One way an intervention can affect a behavior is by changing its level. The level is the average height of the behavior within a phase. Let’s say that this graph shows the number of times my cat scratches the couch every day. Although the specific number of times changes a little bit every day, the level of her scratching is about 16. You can see this mathematically if you add up all of the data points and divide the total by the total number of data points. The average of them all is about 16. The level can be a good way to summarize the data within a phase.
Feel different, hope we have some one else here and post something. I feel the behavior course needs this kind of study, but still little confuse about the main ideas. May be eventually get there when I finish this study.