When you’re deciding where to focus recruiting energy, it’s important to know how candidates have connected with you in the past. Applicant tracking systems (ATS) are supposed to give you that info, but many don’t do a fantastic job.

The problem is that a lot of systems rely on candidates to tell you how they learned about a job opening, or about the company in general. Usually, the software will ask the question and have users pick from a drop-down menu. That can cause problems when a candidate looks at more than one source of information before applying for the job (which is normally the case.)

Take this scenario: A candidate does a Google search for “account jobs in Philadelphia,” or something like that. The first result is a listing you posted on a major job board. The candidate clicks on it, reads the ad, then follows a link to your company “Careers” page to learn more.

By the time candidates like that actually make it to the application, which source are they going to choose? For your purposes, you’d want them to pick the job board, since that was what led to them to your Web page, and what got the job to show up on Google in the first place. But they could just as easily pick either of the other two. Or, they might pick something else entirely, because telling you how they learned about the position is far less important to them than actually applying for the job.

What’s the solution? One way is to choose an ATS uses tracking tags to electronically keep tabs on all the pages a candidate visited before getting to the application.

And if you use a system without that feature, you can still look at the results you get and just take them with a grain of salt. After all, when candidates are getting information from a variety of places, it stands to reason that all of those sources are important.

Read more about the inaccuracy of ATS sourcing data here.