A neighbor in winter gloves hands over a tablet. "The screen will not listen to my taps!" Rocket says. He taps it with his bare finger. It works.
Raven points at the gloves. "What do you notice?" she asks. "The screen shows pictures fine. It just cannot feel the taps through thick cloth."
Nova glows green. "This screen has two jobs," she says. "It shows and it feels. Would you like a hint? Which job failed?"
Some devices are input and output at the same time.
A touchscreen shows pictures, which is output. It also feels your taps, which is input. Two jobs share one piece of glass.
A headset with a microphone plays sound in your ears and takes in your voice.
A game controller takes in button presses and also buzzes in your hands.
| Device | Its input job | Its output job |
|---|---|---|
| Touchscreen | Feels taps and swipes | Shows pictures and words |
| Headset with microphone | Takes in your voice | Plays sound |
| Game controller with rumble | Button presses and stick moves | Buzzes in your hands |
| Smart speaker | Hears your command | Speaks the answer |
When a two-job device acts up, test each job on its own.
The tablet in the story passed the output test. Pictures showed up fine. It failed the input test, but only with gloves on.
A touchscreen feels a finger through a tiny electric change in the glass. Thick gloves block that change, so the tap never arrives.
Nothing was broken. The crew wrote the case down: input blocked by gloves. Case closed.
| Device | Is it both input and output? |
|---|---|
| Touchscreen | ? |
| Plain keyboard | ? |
| Headset with a microphone | ? |
| Printer | ? |
Two-job devices are everywhere once you start looking. A car dashboard screen shows a map and feels your taps.
A smart watch shows the time and feels your wrist moving. A laptop touchpad feels your finger and some can click back.
Excellent testing, Crew Technician! Tomorrow you will review the whole week with a big sorting game.