Identity has been theorized to aid in student persistence within STEM disciplines. In this study, science and chemistry identity were defined as being recognized as a science or chemistry person within the classroom. To generalize the effects that identity has on student persistence, a measurable construct must be defined, operationalized, and tested in multiple settings with different populations. This project addressed the first step in the process, defining the construct and grounding it in an established theoretical framework. This qualitative project utilized a previously described physics identity framework, with sub-constructs of performance/competence, recognition, and interest, as a starting point for the alignment of students’ perceptions of identity to the broader theoretical frameworks of identity. Nine semi-structured interviews were conducted with students from a range of chemistry courses at Portland State University. The interviews consisted of questions pertaining to the sub-constructs of identity. Thematic analysis was used to define emerging themes within student responses. These themes were found to align with an array of affective constructs, including mastery experiences, verbal persuasion, vicarious experiences, situational interest, and mindset. These constructs will be used to develop an identity measure for chemistry education that is grounded in the broader theoretical frameworks of identity.