Inc.com columnist Alison Green answers questions about workplace and management issues--everything from how to deal with a micromanaging boss to how to talk to someone on your team about body odor.

A reader asks:

I manage a small team of researchers. I have one team member, Anna, who does some great work but also has a habit of claiming others' work as her own.

In her recent performance review, she spoke about work she'd done on a project that I know was actually done by a colleague because (unbeknownst to Anna) I'd worked closely with the colleague on it and knew what he'd done on it. She also referred to a set of guidelines she'd "developed" for our external partners (which I was surprised by as we already had one, again written by a colleague some time ago). When I then looked at it, it was clear that she'd simply created a new document with a title page and her name on it but copied and pasted the guidelines from a document she'd found in the colleague's folder, just in a different order. She has also sent documents to me that she's "put together with ... [a colleague]" but in actual fact the colleague has written it and asked her to proofread. Rather than send it back to the colleague, she's forwarded it directly to me as though it's a joint piece of work.

I'm finding it difficult to evaluate her performance (and that of her colleagues) because I find myself questioning whether it's her work. I want to raise it with her and try to frame it as constructively as possible. Any thoughts would be much appreciated!

Green responds:

This is serious stuff.

Anna is lying to you, and she's doing it to try to accrue benefits to herself at the expense of her co-workers. That's a serious integrity problem, and it's not one you can have on your staff.

If she's willing to lie to you about this, you won't be able to take her word for anything. That's unworkable in an employee.

This isn't someone fluffing up their work on a project around the edges. She copied someone else's work and put her name on it. She's lying to you and she's stealing from her co-workers.

So this shouldn't be about finding a way to frame it as constructively as possible or even about trying to figure out how to know if something is really her work. It needs to be about telling her extremely clearly that this isn't OK and that she's created a situation where you can't trust her.

And it also needs to be about deciding if you can even keep her. Lying, especially a pattern of lying, is the kind of thing that you need to fire over.

But, before you decide anything in that regard, you need to talk to her. I'd start this way: "You mentioned in your performance review that you'd developed a set of guidelines for external partners. I took a look at it, and it appears to be the document Jane wrote a while ago, but with a title page with your name on it. How did that come about?" And then you go to: "You had also mentioned work you did on the X project, but my understanding is that work was done by Bob. What can you tell me about that?" (Talk to Bob beforehand to make sure that Anna didn't play a role on the project that you didn't know about.)

How she handles this will give you useful information. If she digs in deeper and tries to keep the lie going, that means you have someone on your team who's willing to lie to your face even when you've told her the jig is up (and you can't have that). But, who knows, maybe she'll tell you something you didn't realize that exonerates her, so it's important to have the conversation and give her a chance to do that, just in case. But assuming that doesn't happen, then the next step is this:

"I'm seeing a pattern of you claiming other people's work as your own. This is a very serious thing, to the point that I'm questioning whether we can keep working together. I need to be able to take you at your word when you tell me things because the alternative is that I'd have to check up on everything you tell me, and that's not workable. I need to think about where we go from here, but meanwhile is there anything you want to tell me about what's going on?"

But unless you hear something in this conversation that changes your understanding of what's been happening, you're going to need to let Anna go.

Want to submit a question of your own? Send it to alison@askamanager.org.