Recently, comparative judgement has been introduced as an alternative method for scoring essays. Although this method is promising in terms of obtaining reliable scores, empirical evidence concerning its validity is lacking. The current study examines implications resulting from two critical assumptions underpinning the use of comparative judgement, namely: its holistic characteristic and how the final rank order reflects the shared consensus on what makes for a good essay. Judges' justifications that underpin their decisions are qualitatively analysed to obtain insight into the dimensions of academic writing they take into account. The results show that most arguments are directly related to the competence description. However, judges also use their expertise in order to judge the quality of essays. Additionally, judges differ in terms of how they conceptualise writing quality, and regarding the extent to which they tap into their own expertise. Finally, this study explores diverging conceptualisation of misfitting judges.