This concurrent triangulation mixed method design study describes the influence of a science education seminar (SES) on the learning assistants' (LAs) perceptions of their roles in the classroom. The SES was developed to train undergraduate students as LAs at a Southern liberal arts college in the USA. The focus of the seminar was teaching the LAs how to guide students through the learning process. Using the LAs perception survey, a pre and post-survey was administered to a conveniently sampled nine LAs to observe changes in their perceptions of their role. An interview was given to eleven LAs at the end of the seminar to investigate their perception of the seminar and any changes that had occurred in their perceptions of their role as LAs. A test of the significance of the quantitative data was done using the Kruskal-Wallis Chi-square and the qualitative data were analyzed using Atlas software. The pre- and post-survey results indicated that the LAs' perceptions about their roles changed during the semester. During an interview conducted at the end of the seminar, LAs indicated that their views on how to approach students' problems had changed mainly due to the seminar. The interview also showed that the LAs felt that the seminar was valuable because it changed the way they viewed themselves in their role. Results from this study inform colleges of the importance of training LAs.