Apple Watch Human Factors

watchThe big news in tech last week was the unveiling of the Apple Watch. I think it is a nice moment to discuss a range of human factors topics. (This topic may elicit strong feelings for or against Apple or the idea of a smartwatch but let’s keep it about the science.)

The first is technology adoption/acceptance. Lots of people were probably scratching their heads asking, “who wears a watch, nowadays?” But you do see lots of people wearing fitness bands. Superficially, that contrast seems to demonstrate the Technology Acceptance Model (TAM) in action.  TAM is a way to try to understand when people will adopt new technology. It boils down the essential factors to usability (does it seem easy to use?) and usefulness (does it seem like it will help my work or life?).

Fitness bands check both of the above boxes: since they are essentially single-function devices they are relatively easy to use and tracking fitness is perceived as useful for many people.

Back to the Watch, it may also check off both of the above boxes: it certainly appears easy to use (but we do not know yet), and because it has fitness tracking functions plus many others via apps it certainly may be perceived as useful to the same crowd that buys fitness bands.

The next topic that got me excited was the discussion of the so-called digital crown (shown below). Anne and I have previously studied the contrasts between touch screens and rotary knobs for a variety of computing tasks. Having both choices allows the user select the best input device for the task: touch for pushing big on-screen buttons and large-scale movement and knob for precise, linear movement without obscuring the screen. Using a knob is certainly easier than a touch screen if you have shaky hands or are riding a bumpy cab.


Two small items of note that were included in the Watch was the use of the two-finger gesture on the watch face to send a heart beat to another user–the same gesture many people intuitively think of when they want to feel their own heart beat.

Finally, the Watch has the ability to send animated emoij to other users. What was noteworthy is the ability to manipulate both eyes and mouth in emoji characters. I couldn’t find any literature but I recall somewhere that there is some cross-cultural differences in how people use and interpret emoji: Western users tend to focus on the mouth while Eastern users tend to focus on the eyes (if you know what reference I’m talking about or if I’m mis-remembering, feel free to comment).



There’s so much I haven’t brought up (haptic and multi-modal feedback, user interface design, automation, voice input and of course privacy)!