Seattle's High Leverage Math teaching practices .... Lacking empirical evidence

You can find these: High Leverage math teaching practices here:
http://www.seattleschools.org/area/math/highlevprac.pdf

which Seattle plans for developing models for effective mathematics teaching through the use of High Leverage teaching practices and differentiation activities.

The problem here is again the lack of Empirical Evidence.
NMAP informs us that there is no reason to believe Seattle's "high leverage practices" will bring about improved academic gains.

Once again the SPS avoids teacher math content preparation in favor of more unproven pedagogical professional development.

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My problem with Seattle's differentiated activities can be found here:
http://mathunderground.blogspot.com/2009/02/what-is-my-problem-with-differentiated.html