可满足性问题的归约技术

通过一个恰当的归约变换,可以将一个CNF公式变换为另一个具有某种特殊结构或性质的公式,使其两者具有相同的可满足性。一个典型的归约是将一般的CNF公式变换为3．GVF公式。通过构造一些恰当的工具,可以将公式类变换为所要求的正则类。极小不可满足公式具有一个临界特征,公式本身不可满足,从原始公式中删去任意一个子句后得到的公式可满足。我们提供了一种归约技术,通过构造恰当的极小不可满足公式作为工具,将公式类变换为具有正则结构的公式类。研究正则结构的公式的复杂性及性质很有意义。如,将一个从3．CNF公式变换为（3,4）一CNF公式,这里（3,4）一CNF公式是指公式中每个子句的长度恰为3,每个变元出现的次数恰为4。因此,（3,4）．SAT是一个NP．完全问题,并且正N-部图的诸多良好性质对于研究正则结构的SAT问题具有许多潜在的作用。     

The pleasure of possessions: affective influences and personality in the evaluation of consumer items

What is the role of affect in the way people perceive and evaluate their material possessions? Participants induced to feel good or bad estimated the subjective and objective value of a number of consumer items they owned or wanted to own. Participants also completed the Openness to Feelings (OF) scale. As expected, mood had no effect on objective evaluations. However, we found a significant interaction between personality (OF) and mood on subjective evaluations. Individuals scoring high on OF showed a clear mood congruent pattern: They made more positive evaluations of consumer items when in a positive rather than negative mood. In contrast, people scoring low on OF showed an opposite, mood‐incongruent bias. Openness to Feelings moderated the mood effects regardless of whether the mood was induced using an autobiographical or a video mood induction procedure, and regardless of whether the items were owned or merely desired. The results are interpreted in terms of the cognitive mechanisms responsible for mood effects on consumer judgments, and the role of personality variables in moderating these effects is discussed. The implications of the findings for contemporary affect‐cognition theories, and for our understanding of the variables influencing consumer judgments are considered. Copyright © 2000 John Wiley & Sons, Ltd.     

Arousal and recognition memory: The effects of impulsivity,caffeine and time on task

Systematic changes in performance on memory tasks have been observed as a function of the number of prior items or lists learned. In an attempt to determine whether this was an ‘attentional’ phenomenon the effect of arousal (as indexed by Impulsivity and manipulated by caffeine) on memory performance was examined. One hundred college students were given either 4 mg of caffeine/kg body weight or a placebo and then shown four lists (two 24-item and two 80-item) of four letter words. A forced-choice recognition test for the last 20 items was given immediately after each list. The performance of the high impulsives who were given a placebo (least aroused subjects) declined as a function of the number of prior lists learned. Low impulsives (more aroused) showed significantly less decline. Caffeine significantly improved recognition memory especially on the final lists. Decrements in memory performance, as a function of number of prior litsts, are thus reduced by the same variables which reduce vigilance decrements. It is suggested that common explanations will be required.     

Recognition and frequency judgments in young and elderly adults

Three experiments examined frequency judgments and recognition memory in young and elderly adults. Subjects were presented a long list of words at either a 5-s rate (Experiments 1 & 3) or a 1-s rate (Experiment 2), after which frequency-judgment and recognition memory tasks were administered. Either an absolute (Experiments 1 & 2) or a relative (Experiment 3) frequency-judgment task was used. The recognition test, which involved repeated tests of some items, involved either one incorrect item paired with each correct item (Experiments 1 & 2), or four incorrect items (Experiment 3). Age-related differences in frequency judgments, for the more frequently presented items, were found in all three experiments. For the recognition scores, the predicted interaction between age and successive tests was found only in Experiment 3. The results were interpreted within the framework of age-related differences in elaborative encoding and in distractibility to irrelevant stimuli.     

