An investigation of the partial-assignment completion effect on students' assignment choice behavior

This study was designed to investigate the partial assignment completion effect. Seventh-grade students were given a math assignment. After working for 5 min, they were interrupted and their partially completed assignments were collected. About 20 min later, students were given their partially completed assignment and a new, control assignment that contained the same number of equivalent problems that were incomplete on their partially completed assignment. Students were told that they would have to complete an assignment but could choose which assignment they completed. Significantly more students chose their partially completed assignment. Theoretical and applied implications and directions for future research are discussed.     

Choice and foraging

In Experiment 1, six naive pigeons were trained on a foraging schedule characterized by different states beginning with a search state in which completion of a fixed-interval on a white key led to a choice state. In the choice state the subject could, by appropriate responding on a fixed ratio of three, either accept or reject the schedule of reinforcement that was offered (either a variable-interval five-second or a variable-interval 20-second). If the subject accepted the schedule, it entered a “handling state” in which the appropriate variable-interval schedule was presented. Completion of the variable-interval schedule produced food. The independent variable was the fixed-interval value in the search state, and the dependent variable was the rate of acceptance of the long variable-interval in the choice state. Experiment 2 was identical except that the search state required completion of a variable-interval, instead of a fixed-interval, schedule. The rate of acceptance of the long variable-interval schedule in both experiments was a direct function of the length of the search state, in accordance with both optimality theory and the delay-reduction hypothesis.     

FAITH,BELIEF, AND THE COMPATIBILITY OF RELIGION AND SCIENCE

Recent attacks on the compatibility of science and religion by the “militant modern atheists” (Jerry Coyne, Richard Dawkins, Daniel Dennett, Sam Harris, Christopher Hitchens) have posed serious challenges for anyone who supports the human importance of religious faith (particularly their identification of “faith” with “believing without evidence”). This article offers a critical analysis of their claims compared with those who do not equate faith with belief. I conclude that (i) the militant modern atheist interpretation of faith undervalues transformative religious experiences, (ii) that more people of faith hold it for this reason than their opponents acknowledge, and (iii) that meaningful dialogue between religion and science is both possible and desirable.     

图词间隔时间影响口语词汇产生中语义效应的机制：图词干扰范式研究

口语词汇产生过程中存在语义抑制和语义促进效应, 可能发生在概念准备和词汇选择或者后词汇水平阶段。本研究采用图画-词汇干扰实验任务, 变化图画与词汇出现点之间的时间间隔(stimulus onset asynchrony, SOA), 运用脑电技术考察口语词汇产生中语义效应发生的时间进程。结果显示, 当SOA为0 ms时表现出语义抑制效应, 语义效应发生在词汇选择阶段(344~418 ms); 当SOA为-400 ms时, 语义效应发生在概念准备阶段(0~76 ms)和词汇选择阶段(274~390 ms); 460~594 ms时间窗口内的语义效应可能表明讲话者对语义信息的自我监测。词汇产生中存在语义促进效应和抑制效应的权衡, 影响了行为结果中语义效应的方向, 上述发现支持了口语词汇产生的词汇竞争假说。     

Characteristics of Unintentional Movements by a Multijoint Effector

The authors explored the phenomenon of unintentional changes in the equilibrium state of a multijoint effector produced by transient changes in the external force. The subjects performed a position-holding task against a constant force produced by a robot and were instructed not to intervene voluntarily with movements produced by changes in the robot force. The robot produced a smooth force increase leading to a hand movement, followed by a dwell time. Then, the force dropped to its initial value leading to hand movement toward the initial position, but the hand stopped short of the initial position. The undershoot magnitude increased linearly with the peak hand displacement and exponentially with dwell time (time constant of about 1 s). For long dwell times, the hand stopped at about half the total distance to the initial position. The authors interpret the results as consequences of a drift of the referent hand coordinate. Our results provide support for back-coupling between the referent and actual body configurations during multijoint actions and produce the first quantitative analysis of this phenomenon. This mechanism can also explain the phenomena of slacking and force drop after turning visual feedback off during accurate force production task.     

