As students' problem-solving processes in writing are rarely observed in face-to-face instruction, they have few opportunities to participate collaboratively in peer review to improve their texts. This study reports the design of a reciprocal peer review system for students to observe and learn from each other when writing. A sample of 95 undergraduate students was recruited to construct texts with the support of web-based reciprocal peer review in the processes of modelling, coaching, scaffolding, articulation, reflection and exploration. The results of the study revealed that these six processes helped students externalise and visualise their internal writing processes so that they could observe and learn from peers in writing as well as support peers in making text revisions. During their extensive and reciprocal interactions with various peers, students addressed mutual concerns in each other's text revisions. They constructed collaborative language knowledge for text improvement as local revisions (grammatical corrections) and global revisions (corrections on the development, organization or style of a text) were made in their final texts. The students' perceptions towards text improvement in this web-based peer review of modelling, coaching, scaffolding, articulation, reflection and exploration are also discussed in this study.