[ReptileMan]

>they don't need to be written by different people

If you make logical error in the code, chances are you will make logical error in the test that tests that segment too.

A big problem with tests is making sure they are correct.

[almost]

From my experience though I often do make logical errors in my code but not in my tests and I do frequently catch errors because of this. I think thats a fairly normal experience with writing automated tests.

Would having someone else write the tests catch more logical errors? Very possibly, I haven't tried it but that sounds reasonable. It also does seem like that (and the other things it implies) would be a pretty extreme change in the speed of development. I can see it being worth it in some situations but honestly I don't see it as something practical for many types of projects.

What I don't understand is saying "well we can't do the really extremely hard version so let's not do the fairly easy version" which is how I took you original comment.