This chapter proposes a methodology for small-scale prototyping using computational design and digital fabrication by incorporating Augmented Reality (AR), aiming at eliminating errors during the process. In the first stage, the chapter presents an algorithm for evaluating the accuracy of physical prototypes against digital design results, which have been developed in the context of an undergraduate course in computational design and digital fabrication. The errors that arise in each case are indicated based on quantitative and qualitative criteria. In the second stage, the process of fabricating corresponding structures by users with the participation of AR technology is proposed, providing a real-time correlation of the digital results with the physical outcomes throughout the fabrication process. Then, initial and new errors, which are occurred during computational design and fabrication, are compared, presented and discussed. Ultimate aim is the application of AR for eliminating errors in cases where computational design and digital fabrication incorporate human intervention.