Last week, after a conversation with a colleague, I tweeted “A User Experience is greater than the sum of it’s Touchpoints”. It seemed such an intuitive statement, but almost immediately after hitting [Enter] I started to ask myself “what on earth does that really mean?”. Since it was retweeted quite a lot I thought i’d better spend some time thinking about it!
Space Time; the Final Frontier; As User Experience professionals we expend so much effort on the visual (layout, navigation, aesthetics, etc.) we sometimes forget that our users experience things over time. Whether a few seconds – page to page, or a few weeks – visit to visit, the time between touchpoints causes things to happen to memory which changes the context of the next (and subsequent) touchpoints.
Human memory; Users may remember or forget particularly good or bad interactions, changing the context and their perception of the next touchpoint, a perception they would not have if they only interacted with that single touchpoint.
Computer memory; The system may remember or forget information from one touchpoint to the next (usernames, reference numbers, last items viewed, last state, etc.), changing the context of the experience (for good or bad) from that which they would have experienced if they had only interacted with that single touchpoint.
The takeaway? Do what Kirk did to Khan, but go one better – think in the 4th dimension, time.

I would also add the aspect of taking into context a users emotional state. Their emotions, whatever it is, might not be a result of the experience you defined (past or present; single or multiple touch points) but might be “baggage” they bring to the table. So, in the end it would look like: their baggage + your UX = the final user experience.
Time is indeed an important component. A designed needs to be considered not just for how it will be used in the first few encounters, but a month later, or even after quite a bit more time passes. The time slice considered for granular design details may be small, but we have take a broadly temporal view of the design as whole. This is especially important for, say, enterprise applications that may be used every day, but it’s also important for applications and interfaces that are more sporadically used.
For Interaction 10 I presented on time as an important design factor and broke things down a bit. It’s viewable here: http://www.ixda.org/resources/maria-cordell-interaction-design-fourth-dimension.
I’m hoping to get back to expanding on these ideas before the end of the year, so your post was a good reminder that I don’t have much time left to do that!
Cheers,
Maria