Team adaptation to an unforeseen system failure: Limits of the potential aids of shared knowledge and standardized communication

The present study investigates the potential benefits of a team’s shared knowledge and standardized communication in adapting to an unforeseen change by combining literature on adaptation and team performance. Each of 20 teams performed a dynamic team task and was suddenly confronted with a simulated partial system breakdown. Results show that a methodological framework designed to describe performance adaptation to an unforeseen change in individuals can also be used to model performance adaptation in teams. The system failure was followed by a performance drop and a subsequent period of gradual performance recovery. Accuracy of teams’ shared knowledge correlated positively with performance before and after the change, confirming and extending the literature on shared mental models. However, the amount of knowledge similarity did not aid teams in adapting to the unforeseen system breakdown. In addition, improving teams’ standardized communication had no damping effect on the sudden performance drop and neither helped them during the subsequent recovery period. These results show that even though shared knowledge and efficient communication are of high value to team performance and success, these characteristics are limited in aiding adaptive team performance after unforeseen unique changes that force team members to update their strategies.     

Satisfiability Decay along Conjunctions of Pseudo-Random Clauses

k-SAT is a fundamental constraint satisfaction problem. It involvesS(m), the satisfaction set of the conjunction of m clauses,each clause a disjunction of k literals. The problem has manytheoretical, algorithmic and practical aspects. When the clauses are chosen at random it is anticipated (butnot fully proven) that, as the density parameter m/n (n thenumber of variables) grows, the transition of S(m) to beingempty, is abrupt: It has a "sharp threshold", with probability1 – o(1). In this article we replace the random ensemble analysis by apseudo-random one: Derive the decay rule for individual sequencesof clauses, subject to combinatorial conditions, which in turnhold with probability 1 – o(1). This is carried out under the big relaxation that k is not constantbut k = log n , or even r log log n . Then the decay of S isslow, "near-perfect" (like a radioactive decay), which entailssharp thresholds for the transition-time of S below any givenlevel, down to S = .     

Estimation and visualization of confusability matrices from adaptive measurement data

We present a simple but effective method based on Luce’s choice axiom [Luce, R.D. (1959). Individual choice behavior: A theoretical analysis. New York: John Wiley & Sons] for consistent estimation of the pairwise confusabilities of items in a multiple-choice recognition task with arbitrarily chosen choice-sets. The method combines the exact (non-asymptotic) Bayesian way of assessing uncertainty with the unbiasedness emphasized in the classical frequentist approach.We apply the method to data collected using an adaptive computer game designed for prevention of reading disability. A player’s estimated confusability of phonemes (or more accurately, phoneme-grapheme connections) and larger units of language is visualized in an easily understood way with color cues and explicit indication of the accuracy of the estimates. Visualization of learning-related changes in the player’s performance is considered.The empirical validity of the choice axiom is evaluated using the game data itself. The axiom appears to hold reasonably well although a small systematic violation is observable for the smallest choice-set sizes.     

On the statistical and theoretical basis of signal detection theory and extensions: Unequal variance, random coefficient, and mixture models

Basic results for conditional means and variances, as well as distributional results, are used to clarify the similarities and differences between various extensions of signal detection theory (SDT). It is shown that a previously presented motivation for the unequal variance SDT model (varying strength) actually leads to a related, yet distinct, model. The distinction has implications for other extensions of SDT, such as models with criteria that vary over trials. It is shown that a mixture extension of SDT is also consistent with unequal variances, but provides a different interpretation of the results; mixture SDT also offers a way to unify results found across several types of studies.     

Still cautious: Personality characteristics of extremely low birth weight adults in their early 30s

Extremely low birth weight survivors (ELBW; <1000 g) display a personality style characterized by cautiousness, shyness, and risk aversion in their 20s. We examined whether non-impaired ELBW survivors were still more cautious than their normal birth weight (NBW) peers at ages 30–35 and assessed the stability of this personality characteristic across approximately a decade in the oldest known cohort of ELBW survivors. Of the 154 participants tested at ages 22–26, 111 (i.e., 72%) of them returned approximately 10 years later [i.e., 69% (49/71) ELBW and 75% (62/83) NBW], and once again they completed the Eysenck Personality Questionnaire-Revised (EPQ-R). We created the same theoretically and empirically derived composite measure of cautiousness at each visit by summing the EPQ-R psychoticism scale (reverse scored) and the EPQ-R lie scale. We found that ELBW adults reported higher cautiousness than their NBW counterparts at ages 30–35. We also found that levels of cautiousness remained stable over approximately 10 years in both groups. Our findings suggest that individuals born at ELBW were more cautious than NBW peers and that this personality characteristic remained stable into their early 30s. The present study appears to be the first empirical demonstration of personality stability among adult ELBW survivors.     

Perceiving vocal age and gender: An adaptation approach

Aftereffects of adaptation have revealed both independent and interactive coding of facial signals including identity and expression or gender and age. By contrast, interactive processing of non-linguistic features in voices has rarely been investigated. Here we studied bidirectional cross-categorical aftereffects of adaptation to vocal age and gender. Prolonged exposure to young (~ 20 yrs) or old (~ 70 yrs) male or female voices biased perception of subsequent test voices away from the adapting age (Exp. 1) and the adapting gender (Exp. 2). Relative to gender-congruent adaptor-test pairings, vocal age aftereffects (VAAEs) were reduced but remained significant when voice gender changed between adaptation and test. This suggests that the VAAE relies on both gender-specific and gender-independent age representations for male and female voices. By contrast, voice gender aftereffects (VGAEs) were not modulated by age-congruency of adaptor and test voices (Exp. 2). Instead, young voice adaptors generally induced larger VGAEs than old voice adaptors. This suggests that young voices are particularly efficient gender adaptors, likely reflecting more pronounced sexual dimorphism in these voices. In sum, our findings demonstrate how high-level processing of vocal age and gender is partially intertwined.     

Gender Differences and Cognition Among Older Adults

The more replicated findings about gender difference in cognitive performance suggest female superiority on visuomotor speed and language ability and male superiority on mechanical and visuospatial tasks. Generally, group strengths found in the early school years become more established at adolescence and remain stable through adulthood. The current study tested whether the patterns established in the early years remained among 30 adult subjects. We also utilized a series of exploratory analyses to determine if observed gender differences were impacted by the covariance present between all cognitive tests. Results suggest that although the patterns established in the early years remain stable through time for males, the established patterns for females are altered with age. Our findings are compelling in supporting a male advantage on visuospatial tasks among older adults. These findings are discussed in terms of common variance between test instruments as a possible source of difference. Our finding that the gender effect tended to increase when common variance was controlled argues that this methodology may enhance the ability to detect domain specific effects.     

初中生函数概念发展的特点

本研究通过测验法对北京市六所中学的８０２名初一至初三的学生进行考察,研究了初中生函数要领的发展水平及其特点,结果表明,初中三个年级学生函数要领的发展,从总体上看,随着看级的增高呈上升的发展趋势,但年级结学生函数概念发展的影响不显著,制约 初中学生函数的概念发展水平的关键是,学生所受教育的质量,学生主要以接受教育的方式来获得函数概念。