Issue 4 of JRME is out, and it contains lots of interesting articles:

• RESEARCH COMMENTARY: On “Gap Gazing” in Mathematics Education: The Need for Gaps Analyses, by Sarah Theule Lubienski
• RESEARCH COMMENTARY: A “Gap-Gazing” Fetish in Mathematics Education? Problematizing Research on the Achievement Gap, by Rochelle Gutiérrez
• RESEARCH COMMENTARY: Bridging the Gaps in Perspectives on Equity in Mathematics Education, by Sarah Theule Lubienski and Rochelle Gutiérrez
• Unpacking Pedagogical Content Knowledge: Conceptualizing and Measuring Teachers’ Topic-Specific Knowledge of Students, by Heather C. Hill, Deborah Loewenberg Ball and Stephen G. Schilling
• Josh’s Operational Conjectures: Abductions of a Splitting Operation and the Construction of New Fractional Schemes, by Anderson Norton
• How Mathematicians Determine if an Argument Is a Valid Proof, by Keith Weber