Tests for equality of several alpha coefficients when their sample estimates are dependent

In a variety of measurement situations, the researcher may wish to compare the reliabilities of several instruments administered to the same sample of subjects. This paper presents eleven statistical procedures which test the equality ofm coefficient alphas when the sample alpha coefficients are dependent. Several of the procedures are derived in detail, and numerical examples are given for two. Since all of the procedures depend on approximate asymptotic results, Monte Carlo methods are used to assess the accuracy of the procedures for sample sizes of 50, 100, and 200. Both control of Type I error and power are evaluated by computer simulation. Two of the procedures are unable to control Type I errors satisfactorily. The remaining nine procedures perform properly, but three are somewhat superior in power and Type I error control.A more detailed version of this paper is also available.     

Statements of Method and Teaching: The Case of Socrates

In this paper, I ponder the question of whether Socrates follows a method of investigation — the method of hypothesis — which he advocates in Plato's Phaedo. The evidence in the dialogue suggests that he does not follow the method, which raises additional questions: If he fails to do so, why does he articulate the method? Does his statement of method affect his actions or is it mainly forgotten? Although Socrates is a fictional character, his actions in the Phaedo suggests questions about the function of espoused methods in actual situations.     

A molecular analysis of choice on concurrent-chains schedules.

Six pigeons responded on concurrent-chains schedules with either independent or interdependent equal variable-interval schedules in the initial links and unequal variable-interval schedules, always in a 2:1 ratio, in the terminal links. Relative response rates in the initial links increased across conditions as initial-link duration was shortened and decreased across conditions as terminal-link duration was shortened, replicating previous findings. Responses in the initial links were recorded in 5-s bins, and local or molecular relative response rates were calculated in order to ascertain how relative response rate varied as a function of time since the onset of the initial links. Two distinct molecular patterns were found. With interdependent initial links, relative response rates for the preferred key were elevated for the first 10 or 20 s of the initial links and then declined to an asymptotic value. With independent initial links, a negative recency effect was found similar to that reported by Killeen (1970). These two molecular patterns were related to the different momentary reinforcement probabilities resulting from independent and interdependent scheduling.     

Accuracy versus speed in the generalized effort of learning-disabled children

Reinforcement of effortful performance in a given academic task has been found to increase the subsequent performance of other academic tasks. The learned-effort hypothesis assumes that individuals learn which dimensions of task performance are correlated with reinforcement of high effort, and generalize across tasks. Therefore, reinforcement of increased effort in a given dimension of one task should result in greater generalized effort in the same dimension of transfer performance than in another dimension. In accord with this view, preadolescent learning-disabled students who received points for high reading accuracy subsequently produced more accurate drawings and stories than did students whose points had been based upon high reading speed or upon mere completion of the reading task. Students who received points for high reading speed subsequently constructed stories more quickly than did children whose points had been based upon high reading accuracy or upon reading-task completion. Consistent with the more explicit and frequent feedback for accuracy than for speed in most academic tasks, generalized accuracy was much more durable than generalized speed.     

A model and algorithm for multidimensional scaling with external constraints on the distances

A method for externally constraining certain distances in multidimensional scaling configurations is introduced and illustrated. The approach defines an objective function which is a linear composite of the loss function of the point configurationX relative to the proximity dataP and the loss ofX relative to a pseudo-data matrixR. The matrixR is set up such that the side constraints to be imposed onX's distances are expressed by the relations amongR's numerical elements. One then uses a double-phase procedure with relative penalties on the loss components to generate a constrained solutionX. Various possibilities for constructing actual MDS algorithms are conceivable: the major classes are defined by the specification of metric or nonmetric loss for data and/or constraints, and by the various possibilities for partitioning the matricesP andR. Further generalizations are introduced by substitutingR by a set ofR matrices,R _i ,i=1, ...r, which opens the way for formulating overlapping constraints as, e.g., in patterns that are both row- and column-conditional at the same time.