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991.
992.
填埋已成为我国城市生活垃圾的一种主要处理方式。对填埋过程中产生的垃圾渗滤液进行分析评价并进行处理,已成为防止其造成二次污染的一个必要环节。基于对洛阳市盘龙冢垃圾填埋场渗滤液处理处置的必要性和紧迫性的分析,采用单项污染指数法对其水质进行分析评价,对其污染现状进行分析和讨论,并对其处理现状进行了深入调查。 相似文献
993.
Michael L. Thomas Gregory G. Brown Virginie M. Patt John R. Duffy 《Educational and psychological measurement》2021,81(1):155
The adaptation of experimental cognitive tasks into measures that can be used to quantify neurocognitive outcomes in translational studies and clinical trials has become a key component of the strategy to address psychiatric and neurological disorders. Unfortunately, while most experimental cognitive tests have strong theoretical bases, they can have poor psychometric properties, leaving them vulnerable to measurement challenges that undermine their use in applied settings. Item response theory–based computerized adaptive testing has been proposed as a solution but has been limited in experimental and translational research due to its large sample requirements. We present a generalized latent variable model that, when combined with strong parametric assumptions based on mathematical cognitive models, permits the use of adaptive testing without large samples or the need to precalibrate item parameters. The approach is demonstrated using data from a common measure of working memory—the N-back task—collected across a diverse sample of participants. After evaluating dimensionality and model fit, we conducted a simulation study to compare adaptive versus nonadaptive testing. Computerized adaptive testing either made the task 36% more efficient or score estimates 23% more precise, when compared to nonadaptive testing. This proof-of-concept study demonstrates that latent variable modeling and adaptive testing can be used in experimental cognitive testing even with relatively small samples. Adaptive testing has the potential to improve the impact and replicability of findings from translational studies and clinical trials that use experimental cognitive tasks as outcome measures. 相似文献
994.
A number of psychometricians have suggested that parallel analysis (PA) tends to yield more accurate results in determining the number of factors in comparison with other statistical methods. Nevertheless, all too often PA can suggest an incorrect number of factors, particularly in statistically unfavorable conditions (e.g., small sample sizes and low factor loadings). Because of this, researchers have recommended using multiple methods to make judgments about the number of factors to extract. Implicit in this recommendation is that, when the number of factors is chosen based on PA, uncertainty nevertheless exists. We propose a Bayesian parallel analysis (B-PA) method to incorporate the uncertainty with decisions about the number of factors. B-PA yields a probability distribution for the various possible numbers of factors. We implement and compare B-PA with a frequentist approach, revised parallel analysis (R-PA), in the contexts of real and simulated data. Results show that B-PA provides relevant information regarding the uncertainty in determining the number of factors, particularly under conditions with small sample sizes, low factor loadings, and less distinguishable factors. Even if the indicated number of factors with the highest probability is incorrect, B-PA can show a sizable probability of retaining the correct number of factors. Interestingly, when the mode of the distribution of the probabilities associated with different numbers of factors was treated as the number of factors to retain, B-PA was somewhat more accurate than R-PA in a majority of the conditions. 相似文献
995.
Entrenched socioeconomic inequalities in achievement have been observed in international assessments for decades, with previous research suggesting that these inequalities may be exacerbated by differentiation in the opportunities provided to various social groups. Much previous research in this field has been US-based or subject to measurement issues. This study investigated socioeconomic inequalities in outcomes and opportunities using four cycles of international assessment data across 78 countries. Further, the paper questions whether inequalities in opportunities are related to inequalities in outcomes. The findings indicate global social inequalities in mathematics and science outcomes, while inequality of opportunity was particularly concentrated in economically advanced countries. Little evidence of the perpetuation of socioeconomic inequality in achievement through differentiated educational provision was found. 相似文献
996.
