1. Nearly 150 Marginal Classroom Gains: https://lookoutforlearning.wordpress.com/2012/10/28/nearly-150-classroom-marginal-gains/
2. Error Seeking Classroom – a marginal learning gain from Zoe Elder (@fullonlearning): https://lookoutforlearning.wordpress.com/2012/12/11/marginal-learning-gains-an-error-seeking-classroom-by-zoe-elder/