A formative assessment task was developed to improve the scientific report writing skills of university students. Students undertaking this task typically possessed varying levels of scientific literacy and were drawn from a cohort of mixed abilities. The assessment task involved the construction of a scientific report that included feedback from instructor to students before final submission of the assessment piece. After initial submission of a scientific report, the instructor developed a cohort-specific marking scheme based on the deficiencies that were evident within the class group. Using a mixture of peer and self-review against specific criteria, the students were required to resubmit an amended report. This resulted in elevated marks compared with those that would have been obtained after first submission, thus rewarding the student for the application of feedback. This technique proved to be efficient for both parties and also resulted in improvement of skills of the entire student population, regardless of the ability of the student prior to the assessment task. Using this methodology, students of varying aptitudes were able to measure their own skill improvement against tangible criteria, and enjoy a degree of learning success independent of the ranking within their group.