The chart below is called a Standard Celeration Chart. This chart is used by a section of behavior analysts who use what is called Precision Teaching. First, let me explain precision teaching.
Precision Teaching was developed by Ogden Lindsley in the 1960's based off of Skinner's ideas about behavior. Precision Teaching, rather than looking at a count of behavior (how many times behavior happens) looks at fluency of behavior (how many times behavior happens in a designated amount of time). For example, rather than saying that Jimmy asked for help 3 times today, fluency says Jimmy asked for help 3 times in a 1 hour period. Fluency tells us much more about the mastery of a skill. Precision Teaching looks not only at whether the individual can perform the skill, but can they perform the skill quickly, and accurately.
The Standard Celeration Chart is used to see fluency of skills. You will notice on the left side of the chart it says "count per minute". That is because, precision teaching looks at the fluency of a skill which can be measured in a standard minute. The left side of the chart has numbers from 0-1000, and the bottom of the chart shows the days from 0-140 days. This gives you the ability to see 20 weeks of data all at once. You will also notice that the increments between the numbers, vary. The size of the chart between the 5 and the 10 is half the size between the 1 and the 5. Why? This is because, when you are able to perform a skill at 1 time per minute, and then increase to be able to perform the skill 2 times per minute, although it is only one more, you have effectively doubled your score. The chart takes these ratios into account by showing the growth of a skill to be much larger in the beginning from 1 to 2 as opposed to growing from 5 to 6.
The standard celeration chart also shows what is called 'celeration' meaning the growth of a skill over time. This growth is shown in a times format (x2) to show that the student is multiplying their skills at a rate of x2 and learning faster. We often use celeration by drawing a line to show that if the student continues to learn at the same rate, we will know how long it will take them to "master" a skill. If the student falls below this line, then we know we need to adjust programming to continue to keep them learning at a quick pace.
The big difference with those who use standard celeration charts, is that they are not allowing programs to run for more than a couple of days without making adjustments if the student falls below their learning speed.