Time matters — and so does our visual displays. We can use visual displays that communicate effectively and efficiently. We can use visual displays that everyone can understand in a minute or less. Or we can use a variety of graphs, like the ones below.
Take a look at the following graphs. What do you notice about each one?
Figure 1. Four linear graphs.
If you said, “They look different” you win! Yes, they look different, but curiously the graph makers used the same data.
You might have thought “Wait a minute, why do we have such widely discrepant versions of graphs with the same data?” Many answers exist. Each person may employ differences to create their visual display —but the differences all arise from one source. The differences are due to nonstandardization.
Nonstandardization v. Standardization
Let’s start with standardization. Standardization means applying world-class specifications governing the delivery and construction of services, systems, and products (International Organization for Standardization, 2014).
Standardization leads to a standard or "an agreed-upon way of doing something” (Spivak & Brenner, 2001, p.1).When we lack standards, or do things in a nonstandard manner, we get different results. Always.
The lack of standards shows up in the four differently-constructed linear graphs with the scaling of vertical and horizontal axes, size of the axis lines, and the slopes of the line for each trend.
One of the consequences of nonstandard graphs is miscommunication. It takes time for people to learn to read and understand new graphs. Furthermore, with varying graphs decision making also can suffer. Scaling disortions may lead to a misunderstanding about the data, and then to poor decision making.
People who use nonstandard linear graphs no doubt want the best visual display for rapidly discerning effects. What can they do?
Standards have benefits
The previous question has an easy answer: standardize graphs. Standardizing graphs solves many problems. For example, doctors and technicians who read electrocardiographs (EKGs) experience the following benefits from a standard graphic display (Dubin, 2000):
- deep understanding of cardiac physiology
- develop a lifetime of practical knowledge
- rapidly comprehend the EKG (electrical activity of the heart)
The same benefits take hold for standard graphs as well. Graph readers can develop a deeper understanding of the subject matter. Practical knowledge of the content occurs more quickly and systematically. And the speed of graph comprehension accelerates.
For years Precision Teachers have enjoyed the previous benefits by looking at the world through the lens of a standard ratio (or "semilogarithmic") chart, the Standard Celeration Chart.
Simply stated, people who use Standard Celeration Charts never have to deal with differently sized axes. Also, the scaling will not shift. As a result, the slope of the line on each chart (when the same angle) means the same thing to every person who sees it. Without having to spend time figuring out the chart dimensions or what the symbols mean, Standard Celeration Chart (SCC) viewers rapidly get to the business of analyzing and interpreting the data.
A long history of good will and a positive focus spurred mottos such as “accentuate the positive,” and “Celerate, then celebrate.” In conjunction with Standard Charts, Precision Teachers developed a wonderful social practice called “Chart Shares.”
A chart share works just as its name suggest, people share charts. Charting sharing began with overhead projectors and transparencies of charted data. The figure below shows Og (the founder of Precision Teaching) sharing a chart.
Figure 2. Ogden Lindsey sharing a chart at the 2003 International Precision Teaching Conference.
When someone shares a chart the protocol involves going to an overhead projector (now an LCD projector or document camera) and talking about a chart for 1 or 2 minutes. That's right! It only takes 1 or 2 minutes to communicate the data story within the chart. People can communicate so much so quickly because of the standard view afforded by the SCC.
Figure 3. A current version of charting with our master of ceremonies Malcolm Neely directing Precision Teachers with their data.
Chartlytics recently had its first chart share. The following pictures show Chartlytics on display.
Figure 4. Pictures of two charts, both excellent results.
We believe the "learner knows best," and it is our privileged responsibility to adapt educational materials to our learners' needs. We do so by precisely measuring behavior, judging the outcomes of the performance intervention on a standard chart, and make changes if the data tell us an adaptation is in order.