Shared cognition constructs, such as shared understanding and cross-understanding, are important factors for task performance in groups in organizations. Shared understanding defines the extent of common understanding of a topic among group members, whereas cross-understanding defines the extent to which group members accurately understand the mental model of another group member regarding a specific topic. Although research in different fields has focused on understanding the theoretical effects of these constructs, little emphasis has been placed on improving their development. In Information Systems and related fields, shared understanding of a domain is said to be facilitated using a domain ontology -a domain ontology is a description of concepts and their interrelationships in a domain, and are generally represented in a graphical way. However, there is a lack of empirical evidence to support the benefit of domain ontologies facilitating shared understanding. Accordingly, to address this knowledge deficit regarding the mechanisms to enhance shared understanding and cross-understanding, and the lack of empirical evidence regarding the effect of domain ontologies on shared understanding, this study aims to explore the effect of domain-ontology usage on shared understanding and crossunderstanding in novice group members. Accordingly, we propose a theoretical model that describes the effect of domain-ontology usage on shared understanding and crossunderstanding of domains in groups. To empirically test our model, we focus on a domain ontology developed specifically for providing shared understanding of the compliance management domain. We then tested our proposed model through an experimental research design. Our experimental research design considered a two-group, post-test only, randomized experimental design with a sample of student participants. The results of our experiments indicate that group members who use a domain ontology develop significantly higher levels of shared understanding than those who do not use a domain ontology.Secondly, group members who use a domain ontology have significantly better communication quality in terms of discussion efficiency and communication clarity than those who do not use a domain ontology. Our study also found that group members who use a domain ontology develop a significantly greater cross-understanding than those who do not use a domain ontology. The outcomes of this study are expected to contribute to both theory and practice. From a theoretical perspective, we contribute the model of domainontology effects in facilitating shared understanding and cross-understanding, as well as the operationalization and testing of the cross-understanding construct. From a practical iii perspective, we contribute by improving the understanding of the role domain ontologies can play as a tool to help improve performance in groups.iv