The vibrational mode structure of a golf ball

In this paper, we report the discrete frequencies at which golf balls can vibrate, the mode patterns of these vibrations and how these modes can be excited. There are two broad classes of modes: those that radiate sound waves and those that do not. Both silent and acoustic modes are excited by tangential (i.e. spin-producing) impact forces; only acoustic modes are excited by radial impact forces. Exact analytical results for a homogeneous ball core are compared with finite element numerical results for both a core and a model two-piece ball. Correspondences are readily established for the important low-frequency modes, and the good agreement suggests the validity of these results for real golf balls. The results potentially provide the basis for a rapid, simple and non-destructive method of measuring the effective high-frequency elastic shear modulae of balls (and ball cores) as well as a method for 'tuning' the performance of balls for specific clubs. Some of these aspects are explored further in our companion paper in this issue.     

A Second-Order Longitudinal Model for Binary Outcomes: Item Response Theory Versus Structural Equation Modeling

Measuring academic growth, or change in aptitude, relies on longitudinal data collected across multiple measurements. The National Educational Longitudinal Study (NELS:88) is among the earliest, large-scale, educational surveys tracking students’ performance on cognitive batteries over 3 years. Notable features of the NELS:88 data set, and of almost all repeated measures educational assessments, are (a) the outcome variables are binary or at least categorical in nature; and (b) a set of different items is given at each measurement occasion with a few anchor items to fix the measurement scale. This study focuses on the challenges related to specifying and fitting a second-order longitudinal model for binary outcomes, within both the item response theory and structural equation modeling frameworks. The distinctions between and commonalities shared between these two frameworks are discussed. A real data analysis using the NELS:88 data set is presented for illustration purposes.     

Early childhood teachers' views of nature of science: The influence of intellectual levels,cultural values,and explicit reflective teaching

This study tracked the influence of explicit reflective instructional methods on cultural values, ethical and intellectual development, and the relationship of these with preservice teachers' views of nature of science (NOS). The researchers used the Views of Nature of Science Form B (VNOS B) to describe NOS views, the Learning Context Questionnaire (LCQ) to classify preservice teachers' ethical and intellectual positions using Perry's scheme, and the Schwartz Values Inventory (SVI) to measure preservice teachers' cultural values. The interventions took place in two concurrent courses: a science methods course, and a foundations of early childhood course. The science methods course explicitly emphasized NOS throughout the semester, and the foundations of early childhood course reinforced these ideas through cultural activities that stressed empirical evidence. Analysis of data showed relationships between preservice teachers' Perry positions and responses on the VNOS B with those at higher positions exhibiting more informed NOS views. Relationships between preservice teachers' NOS views and their cultural values were identified, such as those at the dualism position holding achievement more highly for scientists than those at other Perry positions. The values preservice teachers held personally were different from those they held as important for scientists. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 748–770, 2008     

Trainee teachers in unpaid teaching posts: volunteering,risk and vulnerability

This paper explores the experiences and perceptions of a little-known category of in-service trainee teachers in the Further Education (FE) and Skills sector in England: those who meet the practical teaching requirements of their course mainly through unpaid teaching as ‘volunteers’. The paper reports findings from mixed-methods research which used surveys, interviews and focus groups involving trainee teachers within a large FE–HE partnership. Themes relating to motivations to volunteer, the development of teacher identity within marginal roles, and the risks associated with unpaid teaching are discussed. For increasing numbers of trainees, unpaid teaching provides an opportunity for career entry. However, the quality of teaching experience gained is mixed, with some trainees receiving high levels of support, whilst others experience marginalisation and limitations on their developing teacher identities. The paper highlights the specific challenges to professionalism posed by unpaid teaching within the FE and Skills sector, and relates these challenges to a broader context of insecurity and risk. As work experience becomes an increasingly valuable commodity, this paper illustrates the pressures individuals face as they exchange payment and security for the opportunities volunteering provides.     

