We built on two cognitive and three motivational theoretical constructs to create a combined intervention aiming to improve course achievement and retention in STEM for first-year ("gateway") biology students. Participants were 350 students in one of 8 conditions or a no-treatment control group. Messages supporting cognition and motivation were provided via a Blackboard site, with participation rates of 63-83%. Five of 8 conditions improved course grades over BAU, d = 0.46 - 0.69. Combinations of cognitive and motivational supports are better than either alone.