The Mathematics of Human-Computer Interaction

Short Form


Why do most computer interfaces flop? Why do so few succeed? Is it magic, or is there a method to the madness? Learn about some of the mathematical underpinnings of human-computer interaction, starting with Fitts' law in one-dimension and ending with the Accot-Zhai steering law in two.


Face it: interacting with computers can be painful. To click a button, your brain must perform the necessary mental gymnastics to get your hand to trace the appropriate path to get the pointer from point A to point B. That we can accomplish this task with any precision is amazing, but it’s still harder than it should be.

As it turns out, the time required to move your mouse pointer is a function of the distance to and size of the target area. What’s more, we have formulas to quantify this:

  • Fitts’ law (one-dimension)
  • Accot-Zhai steering law (two-dimensions)

We’ll talk up these laws, analyze the design of some popular websites, and see how they could be improved (and quantify this improvement).

Speaking experience

This is my first talk at a conference.


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    Daniel Sauble

    Puppet Labs


    A front-end engineer at Puppet Labs in Portland, OR, Daniel has a B.S. in Computer Science from Baker College and began an M.S. in Electrical and Computer Engineering from Purdue University before dropping out to work full time at Puppet Labs in January 2012.

    Heavily vested in internships throughout school, since 2004 he’s worked at IBM, Intel, HP, Nike, and FEI. Finally, in 2011, he found his area of passion—Human-Computer Interaction—and is doing his best imitation of a sponge, working with a world-class UX team and absorbing as much knowledge as humanly possible.