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91.
The primary aim was to examine the criterion and construct validity and test–retest reliability of the Lifesource XL-18 pedometer (A&D Medical, Toronto, ON, Canada) for measuring steps under controlled and free-living activities. The influence of body mass index, waist size and walking speed on the criterion validity of XL-18 was also explored. Forty adults (35–74 years) performed a 6-min walk test in the controlled condition, and the criterion validity of XL-18 was assessed by comparing it to steps counted manually. Thirty-five adults participated in the free-living condition and the construct validity of XL-18 was assessed by comparing it to Yamax SW-200 (YAMAX Health & Sports, Inc., San Antonio, TX, USA). During the controlled condition, XL-18 did not significantly differ from criterion (P > 0.05) and no systematic error was found using Bland–Altman analysis. The accuracy of XL-18 decreased with slower walking speed (P = 0.001). During the free-living condition, Bland–Altman analysis revealed that XL-18 overestimated daily steps by 327 ± 118 than Yamax (P = 0.004). However, the absolute percent error (APE) (6.5 ± 0.58%) was still within an acceptable range. XL-18 did not differ statistically between pant pockets. XL-18 is suitable for measuring steps in controlled and free-living conditions. However, caution may be required when interpreting the steps recorded under slower speeds and free-living conditions.  相似文献   
92.
The use of structural equation modeling (SEM) in communication research has become increasingly popular in recent years, with SEM being commonly used as the primary method of data analysis in studies published within the field’s journals. However, despite its widespread use, there are persistent misapplications of SEM in published empirical studies in the communication sciences. Of these types of misuse, the most troubling are those related to the exploitation of flexibilities in data collection and analysis. Given the number of decisions that must be made when analyzing and reporting structural equation models, decisions which often remain undisclosed, the potential for researchers to exploit flexibilities in SEM research is high. To assess the extent of this problem, as well as the more longstanding types of misuse (i.e., omission of information and disclosed “bad practice”) identified by prior studies, we undertake a methodical review of studies employing structural equation modeling within major journals in the field of communication between the years 2007 and 2011. Articles were coded on the characteristics of the sample, characteristics of the model tested, as well as for various potential problems that we defined a priori. The most serious issues are identified, and recommendations for future standards in SEM research are suggested.  相似文献   
93.
The candidate chooses projects for his or her ability to establish credentials as a performance technologist. The clearer the links between actions and improved performance for the client, the stronger the case each example makes. Candidates will need to show this linkage between contribution and outcome for each project used in preparing the submission package.  相似文献   
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95.
A considerable amount of social identity research has focused on race and racial identity, while gender identity, particularly among Black adolescents, remains underexamined. The current study used survey data from 183 Black adolescent males (13–16 years old) to investigate the development and relation between racial and gender identity centrality and private regard, and how these identities impact adjustment over time. It was found that dimensions of racial and gender identity were strongly correlated. Levels of racial centrality increased over time while gender centrality, and racial and gender private regard declined. In addition, racial and gender identity uniquely contributed to higher levels of psychological well‐being and academic adjustment. These findings are discussed within the context of existing identity theories and intersectionality theory.  相似文献   
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Development of early math skill depends on a prerequisite level of cognitive development. Identification of specific cognitive skills that are important for math development may not only inform instructional approaches but also inform assessment approaches to identifying children with specific learning problems in math. This study investigated the specific cognitive correlates of math problem solving across early grade levels (1–4) while controlling for basic calculation skills. As expected, basic calculation skill was a significant predictor of math problem solving across the entire sample. However, the addition of cognitive measures almost doubled the variance explained (R2 = .61). Additionally, only select cognitive variables contributed to the prediction of math problem solving, and these variables change in importance as children develop higher‐level math skills. Results are discussed within a developmental model, which emphasizes the increasing importance of abstract code representations required in higher levels of math performance.  相似文献   
98.
Ageing anxiety is the expression of peoples' fear of ageing (Lynch, 2000 Lynch, S. M. (2000). Measurement and prediction of aging anxiety. Research on Aging, 22(5), 533.[Crossref], [Web of Science ®] [Google Scholar]). Despite greater longevity in the population, there is a lack of research into this aspect of life (Lasher &; Faulkender, 1993 Lasher, K. P., &; Faulkender, P. J. (1993). Measurement of aging anxiety: Development of the Anxiety about Aging Scale. The International Journal of Aging &; Human Development, 37(4), 247259.[Crossref], [PubMed], [Web of Science ®] [Google Scholar]). This research explored fears of ageing across four dimensions: Fear of Old People, Physical Appearance, Psychological Concerns, and Fear of Losses. Three hundred and forty eight participants aged 18–88 participated in an online survey. Findings were: (a) men and women have different fears of ageing; (b) greater quality contact is related to less ageing anxiety; (c) poor health is related to greater ageing anxiety, (d) ageism, defined by Nelson (2005 Nelson, T. D. (2005). Ageism: Prejudice against our feared future self. Journal of Social Issues, 61(2), 207221.[Crossref], [Web of Science ®] [Google Scholar]) as prejudice toward ageing is positively correlated with ageing anxiety. The implications of these findings are that better quality contact and more positive attitudes toward ageing are associated with less ageing anxiety. As such, possible key target areas in developing appropriate interventions are provided, with hope to prepare adults of all ages for the inevitable—life is a terminal illness, so enjoy while you can.  相似文献   
99.
In recent years, there has been a strong push to transform STEM education at K-12 and collegiate levels to help students learn to think like scientists. One aspect of this transformation involves redesigning instruction and curricula around fundamental scientific ideas that serve as conceptual scaffolds students can use to build cohesive knowledge structures. In this study, we investigated how students use mass balance reasoning as a conceptual scaffold to gain a deeper understanding of how matter moves through biological systems. Our aim was to lay the groundwork for a mass balance learning progression in physiology. We drew on a general models framework from biology and a covariational reasoning framework from math education to interpret students' mass balance ideas. We used a constant comparative method to identify students' reasoning patterns from 73 interviews conducted with undergraduate biology students. We helped validate the reasoning patterns identified with >8000 written responses collected from students at multiple institutions. From our analyses, we identified two related progress variables that describe key elements of students' performances: the first describes how students identify and use matter flows in biology phenomena; the second characterizes how students use net rate-of-change to predict how matter accumulates in, or disperses from, a compartment. We also present a case study of how we used our emerging mass balance learning progression to inform instructional practices to support students' mass balance reasoning. Our progress variables describe one way students engage in three dimensional learning by showing how student performances associated with the practice of mathematical thinking reveal their understanding of the core concept of matter flows as governed by the crosscutting concept of matter conservation. Though our work is situated in physiology, it extends previous work in climate change education and is applicable to other scientific fields, such as physics, engineering, and geochemistry.  相似文献   
100.
This article examines how we use mobile telephony to maintain our physically and socially closest social circle. The analysis is based on traffic data gathered from Norway using approximately 24 million calls and texts made by private individuals. Previous research has shown that our temporal and spatial movement is highly predictable and that the majority of calls and text messages are sent to only four to six different persons. This article extends this research by examining both tie strength and the distance between the interlocutors in urban and rural settings. The findings show that even as information and communication technologies (ICTs) potentially put the world at our fingertips, the mobile phone is an instrument of a more limited geographical and social sphere. Approximately two-thirds of our calls/texts go to strong ties that are within a 25-km radius.  相似文献   
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