Fetal Substance Exposure and Cumulative Environmental Risk in an African American Cohort

Two models of vulnerability to socioenvironmental risk were examined in 337 African American children (M = 7.8 years) recruited to overrepresent prenatal alcohol or cocaine exposure: The cumulative risk model predicted synergistic effects from exposure to multiple risk factors, and the fetal patterning of disease model predicted that prenatal insult will increase vulnerability to environmental risk. Four or more risks emerged as a threshold for poorer cognitive and behavioral outcome among the non‐substance‐exposed children, whereas substance‐exposed children showed greater vulnerability to lower levels of environmental risk. Cumulative risk was associated with increased delinquent and internalizing behaviors only for the substance‐exposed group. Results support the cumulative risk model for non‐substance‐exposed children and increased vulnerability to environmental risk among the substance‐exposed group.     

Contextualizing instruction: Leveraging students' prior knowledge and experiences to foster understanding of middle school science

Contextualizing science instruction involves utilizing students' prior knowledge and everyday experiences as a catalyst for understanding challenging science concepts. This study of two middle school science classrooms examined how students utilized the contextualizing aspects of project‐based instruction and its relationship to their science learning. Observations of focus students' participation during instruction were described in terms of a contextualizing score for their use of the project features to support their learning. Pre/posttests were administered and students' final artifacts were collected and evaluated. The results of these assessments were compared with students' contextualizing scores, demonstrating a strong positive correlation between them. These findings provide evidence to support claims of contextualizing instruction as a means to facilitate student learning, and point toward future consideration of this instructional method in broader research studies and the design of science learning environments. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 79–100, 2008     

Degrees of Freedom

This article reviews several attempts to define degrees of freedom, and offers some simple explanations of how they are derived and why they are used in various contexts.     

Young adult outcomes of the Abecedarian and CARE early childhood educational interventions

Adult benefits for participants in Project CARE were compared with those of the Abecedarian Project, a closely related randomized study of early childhood educational intervention for children from low-income families who were at risk of developmental delays and school failure. CARE replicated Abecedarian's young adult treatment-related educational and vocational attainment gains. CARE data also supported the Abecedarian reduction in marijuana use. Treated individuals in both studies reported adopting a more active life style. The average age at birth of a first child, the number of children, and the proportion of teen parents were positively affected in the Abecedarian sample but not in CARE. Finding significant educational and vocational gains lasting into young adulthood in the CARE study reinforces Abecedarian young adult findings and strengthens the case for early childhood intervention for children from low-income families.     

Situating Data Science: Exploring How Relationships to Data Shape Learning

The emerging field of Data Science has had a large impact on science and society. This has led to over a decade of calls to establish a corresponding field of Data Science Education. There is still a need, however, to more deeply conceptualize what a field of Data Science Education might entail in terms of scope, responsibility, and execution. This special issue explores how one distinguishing feature of Data Science—its focus on data collected from social and environmental contexts within which learners often find themselves deeply embedded—suggests serious implications for learning and education. The learning sciences is uniquely positioned to investigate how such contextual embeddings impact learners’ engagement with data including conceptual, experiential, communal, racialized, spatial, and political dimensions. This special issue demonstrates the richly layered relationships learners build with data and reveals them to be not merely utilitarian mechanisms for learning about data, but a critical part of navigating data as social text and understanding Data Science as a discipline. Together, the contributions offer a vision of how the learning sciences can contribute to a more expansive, agentive and socially aware Data Science Education.     

Secondary school physics teachers' conceptions of scientific evidence: An exploratory case study

This article describes an exploratory case study of secondary school physics teachers' conceptions of scientific evidence. The nature of teachers' conceptions of evidence was derived from an analysis of data collected from 1 preservice and 2 in‐service teachers. Each teacher responded to a series of research prompts in multiple interviews and handwritten tasks. In these research prompts, the teachers thought aloud while designing experiments and critically evaluating student‐collected data as presented in hypothetical classroom scenarios. Spoken and written data were recorded. The data set was coded and analyzed using standard qualitative analysis techniques. Data from this study suggest that, while contemplating the reliability and validity of hypothetical student‐generated scientific evidence, the teachers frequently intertwined conceptions of evidence with subject matter concepts centrally relevant to the hypothetical investigation. Data also indicate that the relationship between subject matter knowledge and conceptions of evidence was more pronounced for some conceptions of evidence than for others. Results suggest that a fuller study is warranted. Suggestions for future research include exploring such relationships in other physics content areas as well as other scientific disciplines. Implications for science teacher education suggest that science and science methods courses should encourage preservice teachers to engage in original scientific research, as well as participate in peer review and critique. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 721–736, 2003     

