Time-series analysis in operant research

A time-series method is presented, nontechnically, for analysis of data generated in individual-subject operant studies, and is recommended as a supplement to visual analysis of behavior change in reversal or multiple-baseline experiments. The method can be used to identify three kinds of statistically significant behavior change: (a) changes in score levels from one experimental phase to another, (b) reliable upward or downward trends in scores, and (c) changes in trends between phases. The detection of, and reliance on, serial dependency (autocorrelation among temporally adjacent scores) in individual-subject behavioral scores is emphasized. Examples of published data from the operant literature are used to illustrate the time-series method.     

The Zax Information Profile: a measure of college adjustment

Evaluated the effectiveness of the Zax Information Profile (ZIP), a personality test based on general fund of information, in discriminating between college students who sought mental health services and those who did not, Three successive classes of freshmen students at the Eastman School of Music of the University of Rochester were administered the ZIP. Help-seeking students were matched with non-help-seeking students for sex, age, and intellectual ability. The hypothesis that ZIP scores would differentiate between these two groups was supported by the data. The potential use of the ZIP as a predictor of college adjustment and as a useful entrance screening device was discussed.     

Clock control of human performance on avoidance and fixed-interval schedules

The avoidance and fixed-interval performances of human subjects were studied in two experiments. Addition of time-correlated stimuli (added clock) improved behavioral efficiency, since response rates decreased without decreases in reinforcement rates. Response-dependent display of the clock maintained a second, observing response and reductions in clock duration weakened such observing behavior. Generally, the reinforcing properties of the clock were more apparent with the avoidance than with the fixed-interval schedule, a finding attributed to temporal cues already provided by delivery of the fixed-interval reinforcers. Reduced rates of the main response when the clock was dependent on an observing response were more than offset by rates of the observing response in the majority of subjects. Thus, the results do not support an interpretation of the reinforcing properties of added clocks simply in terms of work reduction.     

Food deliveries during the pause on fixed-interval schedules

Pigeons were trained on fixed-interval schedules of food delivery. In Experiments I and II, the fixed interval was initiated by the previous fixed-interval reinforcer; in Experiment III, the fixed interval was initiated by the first key peck following the preceding fixed-interval reinforcer (a chain fixed-ratio one, fixed-interval schedule). During the postreinforcement pause, variable-time schedules delivered food independent of any specific response. Rate of food delivery during the pause had only small effects on pause duration in Experiments I and II. In Experiment III, however, pause duration increased systematically with the rate of food delivery during the pause. These data suggest that the momentary proximity to reinforcement delivered via the fixed-interval schedule exerts potent control over pause termination. Additional analysis revealed that pause termination was unaffected by the intermittent delivery of food during the pause. Such data suggest that the temporal control by fixed-interval schedules is highly resistant to interference.     

指南是怎样制定的?

最近在制定临床实践指南的方法上发生了一些变化,这深刻地影响着医学保健的质量和成本,远远超过前后10年所有新出现的诊疗手段的作用.人们预期,制定指南方法的改变影响着指南的内容,进而对未来几十年中成千上万的临床决策发挥指导作用.目前,制定指南的方法所经历的改变代表了医学赖以存在的知识基础发生了变化.     

欧麦尔传略

先知穆罕默德归真后,在伊斯兰教旗帜下联合起来的阿拉伯人进入了一个新的发展时期。第一任哈里发艾布·伯克的功绩在于重新统一了阿拉伯半岛,并开拓了疆土。但艾布·伯克执政两年就归真了,继承这一伟大事业并使伊斯兰教发展成为一个国际性宗教的,是第二任哈里发欧麦尔。他为哈里发国家的巩固和发展做出了巨大的贡献。     

同一的真与符合的真北大核心CSSCI

真之符合论指的是一个命题是真的,当且仅当它符合一个事实;真之同一论指的是一个命题是真的,当且仅当它是一个事实。真之符合论强调命题与事实的符合,真之同一论强调命题与事实的同一。一些真之同一论的倡导者同样是真之符合论的支持者,从一定意义上来讲,真之同一论是真之符合论的发展与简化。M.大卫对真之符合论和真之同一论做出了比较细致的分析,并且提出了一些十分有意义的看法。     

The perception of closed flat knots and completion by folding

The aim of the present research was to study a well-defined set of line drawings that have never been analyzed before, and that are perceived as closed flat knots (CFKs). These knots are obtained by folding two-dimensional laminae. From this study it emerged that the perception of CFKs is always accompanied by a type of amodal completion, which had not previously been studied, and which we have called "completion by folding". It occurs when three quadrilaterals are so arranged that they look like a sheet of paper folded around one of them, partly occluded and partly occluding. Two experiments were carried out on this phenomenon revealing that a three-level stratification is produced in the completion by folding that facilitates unification between occluded figures, even when current models do not foresee such a perceptual solution, either because the distance between the two figures that become a unit is too big (experiment ) or because the slope between the two figures is not favorable (experiment 2). A third experiment, which took up the problem of the perception of CFKs, revealed the following: (1) Besides the prototype CFK, obtained by the interlacing of a rectangular lamina, there is a theoretically infinite class of CFKs. (2) The drawing of all the possible closed flat knots involves geometrically precise rules. (3) Not all feasible knots with these rules are seen as such. (4) Only the knots with characteristics of alignment and regularity are recognized as knots. (5) The closed flat knots are seen as the result of a transformation which the figure undergoes. This evidence constitutes a remarkable perceptual problem, discussed with reference to the recent theories of amodal completion.