Along with the information technology rising, Computer Aided Design activities are becoming more modern and more complex. But learning how to operation these new design tools has become the main problem lying in front of each designer. This study was purpose on finding problems encountered during code-based design tools learning period of designers, especially those influential factors. The research was based on two design protocol analysis studies. A pilot study was performed for research details adjustment. Three selected participants have been told to complete one sketching work with two different digital design tools. A 30 minutes teaching was performed on each participant. Processing was introduced for data analysis. We found digital methods can be used to performing design process analyzing. We construct a multi-scale analyzing structure for design process and we demonstrate the possibility of pure quantitative study of the design process.