Implicit and explicit memory without awareness

Summary Three experiments are reported which investigate the conscious status of subjects during an implicit-memory test. In all experiments the subjects either named each visually presented target item or generated each item from an anagram in a first phase of incidental learning. In a second phase, they were either given a visual word-stem completion task as an implicit-memory test or given a recognition task (Experiment 1), or a cued-recall task (Experiments 2 and 3) as explicit-memory tests. Finally, in a third phase the subjects were required to make decisions about the input status (i. e., they had to decide whether the item was present in the first phase) as well as about the output status of information (i. e., they had to decide whether the item had been completed, recognized or recalled in the second phase). A generation effect (i. e., generated items were remembered better than named items) was evident in the recognition and recall data, but only for items whose recognition or recall was accompanied by conscious recollection of their previous occurrence in the study list. Judgments about the input status were more precise, given that items had been consciously recognized or recalled rather than completed. The same pattern of findings was observed for judgments about the output status. The results are interpreted as evidence that subjects in implicit-memory tests are less aware of the fact that some of their productions are relevant to prior experiences. In addition, they are less aware of the fact that they are retrieving information from their memories. However, the same state of nonawareness may be present in explicit-memory tests, as was revealed by the performance of subjects on those items whose recognition or recall was not accompanied by conscious recollection.     

Information Processing and Exchange in Mediated Groups

This study examined whether features of mediated group discussion were related to participator judgments. Prior to discussion, participants (N = 138) were asked to memorize a list of qualifications for each of 3 hypothetical candidates for a faculty position. Each list contained shared (given to all members) and unique (given to just 1 member) information. Participants, working in 3‐person groups, then interacted via 1 of 2 computer text environments to choose the best candidate. Following discussion, participants rated each other on a set of participator assessment items. Discussions were coded for units that contained shared or unique information. The analysis revealed that shared contributions were related only to self‐assessment of participation. Unique contributions had a complex relation with self‐assessments—they were positively associated with such judgments only when partners infrequently provided unique information. Technology affected in a variety of ways the relation between the discussion variables and participator assessments. Discussion focuses on the relation between information pooling and interaction, as well as on the role of technology in group process.     

Effects of meaningfulness and organization on problem solving and computability judgments

When subjects were required to calculate answers for computable problems and answer questions, an interaction was found corresponding to that obtained by Kieras and Greeno (1975) from judgments of computability. With nonsense formulas, much longer times were required to identify noncomputable problems than to compute answers, with a much smaller difference when formulas consisted of meaningful concepts. The better performance on noncomputable problems and questions with meaningful formulas corroborates an interpretation that those items test the connection of algorithms with general conceptual knowledge. Finally, it was found that for relatively complex problems, solution times and time to judge computability were longer if nonsense formulas were learned in separate sets than if they were learned in a single set; however, no such effect was found with meaningful formulas. It was concluded that learning conditions influenced the integration of cognitive structure in the case of nonsense formulas, while subjects were able to adjust organization of the meaningful formulas.     

On the independence of judged frequencies for items presented in successive lists*

In an experiment examining retroactive interference effects in a frequency-judging task, all Ss were presented with a list of words occurring varying numbers of times according to either a massed- or distributed-practive (MP or DP) schedule. They were then asked to judge how often each word had occurred. Following this, Ss were given one of four types of second tasks a second list with different items followed by a frequency-judging task for that list (Condition New): a second list with items repeated from the first list but with different frequencies for each item, while either maintaining items as either MP or DP items (Condition Same) or switching MP items to DP, and vice versa (Condition Reverse): followed by a frequency-judging task for the second-list frequencies only: or a puzzle task for the amount of time required for second-list presentation and judgment in the other conditions (Condition None). Finally, all Ss were asked to recall List 1 frequencies, List 2 frequencies were less discriminable in Conditions Same and Reverse than in Condition New. Recall of List 1 frequencies, however, was not different for these three groups, but was poorer than in List 2 frequency judgments were not independent of List 1 frequencies.     

Effects of orienting task,spacing of repetitions,and list context on judgments of frequency

Subjects were given an unexpected frequency judgment test following a list of words in which items were presented either two, three, and five times or three, five, and seven times, with a spacing of 0, 2, 16, or 32 items between repetitions. During list presentation, they either rated the imagery value of each word or made continuous frequency estimates. Postlist frequency judgments of words presented three and five times were higher for the list containing words of Frequency 7, and judgments were also higher following the imagery rating task. Continuous judgments were unaffected by the list context and showed different effects of spacing than postlist judgments. The results provide support for the operation of response bias factors in the frequency judgment task and are relevant to theoretical interpretations of the spacing effect.     