Our aim was to explore higher education students’ response and self-regulatory processes plus the relationship between these, as evidenced in two types of performance-based critical thinking tasks included in the Collegiate Learning Assessment (CLA+) International instrument. The data collection consisted of 20 cognitive laboratories. The data were analyzed using a qualitative approach. The tasks were found to trigger different response and self-regulatory processes. Overall, the performance task evoked more holistic processes than the selected-response questions, in which students’ processes were more question-oriented. The results also indicated the entanglement of students’ response and self-regulation processes. Three self-regulation groups were identified. Students with versatile self-regulation skills were able to complete the task thoroughly, whereas students with moderate self-regulation skills faced challenges in monitoring and evaluating their performance. Students who were lacking in self-regulation struggled both with the task as a whole and their own progress. Implications for higher education are discussed. 相似文献
997.
Focusing on evaluating students’ performance in basic math classrooms, the researchers in this study examined the impact of alternative assessments on learning outcomes in fourth grade Palestinian classrooms. Representing a large sector of education in the Palestinian territories, fourth grade students were randomly selected to participate in the study in which they participated in various math instructional and assessment activities throughout multiple lessons and cycles. Alternative assessment approaches were used including student self- assessment, peer assessment, and teacher assessment in terms of three main achievement levels to measure the extent to which students learned the math concepts by recall and remembrance, ability to apply, and making inferences. Mixed Design ANOVA measures were used to analyze and interpret the results which showed significant trends and correlations across the four cycles of math instruction and indicated that alternative authentic assessment methods have had a positive impact on students’ learning and application of math. Implications for integrating authentic assessment measures as well as peer and self- assessments were drawn in light of the promising outcomes of augmenting student motivation and developing critical life-long skills. 相似文献
998.
Immediate Knowledge of Results (KR) feedback at the task level may motivate test takers by showing that their answers matter. Appealing feedback cues may help to prevent negative emotions in lower performers who receive a higher amount of negative feedback. In this experiment, we varied the presence of KR feedback and the feedback delivery mode in a 1 × 5 between-subjects design (i.e., no feedback vs. text, color, sound, or animation feedback) to investigate effects on learning outcomes and affective-motivational measures. Our sample included 661 fifth and sixth graders who solved two computer-based multiple-choice science tests. First, students worked on an 18-item treatment test (with experimental feedback manipulation). Students repeatedly rated their effort, enjoyment, pride, and boredom during the test, as well as their expectancy of success and attainment value after the test. Subsequently, they worked on a posttest (without feedback) that assessed recall and near-transfer learning. All KR feedback conditions significantly increased recall, but there was no evidence for near-transfer learning. Feedback had a significant, negative effect on attainment value, whereas significant interactions between the feedback conditions and students’ treatment performance revealed that feedback effects on several affective-motivational dimensions (i.e., expectancy of success, enjoyment, pride, and boredom) were performance-dependent. Feedback benefited higher performers’ motivation and affect but showed negative effects on some affective-motivational measures for lower performers. The pattern of results indicated that color/sound/animation feedback may have reduced the effect of performance on emotional feedback perception to some extent. However, none of the feedback conditions improved affective-motivational outcomes independent of students’ performance. 相似文献
999.
数学是一门与生活紧密相连的学科,俗语有云:“学会数理化,走遍全天下。”其中数学位于首位,足以见得数学知识能够很好地解决实际问题。利用生活化教学策略进行数学教学,能够让小学生对数学内容产生一定的学习兴趣与好奇心,并且能够有效提升学生对数学知识的重视程度,学生愿意主动学习数学,其综合能力才能够有效提升起来。为了实现上述教学效果,本文主要研究小学数学教学生活化的有效策略。 相似文献
1000.
生活处处有数学。无论是从新时期数学课程改革的要求来看,还是从教育教学理论分析或者小学生的全面发展来看,将生活情境教学法用于小学数学教学都具有重要意义。本文首先从数学学科的特点出发,简要分析生活情境教学法应用研究的必要性;然后从新课程标准、教育学理论依据、学生全面发展三个方面分析生活情境教学法用于小学数学教学实践的依据,进而探究相关的实践方法。 相似文献