This study investigates how a design-based research methodology is best suited to measuring the impact of a designed virtual reality experience to improve situated identity in Irish learners focusing on their attitudes, motivation, and confidence as Irish language learners. This paper describes the design of GaeltechVR: an immersive Irish language VR experience designed for the VIVE Pro. It also gives the results of a mixed-methods study to measure the impact in a local adult Irish language learner context. A questionnaire on situated attitudes and motivation to language learning (Ushioda & Dörnyei, 2009) was adapted for the Irish context to investigate a small scale sample of the local context's attitudes to Irish language learning. The participant's gameplay was recorded for analysis along with questionnaires on presence (Witmer & Singer, 1998), simulator sickness and an adapted questionnaire on their attitudes after the intervention.Using best practice in design-based research experiments (Nelson, Ketelhut, Clarke, Bowman, & Dede, 2013) the study had two main goals: To investigate the usability of the design of GaeltechVR and to measure the impact of the intervention on attitudes, identity and motivation in the local Irish language learning context.