This predominantly qualitative case study has been concerned with the use of a student essay critiquing system, named EssayCritic, in a collaborative setting with 26 students aged 16-17, at a Norwegian high school. It was done in close co-operation between InterMedia at the University of Oslo, Norway and Hong Kong Baptist University, Hong Kong. The goal has been to study how EssayCritic can help students writing essays in general, and the effect of collaboration in pairs, particularly. EssayCritic uses Latent Semantic Analysis, LSA, to compute feedback (critique) by comparing the students’ essays toward model essays collected and prepared by teachers or domain experts. All the students found the system useful in the role of providing critique, whereas the praising part was slightly less appreciated. The suggested sub themes were especially beneficial for the low-achieving students because it had the effect of stimulating those who experienced writing block. For all the students organization of the essay was underprioritized, even if this was stressed prior to the writing. The focus group organized their work in two different roles, “driver and navigator,” which can be classified as collaboration pattern, and the majority of the students were positive towards working in pairs. Feedback from the students about collaboration frequently included terms like stimulating “different ideas” and “discussion”.In sum, EssayCritic provided a valuable feedback for the students to reflect upon their essay and to give them suggestions for further writing. The system affords collaboration and was a positive element for the students when they wrote their essays. It seems like EssayCritic is especially useful for low-achieving students, but also high-achieving students seems to appreciate the use of EssayCritic, despite the fact that they also were critical to its use (believed it hindered individual creativity).