"In a class on programming language concepts":

"at the University of California, San Diego, I assigned 12 students the project of writing a program in C++ in which they had to define the class 'boxer'. The summarize important points:

• ... no two people defined the same class.
• All 12 programmers claimed to have felt fairly satisfied with their own boxer classes. ... they underestimate the degree to which their class mismatched the new setting, even after hearing all of the changes that were necessary to make fit it.
• Naturalistic evaluations, although time consuming, were powerful tools for programmer illumination."