Understand how modern touchscreens track multiple fingers simultaneously without ghost touches
Part of How Touchscreens Know Where You Tap
Educational content slides
One finger: Easy—one row + one column = one coordinate
Two fingers: Potential ambiguity problem!
Early touchscreens couldn't handle multi-touch. They'd get confused or detect "ghost touches" at wrong locations.
Why? The detection method created ambiguity about which touches were real.
Test your understanding with this quiz.
Why do early touchscreens (like ATMs) often only support single touch?
Complete this exercise and get AI-powered feedback.
Multi-touch enables rich interaction, but more fingers ≠ better design. Think about trade-offs.
Consider: Discoverability, memorability, physical comfort, accessibility, context of use.