As mobile UE designers, we face a constant challenge - how to offer our users lots of great features without creating a complex experience for them?

Within our team, we talk often about the experience we want to create - as people use our service for the first, second and future times. We work to create an experience where features are ‘revealed’ to users as they choose. We want this to happen progressively over time, so the user deepens their experience with the service under their own control.

Rather than purely taking in consideration what features to include in the service - which is what Kathy Sierra refers to in her Featuritis Curve below - we look at how the features could be unveiled so that the first visit isn’t overwhelming! On a mobile phone in particular, where we face constraints of limited screen space, network latency and navigation, it’s crucial that we fight the urge to tell a user everything at once.

Some users just want a simple search experience. Others will want to share what they find with friends by SMS. Others will want to broadcast a link to all their friends - direct to their favourite social network or microblog feed, (i.e. Twitter). We need to consider every one of those scenarios when designing.

For the first time user, our service is clearly a mobile search engine. We keep it simple and don’t offer stacks of features that will overload them either onscreen or cognitively. As users explore the service, they can discover other features - or ignore them - as they wish.

There is a concept in User Interface (UI) design called progressive disclosure, which Jakob Nielsen referred to in 2006.

A classic example of progressive disclosure in computer software is the ‘Print’ dialog box displayed when printing a document. First, you’ll see the dialog which shows only a few important options. If you want to, you can also ‘disclose’ a whole range of other settings/controls - the ‘advanced mode’ - peeling away at the layers of the onion until you get to what you need.

As a concept, progressive disclosure is similar to what we’re trying to achieve with the user experience of Taptu. We want this approach not only to work at individual widgets level, but to underpin the whole service experience as it unfolds to our users.

Have you used a service that gave you this feeling of revealing features? Or one that utterly failed at it by either overloading or hiding them too far away? We’d love to hear more about any you think do it well, or not so well!

Computers shouldn’t be unusable. You don’t need to know how to work a telephone switch to make a phone call, or how to use the Hoover Dam to take a shower, or how to work a nuclear-power plant to turn on the lights. — Scott McNealy (via Usernomics)

Contrary to popular belief, one of the biggest challenges we face when developing an application isn’t deciding what features to put in. It’s what features not to put in.

At least once a month, we get some of our users together to play with the latest prototypes we’ve created. But guess what? Few of those actually make it out of the lab. And that’s a good thing, if we put every feature in, you’d need a user manual bigger than the phone book just to get started!

So why do we hold back on all those funky features? As Kathy Sierra puts it, we want to make sure you can kick ass without having to spend too long below the Suck Threshold. In other words, keeping it simple means you can have a fun, enjoyable experience right away.

Even if we liked complicated, whizzy things with lots and lots of buttons, it just wouldn’t make sense to attempt it on mobile. We want fast, easy-to-digest content when we’re on the move, right?

With this in mind, we still want to add the features you’re most interested in. Is it the ability to post your search results to Jaiku or to send them by SMS? What would make your experience more fun? We’re always listening and we will put the best ideas in place.

If you want to make a suggestion, you can…

• leave a comment right here on the blog
• pop your ideas in the feedback form (you’ll need to register first)
• or drop me an email at vero@taptu.com

What would the mobile search engine of YOUR dreams do? (Other than telepathically order the right flavour of ice cream just when you want it, of course. We’re working on that one.)