Hindsight bias in insight and mathematical problem solving: Evidence of different reconstruction mechanisms for metacognitive versus situational judgments

This article presents two experiments that used insight and mathematical problems to investigate whether different factors would affect hindsight bias on metacognitive and situational judgments. In both studies, participants initially rated their likelihood of solving each problem within a certain amount of time (metacognitive judgments) and rated the importance of each component of the problem for finding the solution (situational judgments). Next, participants attempted to solve each problem. In Experiment 1, all participants were given solution feedback information, but in Experiment 2, participants were not given any solution feedback. After 1 week, participants were asked to recall their original judgments. Hindsight bias was assessed by comparing the initial with the final ratings. Insight problems and math problems showed different patterns of hindsight bias effects on the metacognitive and situational judgments. The results suggest that two competing models of hindsight effects are actually complementary explanations for judgment reconstruction on different types of judgment tasks.     

Public Confession and Forgiveness

ABSTRACT In this article, we report investigations of four role-playing experiments and one laboratory manipulation that examine the effects of confession on forgiveness and other related judgments. The basic paradigm in the simulation studies was to reveal that a political figure or student in a class confessed either following or not following an accusation, or denied personal responsibility for the act. Among the variables manipulated were the attributions for the wrongdoing and the spontaneity of the confession. The dependent variables in one or more investigations included the perceived personal character of the trangressor, attributions of responsibility for the act, affective reactions of sympathy and anger, forgiveness, and behavioral judgments such as sanctioning and voting likelihood. In the laboratory manipulation study, a mixed-motive game setting was used in which a confederate confessed to having prior knowledge that resulted in his winning the game. We then examined whether this admission influenced subsequent cooperation and competition, as well as the other players' perceptions of the confederate's personality and character. Confession was found to have strong beneficial effects, particularly when given without a prior accusation and in ambiguous causal situations.     

Direct versus indirect tests of memory for source: judgments of modality

We studied the relation between performance on direct versus indirect tests of memory for modality. Subjects read or heard words in a mixed list and then were tested by visual perceptual identification (the indirect test) and direct report of items as read, heard, or new. There was a dependent relation between perceptual identification performance and modality judgments, in accord with the hypothesis that subjects base their judgments of modality on relative perceptual fluency. In Experiment 2, we attempted to change the degree of dependence by providing subjects with an alternative basis for modality judgments. Subjects given a mnemonic to encode modality exhibited less dependence between perceptual identification performance and modality judgments than did subjects who encoded modality incidentally. The relation between direct and indirect tests of memory for source characteristics depends on the basis used for each.     

Revising explications of common sense through dialogue: Thirty-six psychological theorems

An explication of common sense is an attempt to formulate a part of the ordinarily unformulated system of implications shared by all members of a given culture, familiar with a given context. Thirty-six alleged common sense formulations relating to Bandura's theory of self-efficacy were used. Students were asked 1) to give a prediction involving each theorem, 2) to judge whether or not an alternative prediction is conceivable, 3) to judge whether or not an explanation based on the theorem is acceptable, and 4) to judge whether or not an explanation based on the negation of the theorem is acceptable. The average consensus on these four types of judgments was respectively 93%, 80%, 92%, and 96%. A group of respondents were interviewed about the shortcomings of the formulations. The theorems were revised to incorporate these criticisms and, hence, are expected to yield higher consensus.     

The role of observer attitudes in judgments of blame in cases of wife assault

This study examines the importance of observer characteristics in determining blame in cases of wife assault. Four independent variables (observer's attitudes toward sex roles, observer sex and age, and victim behavior) were assessed for their influence on the blaming judgments of 128 participants. Subjects completed a questionnaire that contained demographic items and six wife assault vignettes that varied in level of victim provocation (low or high). Questions about blame of the husband and wife followed each vignette. An attitudes toward women scale (AWS-B) was then administered. The main hypothesis, that subjects with traditional attitudes would blame the victim more and the perpetrator less for the assault than their egalitarian counterparts, was supported, as was the prediction of an interaction between provocation and AWS-B. The results are discussed in light of the role of observer attitudes in attribution models.     

Frequency judgements: the problem of defining a perceptual event

In four experiments the conditions under which frequency judgments reflect the relative frequency of complex perceptual events were explored. Subjects viewed a series of 4 x 4 grids each containing seven items, which were letters and numbers in one of four typefaces. Later judgments of the relative frequency with which particular letters appeared in particular typefaces were unaffected by a warning about an upcoming frequency judgment task, but were affected by both the time available for processing the stimuli and the nature of the cover task subjects engaged in while viewing the grids. Frequency judgments were poor when exposure durations were less than 2 s and when the cover task directed subjects' attention merely to the locations of the items within the grids. Frequency judgments improved when the cover task directed subjects' attention to the identity of the stimuli, especially to the conjunction of letter and typeface. The results suggest that frequency estimation of complex stimuli may be possible only for stimuli that have been processed as phenomenal objects.     