Let’s Cross the Next One: Parental Scaffolding of Prospective Control Over Movement

This investigation examined parental scaffolding of children’s prospective control over decisions and actions during a joint perception-action task. Parents and their 6-, 8-, 10-, and 12-year-old children (N = 128) repeatedly crossed a virtual roadway together. Guidance and control shifted from the parent to the child with increases in child age. Parents more often chose the gap that was crossed and prospectively communicated the gap choice with younger than older children. Greater use of an anticipatory gap selection strategy by parents predicted more precise timing of entry into the gap by children. This work suggests that social interaction may serve as an important experiential mechanism for the development of prospective control over decisions and actions in the perception–action domain.     

Parameter Estimation Accuracy of the Effort-Moderated Item Response Theory Model Under Multiple Assumption Violations

As low-stakes testing contexts increase, low test-taking effort may serve as a serious validity threat. One common solution to this problem is to identify noneffortful responses and treat them as missing during parameter estimation via the effort-moderated item response theory (EM-IRT) model. Although this model has been shown to outperform traditional IRT models (e.g., two-parameter logistic [2PL]) in parameter estimation under simulated conditions, prior research has failed to examine its performance under violations to the model’s assumptions. Therefore, the objective of this simulation study was to examine item and mean ability parameter recovery when violating the assumptions that noneffortful responding occurs randomly (Assumption 1) and is unrelated to the underlying ability of examinees (Assumption 2). Results demonstrated that, across conditions, the EM-IRT model provided robust item parameter estimates to violations of Assumption 1. However, bias values greater than 0.20 SDs were observed for the EM-IRT model when violating Assumption 2; nonetheless, these values were still lower than the 2PL model. In terms of mean ability estimates, model results indicated equal performance between the EM-IRT and 2PL models across conditions. Across both models, mean ability estimates were found to be biased by more than 0.25 SDs when violating Assumption 2. However, our accompanying empirical study suggested that this biasing occurred under extreme conditions that may not be present in some operational settings. Overall, these results suggest that the EM-IRT model provides superior item and equal mean ability parameter estimates in the presence of model violations under realistic conditions when compared with the 2PL model.     

Meta‐analysis and mega‐analysis: A simple introduction

Statistical methods are increasingly being used to integrate findings from the ever‐expanding universe of empirical research. Meta‐analysis encompasses various techniques for synthesizing summary statistics, and mega‐analysis pools raw data across studies. This paper offers an introduction to meta‐analysis and mega‐analysis that complements the study of analysis of variance (ANOVA). After a brief conceptual discussion, we provide simple numerical examples.     

Collaborative bibliography

A bibliography is traditionally characterized by the judgments, bounded by explicit selection criteria, made by a single compiler. Because these criteria concern the attributes ascribed to a work and the needs of readers, bibliographic work is largely conceptual even across technological eras and domains. Yet, the development of networked information services, made possible by WWW infrastructure, has enabled very large numbers of people to discover, organize, and publish information, including bibliographies. Indeed, bibliographies, or at least bibliography-like artifacts, are a common genre of website, often published by people without specialized skills in information organization who follow non-rigorous selection procedures. Nevertheless, even if the items from these lists are poorly selected and described, this publishing activity is fundamentally important because it structures information locally, creating a patchy network of secondary access points. In turn, these access points enable information discovery, the formation and development of communities of interest, the estimation of document relevance by search engines, and so on. In sum, this activity, and the enabling technical infrastructure, invites bibliographies to take on new interactive possibilities. The aim of this article is to extend the traditional view of bibliography to encompass collaborative possibilities for wide, or narrow, participation in the shaping of bibliographies and the selection of items. This is done by examining the nature of bibliography on the Web, by proposing a conceptual model that opens bibliography to participatory practices, and by discussing a case study where a team sought to develop a bibliography of electronic resources. This examination reveals splendid opportunities for expanding the notion of bibliography with participatory policies while remaining true to its ancient roots.