Misconceptions about incline speed for nonlinear slopes

In 3 experiments, college students provided qualitative predictions about a marble's speed along nonlinear inclines. When predicting the outcome of a race between identical marbles along differently shaped ramps, most students predicted incorrectly that the shorter path was necessarily quicker (the shorter-quicker belief). When comparing instantaneous speed at 2 points, most students predicted incorrectly that incline speed depended on the slope at that point (the slope-speed belief). A final experiment provides evidence that the slope-speed belief reflects a deeper fallacy regarding the resistance encountered while traversing inclines and lifting objects. This fallacy also predicts the prevalent belief that heavier objects fall faster than lighter objects during incline descent or free fall.     

Analyzing the dynamics of free recall: An integrative review of the empirical literature

Relatively few experiments have measured the time course of free recall from episodic or semantic memory. Of those that have, most report that cumulative recall is a negatively accelerated exponential (or hyperbolic) function that is characterized by two properties: asymptotic recall and rate of approach to asymptote. The most common measure of free recall performance (viz., the number of items recalled) provides a reasonably good estimate of asymptotic recall if a relatively long recall period is used (which is rare), but the effect of experimental manipulations on the rate of approach to asymptote cannot be determined without timing when recall responses occur. The research reviewed herein suggests that the rate of approach to asymptote may offer an estimate of the breadth of search through long-term memory. The search in question, unlike most of those investigated in the memory literature, is unique in that it requires minutes rather than milliseconds to complete.     

Avoidance of overlearning characterises the spacing effect

The spacing of a fixed amount of study time across multiple sessions usually increases subsequent test performance—a finding known as the spacing effect. In the spacing experiment reported here, subjects completed multiple learning trials, and each included a study phase and a test. Once a subject achieved a perfect test, the remaining learning trials within that session comprised what is known as overlearning. The number of these overlearning trials was reduced when learning trials were spaced across multiple sessions rather than massed in a single session. In addition, the degree to which spacing reduced overlearning predicted the size of the spacing effect, which is consistent with the possibility that spacing increases subsequent recall by reducing the occurrence of overlearning. By this account, overlearning is an inefficient use of study time, and the efficacy of spacing depends at least partly on the degree to which it reduces the occurrence of overlearning.     

Effects of maternal negativity and of early and recent recurrent depressive disorder on children's false belief understanding

Research has shown that children of depressed mothers are at risk for problems in a variety of developmental domains; however, little is known about the effects of maternal depression on children's emerging understanding of false beliefs. In this study, 3 false belief tasks were administered to 5-year-old children whose mothers had either met criteria for major depressive disorder within the first 20 months of the child's life (n = 91) or had never been depressed (n = 50). Significant difficulties in performance were found among the children of depressed mothers, especially those whose mothers had experienced early and recent recurrent depressive disorder. Regardless of diagnostic status, children whose mothers exhibited negativity during problem-solving tasks administered at an earlier developmental period also were less likely to demonstrate false belief understanding. These effects remained even after child verbal ability was controlled.     

When does feedback facilitate learning of words?

Some researchers have suggested that although feedback may enhance performance during associative learning, it does so at the expense of later retention. To examine this issue, subjects (N = 258) learned Luganda-English word pairs. After 2 initial exposures to the materials, subjects were tested on each item several times, with the presence and type of feedback varying between subjects. A final test followed after 1 week. Supplying the correct answer after an incorrect response not only improved performance during the initial learning session--it also increased final retention by 494%. On the other hand, feedback after correct responses made little difference either immediately or at a delay, regardless of whether the subject was confident in the response. Practical and theoretical implications are discussed.     

The effects of interleaved practice

Previous research shows that interleaving rather than blocking practice of different skills (e.g. abcbcacab instead of aaabbbccc) usually improves subsequent test performance. Yet interleaving, but not blocking, ensures that practice of any particular skill is distributed, or spaced, because any two opportunities to practice the same task are not consecutive. Hence, because spaced practice typically improves test performance, the previously observed test benefits of interleaving may be due to spacing rather than interleaving per se. In the experiment reported herein, children practiced four kinds of mathematics problems in an order that was interleaved or blocked, and the degree of spacing was fixed. The interleaving of practice impaired practice session performance yet doubled scores on a test given one day later. An analysis of the errors suggested that interleaving boosted test scores by improving participants' ability to pair each problem with the appropriate procedure. Copyright © 2009 John Wiley & Sons, Ltd.     

Congruency effects in part-list cuing inhibition.

In demonstrations of part-list cuing inhibition, subjects who are shown a subset of studied list words recall fewer noncue words than subjects not shown such part-list cues. We propose that part-list inhibition is governed in part by an incongruency principle: Inhibition occurs to the extent that part-list cues induce a retrieval framework different from that used to encode list items. In Experiment 1, word lists were studied followed by a test of free recall either without cues, or with cue words serially organized to be either congruent or incongruent with the order of studied items. In Experiments 2-4, cues consisted of every second study item in the original presentation order (congruent ones) or reordered to form famous names or familiar idioms that had been hidden in the study list (incongruent cues). More part-list inhibition was observed with incongruent cues than congruent cues in all 4 experiments.