For the past several years, scores on the Massachusetts Comprehensive Assessment System (MCAS) tests have improved—in some cases substantially. But because of the way progress is measured, many schools still find themselves on the federal watch list due to disparities in performance among subgroups: white, black, Hispanic, Asian, and Native American students, as well as low-income, special education, and limited English students.

Under the No Child Left Behind Act, school progress is measured by overall improvement in both English and Math, and reducing the gap among subgroups in both English and Math. A school that fails to make progress in any one of these areas is flagged as needing improvement.

For several of the past six years, Cambridge’s overall scores in both English and math have risen. But because high-scoring groups (Asian students) have seen greater progress than low-scoring ones (special education students), schools appear the federal watch list despite the general gains in achievement.

Recently, the school district has made some progress in reducing disparities between the subgroups, with poorer students and racial minorities improving their performance relative to higher-achieving groups.

In 2006, Cambridge Rindge and Latin School improved subgroup performance for the first time since 2003, the first year the achievement gap was monitored. If the school closes the gaps further this year, it will be removed from the federal watch list altogether.

Members of the School Committee advocate different approaches to closing achievement gap.

Former committee member and candidate Marc C. McGovern argues that in order to make a significant dent, the school district has to expand access to early childhood education and address a host of other factors—like health care, nutrition, and parent involvement.

Others, like committee members Patricia M. Nolan ’80 and Luc D. Schuster, have argued that schools perform better if principals are empowered, and they have sought to put millions of dollars into the hands of principals to be used as discretionary funds.

And Richard Harding, the only racial minority on the School Committee, has long made Cambridge’s achievement gap a significant part of his platform, and is running on his record of expanding access to summer school for struggling students and tightening certification standards for teachers.