As computers are steadily gaining entry to places of learning, people seek to use them to the fullest. Not only can they be used as an instrument toward gaining knowledge and experience, they can also take an active role in this. This is where EssayCritic comes in. EssayCritic is a critiquing system that takes on the role of a tutor, guiding the user as he writes an essay in English as a foreign language.In my thesis, I seek to find out how the usage of this system influences, and is influenced by, collaborative learning in a classroom setting. This mainly qualitative study rests on a theoretical background of a sociocultural understanding of the world, established by pioneers like Soviet researcher Vygotsky, revived and refined by Wood and others from the mid 1970s and onwards.The empirical data is collected on site at an upper secondary school in Norway, involving a team of researchers and school teachers. Three groups of pupils entered the experiment, split into a treatment group and a control group. The experiment took place at this school within normal school hours, and a myriad of data was collected by various means. Qualitative data was collected by conducting videotaping the experiment, as well as interviews and an evaluation session. Also, artefacts in the form of essays were gathered. Quantitative data, here only used for illustrational purposes, have been collected via a questionnaire and derived from coded qualitative data.As earlier research was done on the use of EssayCritic, the scope was moved away from a technical perspective within an individual setting to a collaborative setting. I focus on how EssayCritic is used with peer efforts within a collaborative setting. Also, I investigate in how far and what role scaffolding takes within this process, and which attitude the users develop towards using EssayCritic.My findings show strengths and weaknesses of EssayCritic according to all involved parties, and to what extent the aforementioned theory base comes to life within this very real world of learning within a school setting.