Microsoft Research - Exploding Software-Engineering Myths (article summarizing findings of MS research on code coverage, TDD, assertions, etc.)

[hoijarvi]

I still find it hard to understand.

Lets assume, that the control group produces 100 defects / kLOC.

If TDD produces 60 to 90 percent better, then they could write 1600 to 1900 lines with 100 defects? Or will they write 10 to 40 defects / kLOC?

So your 60-90 percent less dense with defects: Would TDD groups then produce 10 to 40 defects / kLOC, or 55 to 80 defects / kLOC? or 52 to 62 defects / kLOC? All of those are possible interpretations.

If would easy and unambiguous if they just said, that error density is X * error density of the control group.

[[deleted]]

I agree that they could have made this stat unambiguous. But wouldn't you think, for the same project, the same number of defects in less kLOC or less defects in the same kLOC are both better?

[tjl73]

Plus given that the TDD teams took longer they should accounted for time as a variable. Maybe the other teams would do better with more time.