We report an empirical comparison of the effectiveness of two theoretically motivated computer-assisted reading interventions (CARI) based on the Finnish GraphoGame CARI: English GraphoGame Rime (GG Rime) and English GraphoGame Phoneme (GG Phoneme). Participants were 6-7-year-old students who had been identified by their teachers as being relatively poor at reading. The students were divided into three groups. Two of the groups played one of the games as a supplement to normal classroom literacy instruction for five sessions per week for a period of 12 weeks. The third group formed an untreated control. Both games led to gains in reading, spelling, and phonological skills in comparison with the untreated control group. The two interventions also had some differential effects. The intervention gains were maintained at a four-month follow-up. (Contains 4 tables, 2 figures, and 1 note.)