Do you think applicant tracking systems has made internal/external recruiters more or less effective?

I'm not sure the ATS is the reason that many highly qualified candidates are being overlooked. I believe in many cases the underlying problem is the improper use of screening criteria, and this may be traced back to the published job description.

For example, in the field of human resources, it is fairly common for exceedingly talented and experienced HR generalists and managers to have no bachelors degree. Generally speaking, there is no compelling reason for a degree to be a bona fide occupational qualification (BFOQ) for these positions. And yet, my casual research indicates the vast majority of these positions indicate a BS or BA (even an unrelated one) is a requirement.

As a result, an otherwise eminently qualified candidate with a tremendous resume and glowing reviews and references will automatically be screened out by the ATS as "unqualified," while a marginally qualified candidate who happens to have a degree in, for example, Medieval Art will pass through to the next level of review.

I'm no lawyer, but I think employers who utilize these practices are just begging for discrimination complaints.

I'm with Steve, I think it's sloppy key word practice and ridiculous employer requirements that allows ATS systems to screen good candidates.

Using the latest buzzword for a position rather than it's established name, demanding degree's from everyone, even the janitor, and so on... that's what causes the problem.

I also think that there would be less need for automatic screening if companies targetted their recruitment drives better, for less volume and higher quality applicants.