This paper compares high-graded essays to low-graded essays written by undergraduate students in Australia. The comparison is made in an attempt to identify the extent to which the use of the evaluative language termed "appraisal" contributes to their academic success. The appraisal theory has emerged from a further refinement of interpersonal meaning within a systemic functional linguistics (SFL) framework. The category applied is one of the appraisal systems which is ATTITUDE. A particular focus of the category is on APPRECIATION , a subsystem of ATTITUDE . The APPRECIATION is concerned with evaluating things, entities, a text, products, or processes. Therefore, APPRECIATION is the most dominant ATTITUDE expressed in academic discourse. Its expressions are very field specific. In the process of applying the APPRECIATION categories in academic discourse, some extensions and reworking of the categories were required. One extension is in Valuation categories which is a subsystem of APPRECIATION. This fine-tuning of aspects of the theory has enabled subtle but important differences to emerge in the kinds of evaluations expressed. Theoretical contributions and pedagogical implications for teaching English as a Second Language (ESL) in an English for Academic Purposes (EAP) course will be discussed.