Most prospective technical hires are looking for a pretty penny in return for their services. So how can you tell who will actually be worth it? The answer is effective interviewing.

When you seek advice on this issue, look for someone who has been there and done it. Someone who has interviewed many people for IT positions and has a proven track record. Jack Molisani, executive director of ProSpring Technical Staffing, fits the profile. He runs a staffing company that finds qualified contract and permanent staff for technology companies. He has interviewed thousands of people in the last several years and knows what to look for.

In IT, he said, it's not so much about the qualifications and certificates — though those play their part. The most important single skill in interviewing is being able to discern which of the candidates will actually be able to do what you want him or her to do.

Some bright fellows, for example, charm one and all during the hiring process and then can't deliver the goods in the real world. Others unveil magnificent rosters of their qualifications but can't turn their theoretical know-how into real work. A few come with unbeatable track records of success but somehow can't measure up. Molisani gives a good rule of thumb.

"If they can explain their area of specialization to a non-IT person in simple terms, then they understand what they do; if they can't explain it well, they probably don't understand it," said Molisani.

That may sound lightweight, but it is a surprising way to cut to the core of the issue. Is the person lost in a fog of esoteric concepts, or can she lay it out so others can follow what she is doing? Even if she can do her own specific task, if she can't relay the know-how to others, how will she be able to interact well with fellow IT workers? And, more importantly, how will she be able to tell the boss what she is working on so he gets it?

Once prospective candidates pass that acid test, there are a few others things to look for. Obviously, knowledge of a particular technical domain must be there for the area being hired. Molisani points to people skills as another point to assess in the interview phase. He watches to see if the prospect's gaze flicks anxiously all over the room, or if the person looks him in the eye?

Another point he stresses is not making the interview itself too stuffy and formal. Molisani wants to find out if the candidate is friendly or not. That means creating an atmosphere where the person has a chance to relax and be himself. Molisani has learned that this helps him to tell the difference between pretended friendliness and being truly personable.

Finally, Molisani encourages interviewers to pay heed to what the person asks about during the interview.

"You can learn more about people from the questions they ask than the answers they give," he said. "Pay attention to the questions the candidate asks you, as that reveals their investigatory aptitude."