Here is the wikipedia explanation of an extinction burst: While extinction, when implemented consistently over time, results in the eventual decrease of the undesired behavior, in the near-term the subject might exhibit what is called an extinction burst. An extinction burst will often occur when the extinction procedure has just begun. This consists of a sudden and temporary increase in the response's frequency, followed by the eventual decline and extinction of the behavior targeted for elimination.
Ok, now what exactly does that mean? Basically it means that when you are trying to decrease the frequency of a behavior, things will actually get worse before they get better. It makes sense when you think about it. Why would a child just willingly give up the small amount of control they have in their lives? (That's pretty much what most problem behaviors are; an attempt to control things). We can't expect them to give up without a fight, but if we stick to our guns and show them that this old way of behaving isn't going to work anymore, they will eventually give up the old behavior.
Why is this concept so important? Well, I believe that this is why a lot of parents feel that behavioral modification or various discipline techniques do not work. I can't tell you how many times parents have been in my office and told me "We've tried that and it doesn't work". Upon further discussion I find out that they tried it for a week or two and they felt like it made things worse, and they're right it did. However, if they had kept at it for another week or two they would have likely seen a decrease in the problem behavior.
For those of you who have ever watched Super Nanny, you might remember an episode where she is teaching the parents about effectively using Time Out. During this episode (and really it's any episode she ever done about time out), the parents have to return this girl to the time out spot over and over and over again, and her tantrum becomes worse and worse and worse. But in the end, and we're talking hours, she learns that the fit isn't going to work and she stays in the room for the required time. I remember going through this same process with a family when I did in-home behavioral consultation work. I returned the kid to time out over and over and over again. I set that timer over and over and over again. I was exhausted by the end of it, but it was what needed to be done to stop the behavior. Is this a lot of work? Yes!!!! Is it worth it in the long run? Yes!!!!
So next time you are trying a new discipline techniques, remember that it will get worse before it gets better. There is a light at the end of the tunnel.
This picture actually has nothing to do with an Extinction burst, but I found it when I was doing a Google image search and thought it was pretty funny. Here is the original source