By Erin Osterhaus, Software Advice.

It’s hard to evaluate a third-party recruiter in advance. The ultimate test, of course, is whether the recruiter brings you high-quality candidates. But you won”t know this until you’ve worked with that recruiter for months. You”ll certainly want to choose a recruiter who has experience hiring in your industry for the type of talent you need. But these basics just scratch the surface. To dig deeper, I asked three recruiting experts for some clever questions to ask a prospective recruiter. The experts:

• Jessica Miller-Merrell is the President and CEO of XceptionalHR, which provides businesses with recruitment strategies and human resources consulting, as well as the head writer for the well-known HR blog, Blogging4Jobs.
• Julie LaBrie is the President of BlueSky Personnel, a Canadian recruiting agency based in Toronto. She has worked in the staffing and recruiting industry for 14 years.
• Jennifer McClure is the President of Unbridled Talent, a consulting and advisory firm that provides services to clients in the areas of recruiting and HR strategy.

1. What is the internal turnover rate at your recruiting firm?

This is a great question to help you determine if a recruiting agency or Recruitment Process Outsourcing (RPO) provider you’re considering engaging has a history of hiring dedicated recruiters. The logic: if the agency vets its own recruiters thoroughly, there will be less internal turnover–a good indicator that the agency has a history of hiring dedicated individuals who will be equally dedicated to finding you great candidates. According to LaBrie, when she hires new recruiters for BlueSky Personnel, she tries “To find out first if they’re passionate about what they do and if they really care. At the end of the day, I need to find out if they’re going to dig for that person.”

2. What is the turnover rate of your past placements?

One of the most quantifiable ways to assess a recruiter’s dedication to finding the right person for the job is to determine if they have a track record of placing new hires who stayed on the job for an extended period of time. If their past placements have stayed on for at least two years, it’s a good indication that they know how to source candidates who have the skills required to succeed in a position and are a good culture fit with the employer. Conversely, a high turnover rate could indicate that the recruiter failed to adequately screen candidates.

3. What is your sourcing strategy?

Often the best candidates for a position are passive. In fact, for any given role, only 10 percent of the relevant talent is actively looking for a job. To access the other 90 percent of that talent pool, you’ll want to find a recruiter will do more than just post jobs and search job boards.

Great research skills are essential, because, LaBrie says, “We don’t always get the candidates we want through the postings, so we have to be very good researchers and diggers to get the information.” Your recruiter needs to have a proven method for doing this if they’re going to find those needles in the haystack.

McClure says it’s a good idea to ask how a prospective recruiter typically finds people, and what tactics they then use to engage the candidate. And, she notes, “Once they find the people, how do they connect with them, build rapport? Do they understand what the candidates are looking for to make a move? And how do they sell them on the opportunity, especially if it’s a passive type candidate who they found when they weren’t actively looking?”

4. How do you determine if a candidate fits the culture of the client?

Determining if a candidate will be a good fit with your company culture is absolutely necessary for your (and their) success. As the authors of Who: The A Method for Hiring found, “Not evaluating cultural fit was one of the biggest reasons for hiring mistakes. People who don’t fit fail on the job, even when they are perfectly talented in all other respects.”

McClure recommends asking the prospective recruiter what questions they use to assess whether a candidate would be a culture fit. For example: “Tell me about the best culture that you’ve ever worked in. What made it really enjoyable for you to work there? Where’s a place where you didn’t fit well and what was that like?”

She also emphasizes that it’s important to evaluate how the recruiter poses those questions to candidates. Companies should consider, ”Do they ask open-ended questions, and are they good at framing it in such a way that it really doesn’t give away what they’re looking for?”

Of course, it’s also important to know how the recruiter will get to know your culture before they can assess a candidate’s compatibility with it. Ask how the prospective recruiter would go about that. Miller-Merrell says, “Most third party recruiters will probably go through a checklist, or they’ll spend some time with you on the phone, or they’ll do some research on the Internet to try to get a sense of who you are as a company.”

You’ll have to do your part, too. As LaBrie notes, for recruiters, “What’s important for us when we’re trying to recruit for the company culture is that [the employer] shares everything–absolutely everything–with us. When it comes to who their hiring manager is, his style or her style, it’s very important for us to understand that.”

If you ask these questions up front, you’ll be well on your way to finding a recruiter who will source great people for the open positions your business’s growth has created–and with their help, you’ll be able to focus on what you do best, and keep your business growing.