This final editorial of 2017 describes a future vision of mathematics education research that blurs the boundaries of research and practice to address teachers’ problems.

In their Research Commentary, Kitchen and Berk (2016) argue that educational technology may focus only on skills for low-income students and students of color, further limiting their opportunities to learn mathematical reasoning, and thus pose a challenge to realizing standards-based reforms. Although the authors share the concern about equity and about funds wasted by inappropriate purchases of technology before planning based on research and the wisdom of expert practice, including inadequate professional development, they believe that Kitchen and Berk’s commentary contains several limitations that could be misconstrued and thus misdirect policy and practice.

The author investigates the influence of the dominant culture characterizing mathematics education—which she terms the culture of exclusion—on efforts to teach for equity. Analyzing a year of observations in an urban high school mathematics department, she found that this culture structured everyday instruction even for teachers who expressed a strong commitment to equity and who participated in ongoing equity-oriented professional development.

The authors describe the development and validation of 2 forms of the Geometry Assessments for Secondary Teachers (GAST), which were designed to assess teachers’ knowledge for teaching geometry. GAST assessment scores explained a statistically significant but small amount of the variance of student scores, demonstrating an effect that was greater than the number of years of teaching experience but smaller than the effect of having an advanced degree.

This study investigates 3 hypotheses about proof-based mathematics instruction: (a) that lectures include informal content (ways of thinking and reasoning about advanced mathematics that are not captured by formal symbolic statements), (b) that informal content is usually presented orally but not written on the board, and (c) that students do not record the informal content that is only stated orally but do if it is written on the board. The authors found that (a) informal content was common (with, on average, 32 instances per lecture), (b) most informal content was presented orally, and (c) typically students recorded written content while not recording oral content in their notes.

A book review of the 2016 book Tools and Mathematics: Instruments for Learning, by John Monaghan, Luc Trouche, and Jonathan M. Borwein.

Individuals who served as guest editors and reviewers for manuscripts submitted to JRME in 2016 are acknowledged.

A listing of articles, departments, and book reviews that appeared in 2017 across volume 48.