Metacognition for strategy selection during arithmetic problem-solving in young and older adults

We examined participants’ strategy choices and metacognitive judgments during arithmetic problem-solving. Metacognitive judgments were collected either prospectively or retrospectively. We tested whether metacognitive judgments are related to strategy choices on the current problems and on the immediately following problems, and age-related differences in relations between metacognition and strategy choices. Data showed that both young and older adults were able to make accurate retrospective, but not prospective, judgments. Moreover, the accuracy of retrospective judgments was comparable in young and older adults when participants had to select and execute the better strategy. Metacognitive accuracy was even higher in older adults when participants had to only select the better strategy. Finally, low-confidence judgments on current items were more frequently followed by better strategy selection on immediately succeeding items than high-confidence judgments in both young and older adults. Implications of these findings to further our understanding of age-related differences and similarities in adults’ metacognitive monitoring and metacognitive regulation for strategy selection in the context of arithmetic problem solving are discussed.     

EFFECT OF GROUP PERFORMANCE ON SUBSEQUENT INDIVIDUAL PERFORMANCE:

Abstract— Does group discussion and deliberation on one issue or task influence the members' decisions or opinions on other issues? In contrast to past research looking solely at changes in responses to the same item discussed by the group, this study examined whether group interaction results in members changing the way they make judgments on related items in the future. The results show that group discussion and consensus on one set of judgments led to a significant convergence of judgmental strategies that extended to a related (but different) set of judgments the members made later as individuals.     

The effect of testing procedure on remember-know judgments

Remember-know (R-K) judgments are commonly used to assess conscious recollection of the study episode during recognition. We varied whether participants judged items as R, K, or new (one-step) or first made an old-new judgment and then made the R-K judgment (two-step). The one-step group had a higher R hit rate and K false alarm rate than did the two-step group. In addition, the K responses of the one-step group did not reliably discriminate between old and new items. When a “guess” response category was available, both groups were able to discriminate old and new items using the K response; however, K responses remained more accurate in the two-step condition. R responses appeared to be relatively immune to the effects of testing procedure when the guess category was provided. This suggests that, under some conditions, the R label can reliably indicate a distinct form of recognition memory, suggesting that allowing participants to use a guess response may help them to confine their R-K judgments to confidently recognized items. When participants are not given the option of making a guess response, they may use the R-K distinction to indicate the trace strength of the memory.     

Auditory pattern recognition by untrained listeners

Earlier work with unpracticed Ss has indicated that identification (naming) of the temporal order of components within repeated sequences consisting of three or four unrelated sounds cannot be accomplished when the item durations are 200 msec or less. In the present experiment, separate groups of 30 unpracticed Ss were required to teil whether alternated sequences, each consisting of reiterated presentations of the same three or four successive items, were in identical or permuted order. Naming of the order within the sequences was not required. Accuracy of same/different judgments was significantly better than chance when all items lasted 200 msec. Changing the duration of each item in one of the two sequences above or below 200 msec made the task more difficult. These results, together with other evidence, suggest that: (1) identification of order and recognition of auditory temporal patterns may represent fundamentally different processes, and (2) recognition may involve matching of “temporal templates.”     

Relationship between students' self-assessment of their capabilities and their teachers' judgments of students' capabilities in mathematics problem-solving

The study examined the judgments made by four seventh-grade mathematics teachers of their 107 students' competence in solving mathematics problems. Simultaneously, the 107 students made self-efficacy judgments about their capability in solving mathematics problems. The two sets of judgments were tested for predicting students' mathematics performance. Also, students' prior mathematics achievement was studied for its influence on both teachers' and students' judgments and students' mathematics performance. Teachers were asked to make judgments of each student for every mathematics problem solved. Results were consistent with prior research indicating that students' mathematics self-efficacy beliefs were highly predictive of their performance. Path analysis indicated that the mathematics teachers' judgments were also highly predictive of students' performance and self-efficacy. In turn, these variables predicted students' postperformance judgments. Combining students' self-efficacy judgments and teachers' judgments of students increased predictiveness for students' mathematics performance. Educational implications were also discussed.