The purpose of this research was to investigate the inclusion of a groove on the surface of lumber and how this effects processing accuracy and sensory acquisition skills when sawing with a handsaw. Samples with different grooves, visibility, and cutting area were used in the experiment. After cutting the specimen by cross cutting, the examinee evaluated whether the wood was “easy to cut”, “whether it was able to be cut straight”, and the force required for cutting as a skill acquisition. For the purpose of evaluating processing accuracy, the linearity and slope of the cut surface were measured using the cut sample. As a result, the following are suggested: (1) the groove increases the linearity of the cut surface; (2) the groove improves the sense of the wood being “easy to cut” and “can be cut straight”; and (3) the groove means that the cut can be made using less force.