Theory of mind and social interest in zero-acquaintance play situations

Many studies have examined associations between children's theory of mind and social behavior with familiar peers, but to date none have examined how theory of mind might relate to behavior toward unfamiliar peers in a play setting. Forty-four 4-year-olds (21 girls, 23 boys) participated in standard theory-of-mind tasks and in a play session with 3 or 4 other children who were unfamiliar. Children were also tested on general vocabulary ability. No relations were found between theory of mind and social engagement. However, positive associations were found between theory of mind and time spent observing, but not interacting with, other children. Possible explanations of the links between theory of mind, temperament, and social interest are considered.     

Desiring silence: Gender,race and pedagogy in education

In my work with white teachers, predominantly female, I assert that ‘desire’ is functioning to produce silent discourses that serve to perpetuate a continuation of white privilege. Based on a qualitative research study exploring the nature of silences in teacher education classrooms, this paper seeks to explore how desire is functioning to produce such silences and how they can be productively understood. Using the concept of desire as presented by Deleuze, this paper engages a notion of desire that is not spawned from lack but a desire that is generative and seeking, resulting in the production of privilege, power and voice.     

Face-to-face versus computer-mediated discussion of teaching cases: Impacts on preservice teachers’ engagement, critical analyses, and self-efficacy

Two frequently-used discussion protocols were investigated as part of a program to implement teaching cases in undergraduate educational psychology classes designed for preservice teachers. One protocol involved synchronous face-to-face (FTF) discussion of teaching cases, which occurred in class after students had individually completed written case analyses as homework outside of class. The other was asynchronous computer-mediated (CM) discussion taking place outside of class, simultaneous to students’ completion of their written case analyses. Six class offerings of an undergraduate child development course taught by two instructors (three classes by each instructor) were randomly assigned within instructor in a quasi-experimental design to one of the three discussion conditions: FTF, CM, or no discussion of the cases across the semester. Findings indicated that both CM and FTF discussion conditions were associated with positive outcomes relative to the control condition. Both CM and FTF discussion related to higher cognitive–affective engagement with the cases than the control condition; and the CM discussion condition was associated with higher cognitive–affective engagement than FTF discussion. In contrast, FTF discussion, but not CM discussion, was associated with higher-than-control-condition case analysis ability at the end of the semester. Potential explanations for these findings and directions for future research are discussed.     

‘The constant rejections hurt’: Skills and personal attributes needed to successfully complete a thesis by publication

The thesis by publication (TBP) is an increasingly popular approach to doctoral education that sees candidates publishing their research during their candidature, and including these outputs in their final thesis submission. Responsive to the realities of modern academia, a TBP provides doctoral candidates with opportunities to engage in the scholarly publication process, and to build their research portfolio. As the TBP gains further traction in many fields and countries, there is a need to better understand the skills and attributes needed to complete a TBP successfully. This paper draws on the views of 246 recent doctoral graduates of Australian universities to identify the skills and attributes they felt supported their success. Their responses have implications for the development and refinement of institutional policies and programs that are sensitive to the needs and experiences of doctoral candidates seeking to publish during candidature and create a TBP. As editors, peer‐reviewers, and publishers see a growing influx of papers sole‐ or co‐authored by doctoral candidates in response to the trend toward TBP, they may find themselves involved in supporting students to develop the skills and attributes needed to successfully publish during candidature.     

Using digital images of the zebra finch song system as a tool to teach organizational effects of steroid hormones: a free downloadable module

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the ease of quantification and experimental manipulation, the zebra finch song system has great potential for use in undergraduate labs. Unfortunately, the underlying costs prohibit use of this system in undergraduate labs. Further, the time required to perform a developmental study renders such undertakings unrealistic within a single academic term. We have overcome these barriers by creating digital tools, including an image library of song nuclei from zebra finch brains. Students using this library replicate and extend a published experiment examining the dose of estradiol required to masculinize the female zebra finch brain. We have used this library for several terms, and students not only obtain significant experimental results but also make gains in understanding content, experimental controls, and inferential statistics (analysis of variance and post hoc tests). We have provided free access to these digital tools at the following website: http://mdcune.psych.ucla.edu/modules/birdsong.