The Impact of Ignoring Time Series Processes in Linear Growth Mixture Modeling     

Namwook Koo  Walter L. Leite 《Structural equation modeling》2013,20(2):210-224

Growth mixture modeling (GMM) is a useful statistical method for longitudinal studies because it includes features of both latent growth modeling (LGM) and finite mixture modeling. This Monte Carlo simulation study explored the impact of ignoring 3 types of time series processes (i.e., AR(1), MA(1), and ARMA(1,1)) in GMM and manipulated the separation of the latent classes, the strength of the time series process, and whether the errors conformed to the time series process in 1 or 2 latent classes. The results showed that omitting time series processes resulted in more serious bias in parameter estimation as the distance between classes increased. However, when the class distances were small, ignoring time series processes contributed to the selection of the correct number of classes. When the GMM models correctly specified the time series process, only models with an AR(1) time series process produced unbiased parameter estimates in most conditions. It was also found that among design factors manipulated, the distance between classes prominently affected the identification of the number of classes and parameter estimation.  相似文献   

A Holistic Course on the Environment     

Walter W. Haines 《College Teaching》2013,61(3):114-117

Abstract

This article describes how anecdotal teaching can relate classroom material more effectively than lecture presentations. Personalizing the lesson engages students and increases retention.  相似文献   

Hofstra's New College: The Student View     

Walter T. Schoen Jr. 《College Teaching》2013,61(4):210-213

The authors examined student reactions to an activity in computer science, psychology, women's studies, and education courses. The reciprocal interview involves the instructor gathering information about the students, followed by students collectively asking questions of the instructor. The interview aims to make students more comfortable in interactions with the instructor by soliciting student input. Student responses indicated they enjoyed the activity and recommend faculty use it in various courses. Participants also reported the interview process helped create a more comfortable classroom environment and helped clarify instructors' expectations of students.  相似文献   

Teacher     

Walter W. Stevens 《College Teaching》2013,61(2)

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Teacher Education Laboratory Experiences     

Walter A. Mercer 《College Teaching》2013,61(2):110-111

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Graduate Work in Literary Criticism     

Walter J. De Mordaunt 《College Teaching》2013,61(4):175-176

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Muscle Fiber Type Composition and Knee Extension Isometric Strength Fatigue Patterns in Power- and Endurance-Trained Males     

Walter Kroll  Priscilla M. Clarkson  Gary Kamen  Jean Lambert 《Research quarterly for exercise and sport》2013,84(2):323-333

Abstract

Muscle fiber type composition in the vastus lateralis and knee extension isometric strength fatigue patterns were assessed in eight endurance-trained and eight power-trained males. Two different 25-trial isometric contraction exercise regimens were administered: a 10-second contraction, 5-second intertrial rest condition designed to induce a fast rate of fatigue and a 10-second contraction, 20-second intertrial rest condition designed to induce a slower rate of fatigue. The power group fatigued almost four times faster than the endurance group in the 10:5 exercise condition. In the 10:20 exercise condition, the endurance group showed no fatigue pattern while the power group had a significant strength decrement of 32%. In both exercise conditions, the power group exhibited more complex fatigue patterns in terms of statistically significant trend components. Maximum isometric strength correlated positively with slow twitch (ST) percent number in power (r = .80) and endurance (r = .48) groups, but negatively with linear trend coefficients in endurance (r = -.62) and power (r = -.80) groups. Maximum isometric strength also correlated higher with fatigue curve trend coefficients than did muscle fiber type composition. Thus, a faster rate of fatigue was associated with higher maximum isometric strength and with higher ST percent number and area. Since maximum isometric strength correlated with body weight (r = .86 for groups combined), both maximum isometric strength and muscle mass appear to be more important determinants of knee extension isometric strength fatigue patterns than muscle fiber type composition.  相似文献   

Linguistic Invention and Semantic Warrant Production: Elementary Teachers’ Interpretation of Graphs     

Janet Walter  Christine Johnson 《International Journal of Science and Mathematics Education》2007,5(4):705-727

In this qualitative study of mathematical discourse between elementary teachers, we examined linguistic invention and semantic warrant production as participants made successive attempts to communicate mathematical ideas. Linguistic invention is a creative practice of describing mathematics in terms of personal experience. We introduce semantic warrant production, which emerged as part of our analysis of substantial arguments produced by teachers learning mathematics. Participants engaged in linguistic invention and semantic warrant production to convince themselves and others of the validity of their mathematical inferences about a graph of rate of change versus time. Personal experiences that are taken-as-shared in a learning community can support accurate mathematical inference if connections between conventional language, common experiences, and mathematical representations are made explicit by learners.  相似文献   

Relative returns to human and physical capital in the U.S. and efficient investment strategies   总被引：1，自引：0，他引：1  

Walter W. Mcmahon 《Economics of Education Review》1991,10(4)

This paper presents new estimates of the social rates of return to a high school and to a 4-year college education for males and females in the U.S. for each year from 1967 to 1988 based on microeconomic data from U.S. Census Bureau surveys. These are compared with the real rates of return to investment in plant and equipment and in housing since 1947. Results reveal drastic declines in returns to a junior high school education for those who leave (from 21 to 7%), steady rates of return to a high school education averaging 12%, and real rates of return to the college level rising gently to 12–14% levels in the late 80s, with a dip in the mid 70s. Rates of return to housing, including capital gains, were only 5% in this period, compared with 15% for plant and equipment investment.  相似文献   

Engaging Pre-Service Teachers in Multinational, Multi-Campus Scientific and Mathematical Inquiry     

Jennifer Anne Wilhelm  Walter S. Smith  Kendra L. Walters  Sonya E. Sherrod  Judith Mulholland 《International Journal of Science and Mathematics Education》2008,6(1):131-162

Pre-service teachers from Texas and Indiana in the United States and from Queensland, Australia, observed the Moon for a semester and compared and contrasted their findings in asynchronous Internet discussion groups. The 188 pre-service teachers were required to conduct inquiry investigations for their methods coursework which included an initial Moon observation assignment, an Internet Moon discussion, and a final project. The Moon context was chosen for its motivating capability, its inherent interdisciplinary makeup, its inclusion in the National Science Education Standards, and its ability to be viewed worldwide. This study was of a mixed method research design and involved pre-service teachers’ journals, summative reflections, Internet discussions, final projects, and the Lunar Phases Concept Inventory (LPCI). Analysis of the qualitative data was conducted through the exploration of patterns and themes that illustrated pre-service teachers’ conceptual development, and the LPCI was administered as a pre/post assessment. We found that our project led to increased knowledge concerning the mathematics and science involved with understanding the Moon and its phases. We also found that it was beneficial to have Internet discussions with pre-service teachers from around the world, but it was not without its problems (e.g., coordinating schedules and lack of participation by some participants). We discovered that pre-service teachers’ exposure to the new uses of technology for teaching and learning did not necessarily translate to their planning to adopt similar techniques in their own classrooms.  相似文献