This paper addresses relevance in legal information retrieval (IR). We investigate whether the conceptual framework of relevance in legal IR, as described by Van Opijnen (2017), can be confirmed in... Show moreThis paper addresses relevance in legal information retrieval (IR). We investigate whether the conceptual framework of relevance in legal IR, as described by Van Opijnen (2017), can be confirmed in practice. The research is conducted with a user questionnaire in which users of a legal IR system had to choose which of two results they would like to see ranked higher for a query and were asked to provide a reasoning for their choice. To avoid questions with an obvious answer and extract as much information as possible about the reasoning process, the search results were chosen to differ on relevance factors from the literature, where one result scores high on one factor, and the other on another factor. The questionnaire had eleven pairs of search results. A total of 43 legal professionals participated: 14 legal information specialists, 6 legal scholars and 23 legal practitioners.The results confirms the existence of domain relevance as described in the theoretical framework by Van Opijnen (2017). Based on the factors mentioned by the respondents, we can conclude that document type, recency, level of depth, legal hierarchy, authority, usability and whether a document is annotated are factors of domain relevance that are largely independent of the task context.We also investigated whether different sub-groups of users of legal IR systems (legal information specialists who are searching for others, legal scholars, and legal practitioners) differ in terms of the factors they consider in judging the relevance of legal documents outside of a task context. Using a PERMANOVA we found no significant difference in the factors reported by these groups. At this moment there is no reason to treat these sub-groups differently in legal IR systems. Show less
