An investigation of perfectionism,mental health,achievement, and achievement motivation in adolescents

This study examined the relationship of perfectionism with measures of achievement and achievement motivation and mental health aspects of depression and self‐esteem in high school students. Participants were 123 tenth‐ through twelfth‐grade students. Results of multiple regression analyses indicated that students' personal standards were significant predictors of academic achievement. Students' personal standards also significantly predicted achievement motivation. Analyses of the relationship between perfectionism and depression and self‐esteem found that as students' personal standards increased, their levels of depression decreased and self‐esteem increased. Furthermore, when students experienced a discrepancy between their personal standards and actual performance, their depression levels increased and self‐esteem decreased. © 2000 John Wiley & Sons, Inc.     

Central suboptimal H∞ filtering for nonlinear polynomial systems with multiplicative noise

This paper presents the central finite-dimensional H_∞ filter for nonlinear polynomial systems with multiplicative noise, that is suboptimal for a given threshold γ with respect to a modified Bolza-Meyer quadratic criterion including the attenuation control term with the opposite sign. In contrast to the previously obtained results, the paper reduces the original H_∞ filtering problem to the corresponding optimal H₂ filtering problem, using the technique proposed in [1]. The paper presents the central suboptimal H_∞ filter for the general case of nonlinear polynomial systems with multiplicative noise, based on the optimal H₂ filter given in [31]. The central suboptimal H_∞ filter is also derived in a closed finite-dimensional form for third (and less) degree polynomial system states. Numerical simulations are conducted to verify performance of the designed central suboptimal filter for nonlinear polynomial systems against the central suboptimal H_∞ filters available for polynomial systems with state-independent noise and the corresponding linearized system.     

Optimal filtering over linear observations with unknown parameters

This paper presents the optimal filtering and parameter identification problem for linear stochastic systems over linear observations with unknown parameters, where the unknown parameters are considered Wiener processes. The original problem is reduced to the filtering problem for an extended state vector that incorporates parameters as additional states. The resulting filtering system is bilinear in state and linear in observations. The obtained optimal filter for the extended state vector also serves as the optimal identifier for the unknown parameters. Performance of the designed optimal state filter and parameter identifier is verified for both, positive and negative, parameter values.     

Re/presenting a gender equity project: Contrasting visions and versions

This article provides three different accounts of a gender-equity project in a Grade 10 science class. The three stories, a realist one of victory over oppression, a realist story of inclusion, and a reflexive story of identity, illustrate different rhetorical forms for representing research and different assumptions about gender, pedagogy, equity, and the representation of data. Any version of a project can only be a partial account. As teachers and researchers, our commitments and investments influence our questions, understandings, and representations. The content and form of our stories imply particular relationships with an audience. Those responsible for policy tend to favor realist stories that reduce complexity and increase certainty. Others may be more interested in stories that portray complexity and highlight the need for judgments in particular contexts. No one form is appropriate for all occasions. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 859–876, 1998.     

Cognitive assessment of function knowledge

Two theories of assessing function knowledge were compared for intuitive physics. The choice assessment theory, derived from Piaget, presents subjects with two physical situations, each specified by the values of two physical variables; subjects choose the situation which will yield the greater value of a dependent variable. Functional measurement presents subjects with a single physical situation; subjects make a quantitative estimate of the dependent variable. Forty subjects made both choice and functional measurement responses for two situations of intuitive physics. The choice theory showed substantial frequencies of stepwise rules, implying that subjects failed to integrate the two given physical variables. Functional measurement, in contrast, showed that most subjects integrated the two variables, following exact addition or multiplication rules. It is concluded that functional measurement gives a more correct assessment of function knowledge and should be useful in science instruction. J Res Sci Teach 34: 359–376, 1997.