Ryan Nixon

This quasi-experimental study investigated how explicit instruction about multiple modes of representation (MMR) impacted grades 7 (n = 61) and 8 (n = 141) students learning and multimodal use on end-of-unit assessments. Half of each teachers (n = 3) students received an intervention consisting of explicit instruction on MMR in science discourse, in addition to regular science instruction enhanced by a focus on MMR; comparison groups of students received regular science instruction. Three ordinary least squares regression models used student demographic variables and whether or not students received the intervention to predict students (a) gain scores on end-of-unit tests, (b) voluntary use of embedded MMR on unit tests, and (c) retention of science knowledge as measured by a state end-of-level criterion- referenced assessment. Analyses showed that explicit instruction on MMR did not make a significant impact on student gain scores, the amount of embeddedness on unit tests, or end-of-level scores. However, Models 2 and 3 showed Hispanics and females used MMR more on end-of-unit tests than Whites or males, respectively, whether or not they received the intervention. Hispanics and females scored lower than Whites or males, respectively, on end-of-level, multiple-choice assessments. Implications for classroom teachers and educational researchers in relation to these underserved populations are discussed.

The results of international assessments such as the Trends in International Mathematics and Science Study (TIMSS) are often reported as rankings of nations. Focusing solely on national rank can result in invalid inferences about the relative quality of educational systems that can, in turn, lead to negative consequences for teachers and students. This study seeks an alternative data analysis method that allows for improved inferences about international performance on the TIMSS. In this study, four classroom teachers categorized a sample of TIMSS items by the cognitive domains of knowing and applying using the definitions provided by the TIMSS 2011 Assessment Frameworks. Items of different cognitive domains were analyzed separately. This disaggregation allowed for more valid inferences to be made about student performance. Results showed almost no significant difference between the performance of U.S. students and the students of five other nations. Additionally, no differences were observed in U.S. students performance on knowing items and applying items, although students from some sample nations performed significantly better on knowing items. These results suggest that policy makers, educators, and citizens should be cautious when interpreting the results of TIMSS rank tables.

Using structural equation modeling, we explored the relationship between practicing 5^th and 6^th grade elementary teachers subject matter knowledge (SMK) of the science topics they are responsible for teaching and other factors, including teaching experience (number of years teaching current grade level), science teaching self-efficacy, formal science-related professional development opportunities, college science coursework, and instructional time devoted to science. Results indicate that teaching experience and science teaching self-efficacy were predictive of participants science SMK; other factors only indirectly influenced science SMK through teachers science teaching self-efficacy. Potential reasons and implications are discussed.