Harry has a new baby. The baby needs a passport. Or does she?

It is easy to be swept away by visual design, by clarity of language, by transparency of navigation and many other things besides. It is easy to confuse those things – any of them, or all of them collectively – with effectiveness at getting things done. It is easy to praise or criticise web sites for how straightforward they are to pretend to use.

We try to get past those traps by user testing, drawing as far as possible on people characteristic of the service concerned. But all too often, we find ourselves asking testers, ‘what would you do if…?’.

In the end, there is no substitute for user testing being done by actual users trying to meet an actual need, which is one of many reasons why the idea that a web service can be finished before it is turned on is so delusional. Obstacles and difficulties will be found by actual users which the most well meaning and most realistic test users will miss altogether or respond to very differently.

So the news that Harry knows his baby needs a passport has a wider importance than it might first seem. Now all he needs to do is to remember that he probably needs to pack just a little more than he used to.