Deduction chains for common knowledge

Deduction chains represent a syntactic and in a certain sense constructive method for proving completeness of a formal system. Given a formula , the deduction chains of are built up by systematically decomposing into its subformulae. In the case where is a valid formula, the decomposition yields a (usually cut-free) proof of . If is not valid, the decomposition produces a countermodel for . In the current paper, we extend this technique to a semiformal system for the Logic of Common Knowledge. The presence of fixed point constructs in this logic leads to potentially infinite-length deduction chains of a non-valid formula, in which case fairness of decomposition requires special attention. An adequate order of decomposition also plays an important role in the reconstruction of the proof of a valid formula from the set of its deduction chains.     

The effect of sex labels on adults' knowledge of infant development

The present study investigated the influence of sex label of an infant on adult men's and women's knowledge of infant development. Two hundred thirty nine adults were asked to indicate on a questionnaire the age at which they believed infants were first able to perform a variety of developmental skills. The 56 skills equally represented cognitive, language, motor, and personal-social behaviors. One third of the adults received a questionnaire about girls, one third about boys, and one third about babies (sex label not provided). Each of the three groups had equal numbers of men and women. Contrary to previous findings, results indicated that the sex label of the infant did not affect adults' ratings of behaviors. This finding is discussed with respect to current cognitive-social psychological conceptualizations of gender stereotypes.Portions of this paper were presented at the annual meeting of the Early Childhood Education Conference, Kent, Ohio, October 1984, and the American Psychological Association, Los Angeles, California, August 1985.     

Relativized common knowledge for dynamic epistemic logic

Relativized common knowledge is a generalization of common knowledge proposed for public announcement logic by treating knowledge update as relativization. Among other things relativized common knowledge, unlike standard common knowledge, allows reduction axioms for the public announcement operators. Public announcement logic can be seen as one of the simplest special cases of action model logic (AML). However, so far no notion of relativized common knowledge has been proposed for AML in general. That is what we do in this paper. We propose a notion of action model relativized common knowledge for action model logic, and study expressive power and complete axiomatizations of resulting logics. Along the way we fill some gaps in existing expressivity results for standard relativized common knowledge.     

The roles of meaningfulness and prior knowledge in younger and older adults' memory performance

Meaningfulness and prior knowledge can have differing effects on both metamemory and memory performance. Personally relevant information may be deemed more meaningful, which often can serve as a mediating factor in memory performance. Additionally, information that is congruent with prior knowledge has been shown to be judged as easier to remember and often is better remembered. Both of these effects are most pronounced in older adults. The current study aimed to examine the impact of meaningfulness and prior knowledge on age‐related differences in metamemory (i.e., judgments of learning) and memory performance (i.e., recall and recognition) by manipulating subjective a priori familiarity and personal relevance using age‐relevant study materials (i.e., a student loan application and a Medicare application). Recall metamemory and recall performance results indicate that older adults, but not younger adults, were able to utilize meaningfulness and prior knowledge to boost memory performance.     

Attention and the acquisition of new knowledge: their effects on older adults' associative memory deficit

Older adults experience a selective associative memory deficit by demonstrating intact item memory relative to impaired associative memory when compared with younger adults. Age-related deficits in associative memory have been suggested to arise from declines in attentional resources, and the role of attention during encoding and retrieval in associative memory for words and their spatial locations was investigated in the current experiment. Additionally, the tendency of younger and older adults to use knowledge acquired during encoding to improve their associative memory judgments through a strategic associative memory process was also investigated. Younger and older adults studied a list of words with each word belonging to one of four categories, which followed one of four mathematical probability structures for their presentation. Older adults exhibited intact item memory and impaired associative memory relative to full attention younger adults. In addition, both older and younger adults demonstrated an ability to engage in strategic associative memory, by learning and later using the probability structure introduced at study to guide their associative memory judgments. In contrast, dividing the attention of younger adults during encoding impaired item memory, associative memory and strategic associative memory, whereas dividing attention at retrieval did not result in similar deficits. These data add to a growing body of literature demonstrating older adults to exhibit a selective associative memory deficit that is not simulated by dividing the attention of younger adults at encoding or retrieval. Furthermore, younger and older adults maintain the ability to use new knowledge to guide their associative judgments.     

Young adults' knowledge of politics: evaluating the role of socio-cognitive variables using structural equations

The aim of this study was to create an explanatory model that allows analyzing the predictive power of a set of variables related to political knowledge; more specifically, to analyze the relationship between the education level of young adults and the variables, interest in politics and internal political efficacy. We also analyzed the combined relationship between these variables, together with age, and political knowledge. We worked with a sample group of 280 young adults between the ages of 18-30 from the city of Córdoba (Argentina). The data was subjected to a structural equation modelling SEM analysis, which allowed for the corroboration of the following hypotheses: the higher the education level, the more the interest in politics; the higher the education level, the better the perception of internal political efficacy; the higher the education level, the more the political knowledge; the more the interest in politics, the more the political knowledge; and the better the perception of internal political efficacy, the more interest in politics. Moreover, the following hypotheses could not be verified: the older an individual, the more the political knowledge; and the better the perception of internal political efficacy, the more the political knowledge. The model obtained allows for discussion of the explanatory value of these socio-cognitive variables.     

