This inquiry researches the impact of digital tools on the design process and empirically tests the association between computer aided design tools and each of cognition and creativity in architectural practice. The paper analyses the ‘design-tool’ relationship and reviews research in the field of computers as an instrument for creativity, examines their deductions and conducts a case study. Statistical analysis of the case study suggests that three measures of creativity correlated significantly with the length of time a subject spends using the computer in design: rho=0.487, P<0.05 for elaboration of design ideas; rho=0.605, P<0.05, for volume of ideas; rho=0.687, P<0.05, for ideation variety. Also, the length of designer-computer interaction seems to scaffold various forms of design reasoning and help cognition: rho=0.591, P<0.05. The study found little evidence to support the notion that computers prevent other forms of knowing.