Purpose: In light of growing interest in the maker movement and electronic textiles (e-textiles) as an educational technology, the purpose of this paper is to characterize competence change in undergraduate students who participated in a semester-length course that used e-textiles. Design/methodology/approach: This qualitative and exploratory research study used semi-structured pre- and post-interviews with undergraduate students (N = 7) thinking aloud through novel tasks in order to understand their learning from a semester-long course involving e-textiles. This design was intended to elicit student thinking with commercial toys that differed from the types of projects they had completed in their course. A coding scheme was developed and organized into an analytical rubric to map depth of understanding in the three spheres of circuitry, computation, and crafting. Select cases of pre-post change were identified to illustrate growth in specific content spheres. Findings: Students' ability to reason through novel tasks showed growth in each sphere, provided that the student did not begin with a full level of sophistication in a particular area during the pre-interview. Although students may not reach normative or expert-like competence, there are demonstrable indications of growth for each of the dimensions. Originality/value: As e-textiles are increasingly turned to educationally, the creation and presentation of a rubric for describing competence in three spheres, especially the previously understudied area of crafting knowledge in e-textiles, is itself a useful contribution to the field. This is also an extension of e-textiles learning research into undergraduate instruction, an as-yet understudied setting for maker education.