Miyamoto, Y. R., Coleman, C., Williams, J. J., Whitehill, J., Nesterko, S., & Reich, J. (2015). Beyond Time-on-Task: The Relationship Between Spaced Study and Certification in MOOCs. Journal of Learning Analytics, 2(2), 47-69. https://doi.org/10.18608/jla.2015.22.5