Although academic writing is a complex interplay of comprehending and producing text the aspect of collecting information from source texts is hardly addressed in writing research. This study examined the impact of instructions supporting the collection process on writing quality, as well as the role of prior motivation and computer experience. University freshman had to compose a text by using sources with contradictory positions. Students of tire experimental group received computer-based instructions on how to efficiently reduce information from source texts. They were compared to a control group without instructions. Collection quality was measured in terms of information units in the excerpt, while writing quality in the final text product was rated in terms of accuracy and coverage of evidence. The results show mat the experimental group collected more information, but produced text products containing less relevant information man the control group. Unexpectedly, motivation did not influence writing performance while computer experience significantly affected writing quality in the control group.