A Winchester hard-disk integrated computer-assisted instructional laboratory: Hardware and data management considerations

The hardware configuration at the University of Kentucky is discussed with emphasis on a Winchester technology hard disk as the integrating feature. Advantages and disadvantages of this configuration are discussed in light of the issues of software transportability, ease of use for students, and system maintenance. The Winchester disk is compared to floppy drives as a means of program and data storage. The importance of proper, clear, and organized documentation is stressed. The conclusion is that each system can complement the other in a functional computer learning laboratory.     

Effects of reinforcement magnitude on interval and ratio schedules

Rats' lever pressing was studied on three schedules of reinforcement: fixed interval, response-initiated fixed interval, and fixed ratio. In testing, concentration of the milk reinforcer was varied within each session. On all schedules, duration of the postreinforcement pause was an increasing function of the concentration of the preceding reinforcer. The running rate (response rate calculated by excluding the postreinforcement pauses) increased linearly as a function of the preceding magnitude of reinforcement on fixed interval, showed slight increases for two of the three animals on response-initiated fixed interval, and did not change systematically on fixed ratio. In all cases, the overall response rate either declined or showed no effect of concentration. The major effect of increasing the reinforcement magnitude was in determining the duration of the following postreinforcement pause, and changes in the response rate reflected this main effect.     

Light reinforcement in the rat: The effects of continuous and discontinuous periods of apparatus familiarization

The effects of continuous and discontinuous periods of apparatus familiarization on light reinforcement in rats were examined. A previous finding that the light reinforcement effect is greater with longer pretest periods in the dark box was confirmed by comparing 270 min and 30 min periods in the box prior to testing 24 h later. A discontinuous period of 9 daily 30 min sessions, however, produced a bigger effect than the 270 min continuous period. It was concluded that the degree of familiarization with the apparatus is a more important factor than length of time per se in the dark in determining the effectiveness of light as a reinforcer.     

Aftereffects of reinforcement on variable-ratio schedules

On each of variable-ratio 10, 40, and 80 schedules of reinforcement, when rats' lever-pressing rates were stable, the concentration of a liquid reinforcer was varied within sessions. The duration of the postreinforcement pause was an increasing function of the reinforcer concentration, this effect being more marked the higher the schedule parameter. The running rate, calculated by excluding the postreinforcement pause, was unaffected by concentration. The duration of the postreinforcement pause increased with the schedule parameter, but the proportion of the interreinforcement interval taken up by the pause decreased. Consequently, the overall response rate was an increasing function of the schedule parameter; i.e., it was inversely related to reinforcement frequency, contrary to the law of effect. The running rate, however, decreased with the reinforcement frequency, in accord with the law of effect. When 50% of reinforcements were randomly omitted, the postomission pause was shorter than the postreinforcement pause, but the running rate of responses was not affected.     

Species differences in temporal control of behavior

Temporal control of rats' and pigeons' responding was analyzed and compared in detail on fixed-interval and fixed-time schedules with parameters of 30, 60, and 120 seconds. On fixed-time schedules, rats' responding decreased greatly or ceased, whereas pigeons continued to respond, especially on low schedule values. The running rate of responses (calculated by excluding the postreinforcement pause) was related to the duration of the preceding postreinforcement pause for rats but not for pigeons. Changes in response rate in successive segments of the interval were best described by normal curves. The relationship between midpoints of the normal curves and schedule value was a power function, with an exponent of less than one for pigeons but greater than one for rats. These differences could be explained in terms of a basic difference between the key-peck and lever-press responses, the two being differently affected by the response-eliciting properties of food.     

Channel,temporal, and composite uncertainty in the detection and recognition of auditory and visual signals

In a 2AFC detection task, channel and temporal uncertainty were separately shown to produce decrements in the detectability of auditory and visual signals. The observed effect of channel uncertainty suggests that Ss are capable of using an “attentional” or “performance-compensation” strategy. This finding is discussed in relation to a “multiple-observation” model for channel uncertainty. Recognition measures were taken where appropriate and gave some support to the hypothesized attentional strategy. Under composite uncertainty conditions both types of uncertainty were presented simultaneously; the results indicated that any interaction effect was small, relative to the separate effects of channel and temporal uncertainty.     

Self-Defeating Behavior Workshops: Systems Approach for Hard-to-Serve Veterans

For the past two and one-half years, the self-defeating behavior (SDB) theory has been applied to a population of veterans who had a history of problems in job training, vocational placement, and academic settings. A group-therapy structure meeting eight times during a four-week period is the basic approach of the SDB seminar. In conjunction with the SDB seminar, a variety of support people and agencies have combined efforts to develop a systems approach to helping the veterans eliminate behaviors that are self-defeating. Results from the systems approach have been excellent.     

Measuring the Intrapersonal Component of Psychological Empowerment: Confirmatory Factor Analysis of the Sociopolitical Control Scale

The Sociopolitical Control Scale (SPCS) is a widely used measure of the intrapersonal component of psychological empowerment. Confirmatory factor analyses (CFA) were conducted with data from two samples to test the hypothesized structure of the SPCS, the potential effects of method bias on the measure’s psychometric properties, and whether a revised version of the scale (SPCS-R) yielded improved model fit. Sample 1 included 316 randomly selected community residents of the Midwestern United States. Sample 2 included 750 community residents of the Northeastern U.S. Results indicated that method bias from the use of negatively worded items had a significant effect on the factor structure of the SPCS. CFA of the SPCS-R, in which negatively worded items were rephrased so that all statements were positively worded, supported the measure’s hypothesized two-factor structure (i.e., leadership competence and policy control). Subscales of the SPCS-R were found reliable and related in expected ways with measures of community involvement. Implications of the study for empowerment-based research and practice are described, and strategies to further develop the SPCS are discussed.     

Oh {delta}{iota}{alpha with oxia}! How is Romans 4:25 to be Understood?

How are we to understand the difficult expression ‘raisedfor our justification’ (Romans 4:25b)? The clue lies intaking seriously the two + accusatives in Romans 4:23. Therethey express a parallel between the promise of righteousness‘for him (Abraham)’ and the same kind of promise,still valid ‘for us’. This same emphasis shouldbe taken into 4:25, ‘for us ... for us.’ Such areading is not only backed up by the Isaiah 53 echo and thecontents of Romans 5, it also serves to explain the meaningof Romans 4:25b. Abraham was given an opportunity for ‘righteousness-producingfaith’ through a tension between ‘under-realizedreality’ and God's faithfulness (vv.18–22). Throughthe resurrection of Jesus Christ, the same opportunity is nowafforded to ‘us’.