It's been proven time and time again in studies (some are linked in these threads here).
I see that claim a lot, but when I look at the "studies" being cited, they rarely stand up to even cursory scrutiny about their methodology and the choice of test subjects.
These studies (or those making a case for TDD based on them) tend to do things like generalising results based on a few undergraduate students writing toy programs to draw conclusions about professional software developers working on industrial-scale applications, or using no unit testing at all as a control rather than say doing either test-first or test-last unit testing but not following the TDD process.
If you have better sources, please do share them. Developing a non-trivial application using two different techniques is rarely cost-effective, even without controlling for having different developers or experience in the two cases, so getting good quality data about the effectiveness of software engineering processes is hard.
Comments
It's been proven time and time again in studies (some are linked in these threads here).
I see that claim a lot, but when I look at the "studies" being cited, they rarely stand up to even cursory scrutiny about their methodology and the choice of test subjects.
These studies (or those making a case for TDD based on them) tend to do things like generalising results based on a few undergraduate students writing toy programs to draw conclusions about professional software developers working on industrial-scale applications, or using no unit testing at all as a control rather than say doing either test-first or test-last unit testing but not following the TDD process.
If you have better sources, please do share them. Developing a non-trivial application using two different techniques is rarely cost-effective, even without controlling for having different developers or experience in the two cases, so getting good quality data about the effectiveness of software engineering processes is hard.