How do you know if you have a good source?

This is an important skill for a journalist to acquire. People talk to journalists in order to get their side across, to get famous, to get attention, to confess and get things off their chests. All of those motives, and others, can cloud the truth in the mind of a person talking to you. So how can you possibly tell if a source is reliable?

Here are some clues:

1. Confirmability. Check the veracity of some small parts of their story. You can find out if the dates are right, perhaps or if the weather he describes actually did occur on the day in question. If he says he met with so-and-so about the matter -- check with so-and-so and ask if they met. Good reporters put some questions into interviews designed just for this purpose. If there are errors in any of these relatively inconsequential matters, be very wary.

2. Proximity. Check to be sure that sources you are using were actually in positions to know what it is they are telling you. Can they show they were in the city on the day they are talking about, or in the job and at a level where the information they are passing to you would have credibly come to them? Guards in the federal court building, for example, do not usually know what goes on in judge's chambers.

3. Believability. We have a sense usually immediately about whether someone we are talking to is authentic, stable, coherent, lucid. If you have a sense that you may be dealing with a loon, heed that sense!

4. Motive. You do not have to use only the information that comes from sources with clean motives, the people who want to do good and to help change the world for the better. These sources are nice, but rare. What you do have to do is figure out why anyone talking to you IS doing it. Find out what is driving them and you'll know their biases. That will help you compensate for their blind spots and to know what you must discount and what might be useful.

5. Perspective. This is slightly different than motive. Think about where a source stands in relation to the topic you are discussing. Were they a top boss or an underling? Were they in a place where they could see all of the action, or only a part of it? Sources may tell you truthfully all that they know -- but you still won't be able to get the whole of a story from them. Be very aware of this.

6. Track record. This won't work the first time you talk to a new source, of course. But you will get a sense over a short period of how good the information is from a source who begins talking to you. You'll be able to see how accurate he or she is about small details, how complete in the context and perspective they provide. You'll hear from people objecting to the information these sources have given you and you can judge whether there is anything to those objections.

Never, ever build a story on just one source, no matter how credible you believe that source to be. This is the best check again being deceived and the No. 1 Rule of sourcing.