Knuckle cracking is defined as a behavior that involves stretching or bending the finger joints and producing a popping or cracking sound. The sound is caused by gas bubbles bursting in the synovial fluid that lubricates the joints. People crack their knuckles for a variety of reasons. They might do it if they are stressed, if they are nervous, if they like the way it feels, if they like the way it sounds, if it's out of habit, etc. I choose to observe my roommate when we were in the library because I have seen him demonstrate this behavior on numerous occasions. I decided that knuckle cracking was anytime he went to bend, pull, or stretch his fingers to crack them, regardless if the popping sound occurred or not. The behavioral coding method I used was the partial interval method. I had one-minute-long intervals for over a period of 1 hour, which was a grand total of 60 intervals. Anytime my roommate would go to crack his fingers, I would write down a checkmark for that minute interval. After observing my roommate for an hour, he cracked or attempted to crack his knuckles in 9 of the 60 total intervals. He cracked his knuckles in the 3 minute interval, the 7 minute interval, the 16 minute interval, the 22 minute interval, the 32 minute interval, the 43 minute interval, the 48 minute interval, the 49 minute interval, and the 57 minute interval. The strength of using the partial interval method is that it's good for recording discrete and separated behavior. It's also good for recording short behavior that only lasts seconds. A weakness, however, is that some of the data could be left out. The idea is that you put down a checkmark once the beahvior occurs at least once in the time interval. The problem with this is that if the behavior happens again within the same time interval, there is no way to record that since a checkmark was already put down. As a result, some of the data might not get counted since you can only place one checkmark.