There Are Two Kinds of People in This World
A common visual metaphor for zoom-level navigation in most online map applications is the trusty old zoom slider tool. It’s that railroad track thing with the handle that lets the user drag up or down to control the scale of the map (in effect, zooming in and out). The problem is, while the tool is wildly common, there are two ways of interpreting it and they are the exact opposite of each other.
The question a user must ask themselves in the milliseconds before they interact with the tool is…
Which way zooms me in?
There are only two options; two kinds of people in this world. You either drag that handle up or you drag it down. Aside from the visual cues of a "+" and "-" at either end of the track (those require mental decoding and use up precious milliseconds), there is a preference deep down in all of us as to which way we want to drag that handle to zoom in. And depending on which way your primal urges want you to drag that handle, you are either a Flyer or a Reeler.
Flyers perceive themselves as the slider handle. They are hovering over the earth and can dive down closer to it, or fly up away from it. The earth is stationary; the scale of the map is a factor of how closely they position themselves to it. To zoom in, flyers want to drag the handle down.
Reelers perceive the earth as the slider handle. They, themselves, are the stationary entity and they pull or push the earth nearer to their position or farther from their position. To zoom in, Reelers want to drag the handle up.
I Think I Know What You’re Thinking
1) If the metaphor used by the most common zoom tool out there is misinterpreted half the time, then isn’t there a better way?
2) Some interfaces have abandoned the track and just have the zoom in/out buttons that you click and hold.
Even if the zoom tool does not have that linear zoom track, the Flyer/Reeler bias will still be evident depending on which button is on top.
3) What about a horizontal orientation for the zoom widget?
A fine idea; it’s actually what we do. Our argument has been that many folks follow a left-to-right workflow, which lines up with the broad-scale then fine-scale principle of map zooming. But it does have a Western bias.
The zoom slider is handy, especially since the interactions allowed by a common mouse are rather limiting. My sense is that the Reeler method’s days are numbered and the Flyer method, which is a better fit for immersive 3D interfaces, will survive longer.
What are the corollary psychological implications of your preference? Flyers and Reelers. What kind of a person are you? Psych 101 at Central Michigan University does not qualify me to comment on those kinds of things; you’ll have to take a good long look at yourself and be willing to answer some tough tough questions about what you see.