Shon Holland found CK-12 Foundation:

• Moderately improves attainment“The interactive pieces that directly support what students have just read.”
• Significantly builds student knowledge“They see a direct connection between the text, videos, and simulations to the real world.”
• Moderately improves teaching efficiency and productivity“There aren’t 100 different sites to visit - it’s all self contained”
• Significantly reduces teacher workload“Consistent layout, simple directions allow us to answer questions based on content and not on “where to find things””
• Significantly saves school money“Ck12 is free which allowed us to test it with no worry about “waisting money””