Their 5 considerations:

• Design for immediate access
• Keep gestures smart and simple
• Leverage clear mental models
• Design for real hand sizes
• Touch feedback is key

Usable: When you have a product that has a use, it needs to be easy to use. This means that is has to be intuitive. The person using it, shouldn’t have to think how he/she has to utilize it to fulfill his/her need. But this is not enough.

Desirable: It’s also a good thing that the person who’s going to use your product, actually wants to use it, not just because he/she has to. This can be done by use of a nice looking design and by making it fun and easy to use. For this, you need to tap into the emotional aspects of your product. (Also think outside the visual aspect, like the brand that might bring a certain prestige with it.)

Findable: When you have the best, most beautify and most usable product that ever existed, when no-one can find it. It might not even exist at all. People need to be able to find your product, but also find things inside your product (in case of a website, have a good navigation model and/or a search function).

Accessible: Your product should be accessible. This means for people with disabilities (about 10% of the population) but also from different devices (like mobile phones). This isn’t only good business sense (since you have an even larger target audience), but also because such requirements will become law in the future.

Credible: In order for a person to want to use your product, it has to be credible. So make sure that when it has an interface, it looks good (which style you use can depend on many things, from brand to personal preference). But there should also be information available about legal matters, security, privacy protection (when information is gathered),…

Valuable: It isn’t all about the people who will be using your product. In return it also has to deliver a certain value to you or your company, this can be in a monetary manner or in the form of customer satisfaction and reputation.

Finally, in the real world it is very difficult to have all of these points perfect. But it’s better to address each one of them and have a good result, than only address one and make that one perfect.

[From: Ambient Findability (book)]
[From: Semantic Studios]