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21.
When the process of publication favors studies with smallp-values, and hence large effect estimates, combined estimates from many studies may be biased. This paper describes a model for estimation of effect size when there is selection based on one-tailedp-values. The model employs the method of maximum likelihood in the context of a mixed (fixed and random) effects general linear model for effect sizes. It offers a test for the presence of publication bias, and corrected estimates of the parameters of the linear model for effect magnitude. The model is illustrated using a well-known data set on the benefits of psychotherapy.Authors' note: The contributions of the authors are considered equal, and the order of authorship was chosen to be reverse-alphabetical.  相似文献   
22.
以实验鉴定了常规的启动效应计量方法的有效性程度,并为客观地计量启动效应,创用了“超意识广度法”、“二次比较法”等.结果发现:(1)如被试数量较少,以不同补笔率为“基线值”所求得的启动效应之间发生显著差异的可能性存在;(2)超意识广度法能克服“阈下呈现刺激法”“分散注意法”的不足,为内隐记忆提供有利的识记情境;(3)“二次比较法”能为正常人内隐记忆的存在提供更为直接、可靠的证据,并能客观、精确地计量启动效应。  相似文献   
23.
The study examines the relative merits of a noncompatibility and a restructuring explanation of the recurrent empirical finding that a prominent attribute looms larger in choices than in judgments. Pairs of equally attractive options were presented to 72 undergraduates who were assigned to six conditions in which they performed (1) only preference judgments or choices, (2) preference judgments or choices preceded by judgments of attractiveness of attribute levels, or (3) preference judgments or choices accompanied by think-aloud reports. The results replicated the prominence effect for choices, but a prominence effect was also found for preference judgments. In accordance with the restructuring explanation, the think-aloud protocols indicated that options were more often restructured in choices than in preference judgments. However, restructuring could not explain the prominence effect observed for preference judgments. A modified compatibility hypothesis is offered as an alternative explanation.  相似文献   
24.
对听觉条件下中文字词劣效果的问题进行了实验考察,结果发现:在文章听点作业中,被试对高、低频目标字词语音的正误判断量存在着显著性差别,前者较后者成绩差,表现出字词劣效果的现象;在单字词的听点作业中,未发现被试对高、低频目标字词语音正误判断量方面的显著性差别;无论在文章还是单字词的听点作业中,被试对高、低频目标字词语音的正误判断量均比较低下,表明语音知觉的范畴性特征对字词语音的辩认准确性具有较大影响。  相似文献   
25.
Key pecking of four birds was reinforced with food according to a two-component multiple variable-interval 1-minute variable-interval 4-minute schedule. In addition, key pecking was punished by a brief shock according to a variable-interval 30-second schedule during both components of the multiple schedule. The intensity of the shock was varied. For all birds, punishment had a stronger suppressive effect on the responding maintained by the leaner food schedule, and the ratio of responding during the two components of the multiple schedule became closer to the ratio of reinforcement as shock intensity was increased, as the relative law of effect predicts. At the higher shock intensity, there was some evidence that the ratio of responses overmatched the ratio of reinforcements.  相似文献   
26.
Warmup in avoidance as a function of time since prior training   总被引:2,自引:2,他引:0       下载免费PDF全文
On avoidance procedures, rats and pigeons typically show warmup effects, characterized by improving performance within sessions and loss of the improvement (“warmup decrement”) between sessions. Between-session losses were examined by varying the time between periods of avoidance training. In one experiment, rats lived fulltime in conditioning chambers while intermission intervals were varied. In a second experiment, the animals lived in home cages between sessions; timeout intervals were introduced at midession, producing recurrence of warmup in the second half-session. In both experiments, the warmup decrements increased substantially as the timeout or intersession intervals were increased from zero to 30 minutes. With intervals of 60 or 120 minutes, the decrements approached or exceeded those obtained with intervals of a day or more. When avoidance was interposed between appetitive sessions, the appetitive responding was disrupted, but this seemed unrelated to the warmup or to the proficiency of avoidance. The warmup in avoidance shares characteristics with transient punishment effects, with the Kamin effect, and with habituation phenomena, but it is premature to assume that they reflect common processes.  相似文献   
27.
28.
Interpretations regarding the effects of exogenous and endogenous variables on endogenous variables in linear structural equation systems depend upon the convergence of a matrix power series. Convergence depends upon the eigenvalues of the structural coefficient matrix. The test for convergence developed by Jöreskog and Sörbom is shown to be only sufficient, not necessary and sufficient.  相似文献   
29.
In a two-key concurrent variable-interval schedule (using pigeons), if the reinforcement frequency for one response is held constant while that for the other is increased, the rate of response on the constant key decreases. The immediate reinforcement for key pecking can usually be conceptualized as the change from a condition in which the key light is on and the food hopper light is off to one in which the key light is off and the hopper light is on. The prechange condition is associated with a delay to food of one-half the average interreinforcement interval in effect during this condition. The postchange condition is associated with a delay to food of about .5 seconds. The programming of additional reinforcement results in a decrease in the delay to food associated with the prechange stimulus condition, and thus a decrease in the value of the improvement that results from the change. This would appear to be analogous to a decrease in the amount of reinforcement, and thus sufficient explanation for the decrease in the rate of the response.  相似文献   
30.
Three pigeons learned to peck four colors in a particular sequence, regardless of how these colors were positioned on four response keys and without feedback following each response. This demonstrates that serial learning is possible in subprimate animals.  相似文献   
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