UI design or Interaction Design?

You might have heard the term "interaction design" and wondered what's its difference with "UI design"!? Also if you already knew they are different you might have asked yourself why interaction design!? is it really important?

Well I know the two (UI and interaction design) overlap heavily. But believe it or not there's a difference! UI design deals more with the graphical elements of the interface whereas interaction design deals with designing the behavior of the system (I first heard this comment about interaction design on a podcast[1]). Interaction design involves enormous amounts of functional analysis, user analysis and task analysis in order to find out what the system must do, who the users of the system will be and how they are going to deal with the system. The designer then has to define the ways that users and the system will interact. This has to cater for user friendliness, provide good mental model of the system, be simple, effective and efficient.

Let's illustrate this with an example. Let's say iPod. Apple wants to enter the mp3 player market, they gather all the mp3s in the market and have a look at them. Their interaction designers think; Ok, with an mp3 player should list all the songs in different orders, play song, fast forward and backward, skip the song, change volume, etc. The next stage would be to identify the users, their age group, their behaviour, they mentality, their body attributes, etc. Next comes the task analysis, they'll have the users performing different tasks with the mp3 players, play songs, scan the list of songs, move forward in the menu, and everything else one can do with an mp3 player. Then they classify all these data and try to find the cons and pros of the current systems. For example they might say; something is wrong with going through the list, if someone is having hundreds of songs it takes a lot of time to scan forward and backward. Or random access to different parts of a song isn't intuitive, it's still a bit linear. They then will make prototypes of different ways to do all these tasks. Test these prototypes on users and the one that turns out to be the best (the wheely thing on iPod in this case), finds its way to the market.

Interaction with iPod is through the click wheel

I hope this gave you an idea of what interaction design is. You see there clearly is a difference between interaction design and user interface design.

Now that you know there's a difference let's talk about how important interaction design really is. Asking me I would say it should be on the top 3 priorities list. As I said earlier interaction design is designing the behaviour of the system, and to end users this means THE system. Because that's what they see of the system and deal with it. Believe it or not it makes them hate or love the system. The logic is so simple; exactly the way you hate or love someone for how they behave you hate or love something for how it behaves. Just take a look around you and count how many devices are fun to work with and how many aren't. That's exactly because of their behaviour and the way you interact with them.

For users the behaviour is THE system

So you see the interaction design is an important part of the product design which is usually overlooked by most of the companies who ask their graphical and industrial designers and their engineers to do it. When it's done properly, revolutionary products come into the market which drag the industry forward until the next revolutionary product is out. Examples of this are the iPod and iPhone. As Steve Jobs said[2] they reinvented the mp3 player and mobile phone thanks to interaction designers.

Refs:

[1] DC40 Interview with Kim Goodwin at User Interface 12, http://www.designcritique.net

[2] Stevenote, MacWorld Expo, 2007