Because gender may not be the most pressing source of inequality in every situation, however, there have been calls to shift focus from “gender” to “diversity” mainstreaming, thus taking a wider approach to inequality (Siltanen 2006, p. 9213). High quality, readily accessible gender-disaggregated data supplies the foundation for both sound evidence-based policy making and gender monitoring and evaluation, and is integral to gender impact assessment. Conversely, the absence of differentiated data (Box 4.11) makes it very difficult to understand the impact of gender equality and mainstreaming strategies and efforts.