The implementation of scientific inquiry in the high school classroom has proven to be not only relevant and exploratory, but challenging and engaging as well. This style of curriculum design has been recognized as a primary means of achieving the goals and objectives set by the National Resource Council (NRC, 1996). While much research has shown that science inquiry helps students to gain understanding of content knowledge, little research has been conducted to assess gains in higher order thinking skills, specifically those related to data analysis (Anderson, 2002; Germann and Aram, 1996; Hofstein, Navon, Kipnis, and Mamlok-Naaman, 2005; Miner, Levy, and Century, 2009; Windschitl, Thompson, and Braaten, 2008; Zohar and Dori, 2003). Through a better understanding of the scientific inquiry process as well as insights into students' struggles with data analysis, we can better understand how to effectively implement strategies in the classroom that encourage the higher order thinking skill of data analysis. This mixed methods, multiple-case study investigated teacher practice in eight high school science inquiry units in the Portland, Oregon metropolitan area and the data analyses that students produced in their accompanying work samples. The results of this study indicate that students struggle to produce proficient analysis and interpretations of data. The areas of student struggle were in the areas that required higher order thinking: analyzing results, drawing conclusions, and communicating results. Furthermore, this research discusses areas of data analysis instruction that may benefit from professional development opportunities.

The Framework for K-12 Science Education, the foundation for the Next Generation Science Standards, identifies scientific explanation as one of the eight practices "essential for learning science." In order to design professional development to help teachers implement these new standards, we need to assess students' current skill level in explanation construction, characterize current teacher practice surrounding it, and identify best practices for supporting students in explanation construction. This multiple-case study investigated teacher practice in eight high school science inquiry units in the Portland metro area and the scientific explanations the students produced in their work samples. Teacher Instructional Portfolios (TIPs) were analyzed with a TIP rubric based on best practices in teaching science inquiry and a qualitative coding scheme. Written scientific explanations were analyzed with an explanation rubric and qualitative codes. Relationships between instructional practices and explanation quality were examined. The study found that students struggle to produce high quality explanations. They have the most difficulty including adequate reasoning with science content. Also, teachers need to be familiar with the components of explanation and use a variety of pedagogical techniques to support students' explanation construction. Finally, the topic of the science inquiry activity should be strongly connected to the content in the unit, and students need a firm grasp of the scientific theory or model on which their research questions are based to adequately explain their inquiry results.