I use this behavior chart when I realize my student needs more support in knowing when they are or are not on task. It is a simplistic version of a behavior chart, but focusing on one behavior at a time gives the best results. I don't tally them for every instance of being on or off task, but I do for as many as I can. I don't begin this sheet without a conference with the student, and/or with the parent depending on the types of behavior I'm seeing.
This is done in conjunction with a reward goal. I begin with an easy to achieve the reward, then I increase the number of On-task tallies or reduce the number of Off-task tallies required to achieve the reward. Rewards include- seating choice in the classroom, earned jobs, special privileges, points for their group, or a small item like erasers. At the end of the week, or daily, I send the sheet home to communicate with parents. The goal is behavior modification and an increase in On-task behaviors. This type of behavior modification may get worse before it gets better and usually takes a few weeks to see the level of improvement you're looking for. Don't give up!