"Fast Feedback" is a feedback system for primary student writing. Developed in line with a Writer(s)-Within-Community model, and empirical research in the fields of writing instruction, feedback and self-regulation, this system uses individualized goals and focused feedback in the expectation that it will accelerate student progress. In 2015 nine teachers were asked to trial Fast Feedback, in seven classrooms, across three Wellington schools. Achievement data were collected for 136 student participants, and compared with equivalent data from students at a control school. A student survey and teacher interviews were also used. Data analysis revealed that the treatment group made significantly more progress than the control group (ES 0.5). It also revealed variability across classrooms. Data analysis suggests that process-oriented goals were most effective, and that the addressing of transcription skills was critical. Teachers observed that Fast Feedback was motivating for students, and encouraged student independence.