1. The interviewer gives you a clear timeline for when a decision is expected, rather than being vague or noncommittal. When I'm interested, I make sure the candidate leaves knowing exactly what will happen next and when to expect to hear from me.
2. The interviewer asks about your timeline. When I'm especially interested in a candidate, unless I know I'll be making an offer within a few days, I start worrying about some other employer snatching the candidate up before I do. I say things like, "Is there any particular timeline you need to adhere to?" and "If our timeline conflicts with yours, please let me know, and I'll see if I can speed things up on our end."
3. The interviewer tries to sell the position or company to you. When I know I want to hire a candidate, I'll spend extra time talking about the advantages of the position and organization and will try to paint a detailed picture of things about the role or culture that might appeal to the candidate.
4. The interviewer spends a lot of time answering your questions. Whether or not candidates are strong contenders, I always ask what questions they have for me. But when I'm very interested in someone, it's much more in depth. I'll often probe to make sure that I've answered questions to their satisfaction and encourage them to be forthcoming about any reservations they might have.
5. The interview runs over the allotted time. If I'm not especially interested in a candidate, I'm looking for opportunities to wrap the interview up—not drawing it out. So if this happened to you, it's a very positive sign. (But at the same time, don't read anything into if the interview didn't go into overtime; I've hired plenty of people without the interview running long.)
6. After you're done, the interviewer introduces you to others or shows you around the office. Again, if I know I'm not going to move forward with the candidate, I don't waste anyone's time (including the candidate's) on these sorts of extras.
7. You hear from your references that the employer has called them. Reference-checking is time-consuming, so I don't start it unless I'm interested in a candidate.
Again, none of these are foolproof. An interviewer might do one or two of these without meaning anything. And of course, the interviewer can be very interested in you and still ultimately go with a different candidate. But when you start to see a pattern of the things above, you at least know that you're not out of the running.
Alison Green is chief of staff for a medium-sized nonprofit where she oversees day-to-day management of the staff as well as hiring, firing, and staff development. She is working with the Management Center to coauthor a book on nonprofit management. Her writings have been published in the Washington Post, the New York Times, Maxim, and dozens of other newspapers. She blogs at Ask a Manager.