With the shift to next generation digital assessments, increased attention has focused on Technology-Enhanced Assessments and Items (TEIs). This study evaluated the feasibility of a high-fidelity digital assessment item response format, which allows students to solve mathematics questions on a tablet using a digital pen. This digital ink approach allows students to hand write their responses while showing their work in a digital format. Responses obtained using the digital pen were compared to both paper- and type-written response formats in a repeated measures design. Results showed that students liked the digital pen format and preferred it to the type-written format, but continued to rank the paper format as their first preference. Statistical comparisons showed no significant differences in student performance across response modalities, but means fell in the predicted order favoring digital pen over keyboard for the digital response formats. Results are discussed in light of software usability, technical issues during data collection, and statistical power for detecting effects in the study.