The relationship between high performance and knowledge about how to master cooperation situations

This paper applies the expertise approach to cooperation settings and examines high performers' knowledge about cooperation situations. We argue that high performers know more about how to address cooperation situations than do moderate performers. Specifically, we assume that they know more about problem analysis, about how to address the task, the cooperation partner and the cooperation partners' task approach. We report findings of two empirical studies in which study participants responded to scenario situations. The first study based on a sample of 39 software professionals showed that high performers were superior with respect to overall knowledge and specific knowledge aspects. The second study based on a sample of 62 engineers partially replicated these findings. High performers' better knowledge of cooperation situations could not be explained by years of experience or perspective taking. However, situation‐specific experiences partially accounted for the relationship between performance level and knowledge. Copyright © 2002 John Wiley & Sons, Ltd.     

Older adults' use of metacognitive knowledge in source monitoring: spared monitoring but impaired control

While episodic memory declines with age, metacognitive monitoring is spared. The current study explored whether older adults can use their preserved metacognitive knowledge to make source guesses in the absence of source memory. Through repetition, words from two sources (italic vs. bold text type) differed in memorability. There were no age differences in monitoring this difference despite an age difference in memory. Older adults used their metacognitive knowledge to make source guesses but showed a deficit in varying their source guessing based on word recognition. Therefore, older adults may not fully benefit from metacognitive knowledge about sources in source monitoring.     

Young children's knowledge about the influence of thoughts on emotions in rule situations

Four‐year‐olds, 5‐year‐olds, and adults (N = 48) listened to stories featuring characters that experienced one of four types of thoughts after deciding to transgress or comply with a rule: thoughts about desires, rules, future negative outcomes, or future punishment. Participants predicted and explained the characters’ emotions. Results showed that young children, as with adults, predicted positive emotions for willpower and negative emotions for transgression at low rates for the think‐desire trials, and at high rates for the think‐rule and think‐future trials. They also modified their emotion explanations in line with the focus of characters’ thoughts. These data provide unprecedented evidence that young children can reason flexibly about emotions in rule situations when provided explicit, salient information about people's thoughts.     

Magnitude knowledge: the common core of numerical development

The integrated theory of numerical development posits that a central theme of numerical development from infancy to adulthood is progressive broadening of the types and ranges of numbers whose magnitudes are accurately represented. The process includes four overlapping trends: (1) representing increasingly precisely the magnitudes of non‐symbolic numbers, (2) connecting small symbolic numbers to their non‐symbolic referents, (3) extending understanding from smaller to larger whole numbers, and (4) accurately representing the magnitudes of rational numbers. The present review identifies substantial commonalities, as well as differences, in these four aspects of numerical development. With both whole and rational numbers, numerical magnitude knowledge is concurrently correlated with, longitudinally predictive of, and causally related to multiple aspects of mathematical understanding, including arithmetic and overall math achievement. Moreover, interventions focused on increasing numerical magnitude knowledge often generalize to other aspects of mathematics. The cognitive processes of association and analogy seem to play especially large roles in this development. Thus, acquisition of numerical magnitude knowledge can be seen as the common core of numerical development.     

Aphasic adults' use of heuristic and structural linguistic cues for sentence analysis

Eight aphasic adults with relatively preserved auditory comprehension and 12 normal adults were tested for their ability to analyze sentences in which the functional relations between the verb and nouns was either directly reflected by word order expectancies, or marked by a functor or non-NVN word order. The subjects' task was to designate the agent of each sentence. Results indicated that aphasics utilize word order expectancies but are impaired in their ability to exploit functors and particularly, word order markers for sentence analysis. Results are discussed in terms of aphasics' use of heuristic versus structural linguistic cues for interpreting sentences.     

Variation in individuals' semantic networks for common knowledge is associated with false memory

Three experiments assessed the relationships between false memories of words and their degree of connectedness within individual semantic networks. In the first two experiments, participants studied associated word lists (e.g., hot, winter, ice), completed a recognition test that included related nonstudied words (e.g., cold, snow), and then rated the semantic relatedness of all word pairs including studied and nonstudied words. In the third experiment, the task order was reversed; participants completed pairwise ratings and then, two weeks later, completed the false memory task. The relatedness ratings were analysed using the Pathfinder scaling algorithm. In all experiments, items that an individual falsely recognized had higher semantic Pathfinder node densities than those items correctly rejected.     

Variation in individuals' semantic networks for common knowledge is associated with false memory

Three experiments assessed the relationships between false memories of words and their degree of connectedness within individual semantic networks. In the first two experiments, participants studied associated word lists (e.g., hot, winter, ice), completed a recognition test that included related nonstudied words (e.g., cold, snow), and then rated the semantic relatedness of all word pairs including studied and nonstudied words. In the third experiment, the task order was reversed; participants completed pairwise ratings and then, two weeks later, completed the false memory task. The relatedness ratings were analysed using the Pathfinder scaling algorithm. In all experiments, items that an individual falsely recognized had higher semantic Pathfinder node densities than those items correctly rejected.