### When Technicalities Interfere with Learning

**By Robb Cutler**

I was observing a middle school computer science class the other day working on a 3D graphics project. The teacher was describing how to define colors using the RGBA model. In this model, numerical values are assigned to the red, green, blue, and alpha components of the color. The red, green, and blue values are the amount of each hue present in the color. The alpha value represents the percentage of blending that occurs when the color is painted over another color.

Now, rather than provide the detailed mathematics behind alpha blending which, although accessible, would not have given the the students any real understanding of the concept, the teacher summarized alpha blending with one simple statement: "It's the invisibility factor, the smaller the value, the more invisible the color will be."

Is invisibility a completely technically correct explanation? Of course not. But it's certainly close enough and a more than reasonable description for middle school students. The fact is that sometimes (as this teacher correctly intuited) the technical jargon we use gets in the way of understanding for our younger students. Or worse, it makes a very interesting subject sound bland and boring.

Hans Magnus Enzensberger understood this too when he wrote "The Number Devil", a wonderful story about Robert, a boy who has mathematical dreams in which he learns about unreasonable numbers, prima donnas, and vroom numbers. The mathematics is sound; it's only the names of things that have been changed.

While there are certainly those purists (or perhaps puritans) who would be aghast at the idea of not using the precise mathematical monikers (irrational number, prime numbers, and factorials), Enzensberger realized that his terms not only sparked his young readers' imaginations, but also whetted their interest in learning more mathematics.

In computer science, do words such as polymorphism, boolean, conditional, and algorithm not stimulate the imagination in ways that Enzensberger and the middle school computer science teacher do with their unreasonable numbers and invisibility factors? Are we unintentionally turning younger kids off to computing with our language? And, if so, how can we fix things?

Robb Cutler

CSTA Past President