputers in behavioral research. Software-oriented and hardware-oriented counters are described in both free-running and strobed modes. An example of a clock using the Intel 8253 is given, along with driving software in 8080 assembly code and hardware for the S-100 bus.     

Parental Visitation of the Institutionalized Retarded

An inverse relationship was found between the number of parental visits an institutionalized retarded child received and the distance of the parental home from the institution. When the natural parents were living together, the retarded child was shown to receive more visits than when the child's parents were separated or one parent was deceased. Single mothers were found to be living significantly closer to the facility than single fathers. Single fathers appeared to put more effort into visiting, since they visited just as often as the mothers, but had to travel further distances than the mothers to do so. Visitation frequency followed a curvilinear pattern, decreasing uniformly from 20–60 miles (from 0–20 miles visitation frequency is uniform), and then leveling off.     

Temporal properties of responding during stimuli that precede response-independent food

Pigeons' keypecks were reinforced with grain on the average of once per minute by schedules that maintained low response rates and by schedules that maintained high response rates. During these schedules, a fixed-duration conditioned stimulus (CS) ranging from 7.5 to 120 sec in duration across conditions terminated with response-independent food. Response rates during the CS were inversely related to CS duration. The rates and the temporal patterns of responding during the shortest CS were similar whether the ongoing schedule maintained high response rates or low response rates. As CS duration increased, the rate and pattern of responding during the CS converged on the rate and pattern of responding maintained by the baseline schedule. These data indicate that changes in responding during stimuli that signal response-independent reinforcement are not homogeneous throughout the CS; that response measures, such as “suppression ratios”, which presume homogeneity may mislead us; and that conditioned suppression and conditioned enhancement may be better talked about in terms of species-specific approach and avoidance than in terms of emotional states.     

When timing the mind one should also mind the timing: biases in the measurement of voluntary actions

Trevena and Miller (2002, this issue) provide further evidence that readiness potentials occur in the brain prior to the time that participants claim to have initiated a voluntary movement, a contention originally forwarded by Libet, Gleason, Wright, and Pearl (1983). In their examination of this issue, though, aspects of their data lead them to question whether their measurement of the initiation of a voluntary movement was accurate. The current article addresses this concern by providing a direct analysis of biases in this task. This was done by asking participants to make subjective timing decisions regarding a stimulus that could be measured objectively. Our findings suggest that their timing task was indeed biased such that participants' tend to report events as happening approximately 70 ms later than they actually happened. Implications for the original Libet et al. claims are discussed.     

Transforming mental health care for children and their families

In April 2002, the President's New Freedom Commission on Mental Health was created by executive order to study the mental health care delivery system in our nation and to make recommendations for improvements so that individuals with serious mental disorders can live, work, learn, and fully participate in their homes and communities. In its report, "Achieving the Promise: Transforming Mental Health Care in America," the commission provided strategies to address critical infrastructure, practice, and research issues. This article focuses on the work of the commission's Subcommittee on Children and Families, describing its vision for mental health service delivery for children and providing suggestions for strengthening community-based care for youths with or at risk of behavioral health disorders. Training, research, practice, and policy implications for psychologists are discussed.