Lane-Fall, M.B., Curran, G.M., & Beidas, R.S. (2019). Scoping implementation science for the beginner: locating yourself on the “subway line” of translational research. BMC Medical Research Methodology, 19(133). doi:10.1186/s12874-019-0783-z
"In this paper, three implementation scientists share a heuristic tool to help investigators determine where their research questions fall in the translational research continuum. They use a “subway model” that envisions a journey to implementation research with stops along the way at efficacy and effectiveness research."