Behavior data collection is important in changing unwanted behaviors. You will often hear educators referring to ABC Data in IEP meetings. Understanding this acronym may help parents to affect positive behavior changes in the home, too. The "A" represents the word Antecedent. The "B" represents the word Behavior. The "C" represents the word Consequences. All behavior happens for a reason and this is a systematic way to record behavioral incidents in order to assess why the behavior may be occurring.
Antecedents are the circumstance that occurred just prior to the behavior occurring. Antecedents can sometimes be difficult to assess in the moment so having an outside person observe may be helpful. Antecedents can be based on the location (Mrs. M's classroom or the gymnasium), time of day (upon arrival, after recess), people (when a certain child or adult is present or absent), demand placed (do your math work, clean up) and many others.
Behavior is a clear and objective picture of what the child did or did not do. In describing behavior, it is important to record exactly what the child did or did not do rather than include statements of opinion or statements that can be interpreted differently. I would write something like, "He threw his papers on the floor and tipped over his desk" rather than, "He freaked out and got aggressive when I asked him to do his writing assignment". Another example would be, "She refused to answer my question" rather than, "She was mad at me and was being difficult by not talking to me".
Consequences are what happened or did not happen in response to the behavior. This is the specific action or non-action that occurred directly after the behavior was exhibited. The word "consequence" does not necessarily mean it was something negative. The consequence may be that the behavior was ignored, or the child was asked to clean up his papers, or the teacher asked the child what was wrong or the other students laughed at the child, or the child was sent to the counselor.
As you can see, analyzing behavior to gain a full understanding of the situation is more than just writing down what happened. To gain a better understanding one must know what happened right before and right after the behavior in order to change the behavior. The same behavior could happen for hundreds of reasons and it is important to get a complete picture of the situation in order to have good results in changing the behavior.