This paper evaluates the use of peer and self-assessments as part of the learning process of an open ended, essay-based course in a second-year degree engineering module in Brunei Darussalam. The essays were marked using a rubric by the student, a peer, and the lecturer, with students being pre-trained on the use of the rubric prior to the exercise. Comparison of the marks awarded by the different markers (student, peer, lecturer) showed that whilst there might be correlations between different markers (i.e. peer - self; or lecturer - self) for marks on certain sub-sections of the work, there was no overall correlation between marks for this open ended problem. This lack of consistency highlights the subjective nature of marking essay-based work, even with the use of a rubric. Feedback on the students' experiences was obtained using a questionnaire, and most students felt that the peer assessment exercise was a worthwhile activity which aided both their learning and students' motivation to learn. Analysis of student performance in the exam, after the exercise, identified that almost all students did better in the question linked to the exercise than in others, further reinforcing this student view. The poor mark concordance in this study indicates that both techniques are not suitable to quantitatively evaluate student performance, however they had a positive impact on student learning. It is recommended that this approach is incorporated in other open-ended assessments as a form of formative feedback with the provision of adequate tutor and student preparation.