The case for inquiry-based approaches remains strong, even in light of increasing pressure on teachers to use direct teaching to 'cover' content to prepare students for high-stakes tests. Although the implementation of inquiry may not yet be at an ideal level, it has been shown that inquiry-based instruction is not at odds with teaching for achievement on standardized tests. Blanchard, Southerland, Osborne, Sampson, Annetta, & Granger (2010) found students whose teachers used Level 2 inquiry approaches outperformed students who received verification (Level 0) laboratory instruction. This is consistent with findings from Wilson, Taylor, Kowalski, and Taylor (2010) who found that students taught with inquiry materials and approaches (BSCS 5E instructional model) achieved significantly higher achievement (knowledge, reasoning, and argumentation) than students receiving "commonplace instruction" from the same teacher. Moreover, Wilson and coworkers' found that the inquiry approach did not produce an achievement gap by race as did the commonplace science instruction.
The causal connection between teacher professional development and desirable student outcomes has been strengthened by experimental and quasi-experimental research conducted over the past 30 or so years. A report by Yoon, Duncan, Lee, Scarloss, & Shapley (2007) identified over 1,300 studies which potentially address how teacher PD affects student achievement. However, only 9 of these studies met the What Works Clearinghouse standards for evidence. Thus TI answers both the call for long-term, content-oriented PD (Smith, Desimone, Zeidner, Dunn, Bhatt, & Rumyantseva, 2007) as well as the need for rigorous research on teacher PD and its student effects, which has been noted in a number of recent and key policy papers on PD (Desimone, 2009; Penuel, Fishman, Yamaguchi, & Gallager, 2007; Wayne, Yoon, Zhu, Cronen & Garet, 2008).
Although the last decade of research has not markedly shaped what are considered the "best practices" in PD (Wayne et. al, 2008), recent studies have demonstrated the effects when these practices are implemented with fidelity. Khourey-Bowers and Fenk (2010) found that constructivist PD enhanced chemistry PCK in middle and high school teachers. Moreover, findings from a recent study by Lui, Lee, and Linn (2010) found students' understanding of knowledge integration (Linn, 2006) was predicted by teachers' use of inquiry teaching strategies, PD, and collegial support. The results of these investigations and other studies like them are promising; however, they rely primarily on teacher self-report data. Our study offers observational data (using the RTOP) as a means of evaluating teacher practice and knowledge of inquiry teaching approaches over time. Findings from early TI cohorts demonstrate the utility of the RTOP, how it is effective for tracking instructional practice, and how instruction improves as a result of TI (Yezierski & Herrington, 2011).
A construct known as pedagogical discontentment (Southerland, Sowell, Blanchard, & Granger, 2010) sheds new light on TI pilot findings. We observed a decline in teacher self-efficacy as measured by the Science Teaching Efficacy Beliefs Instrument (STEBI) and the TSI Instrument (Teaching Science with Inquiry). The qualitative interview data and RTOP scores demonstrated that, as teachers became more aware of gaps between proven practices and their practices, they became increasingly critical of their teaching (Herrington, Yezierski, Luxford, & Luxford, 2011). Southerland and coworkers' work on pedagogical discontent illuminates our findings and provides a promising framework for understanding the causes and nature of teacher change through intensive, content-based, and coherent inquiry-focused PD.
Although the features of effective PD have not markedly changed since the TI model was developed in 2003, work has been done to better characterize specific PD design and delivery elements. Based on a review of over 50 science and math projects funded through state Improving Teacher Quality Grants, Park Rogers, Abell, Marra, Arbaugh, Hutchins, and Cole (2009) generated and characterized a total of five PD design/delivery "orientations." Their work provides a succinct and concrete way to describe PD while recognizing how knowledge and beliefs about PD held by PD designers and facilitators account for differences in PD orientations. An examination of their five orientations (Activity-driven, Content-driven, Pedagogy-driven, Curriculum materials-driven, and Needs-driven) demonstrates the multidimensionality of PD experiences in TI. Even the sum of the orientations does not adequately characterize the varied and long-term experiences outlined for the delivery of the TI derivatives. In particular, the RET and teacher action research components of TI are not portrayed in the orientations generated by their study. Park Rogers' and coworkers' findings therefore endorse the novelty of TI and its derivatives. The literature not only shows TI's uniqueness but further supports its core experiences. Gerard, Spitulnick, and Linn (2009) revealed how teachers using evidence from student work to customize curriculum leads to improved teacher and student learning. This strongly supports the curriculum adaptation and action research components of TI. Like Gerard, et. al found with the nine teachers they studied, questioning, inquiry investigations, and revisions to teaching strategies are common customizations TI teachers carry out in the final year of the program.