Consistency or usability feature?
The National Lottery have added a new Results Checker to their website. They use JavaScript to support the user enter their numbers into the boxes: you type a number and the focus of the mouse jumpts to the next box. First impressions are that this is a useful feature. However, it is conflict with the user behaviour of manually tabbing between fields. Given the audience profile I would make a call that this is acceptable; what percentage of the general population are familiar with the concept of using the tab key to move between field? My hunch would be a small number.
The feature fails in one small but crucial respect. It lacks internal consistency. They have an “orignal results checker” that does not use the JavaScript onFocus script. This leads to a conflicting mental model of the site. Some boxes automatically tab, other’s manually tab. Is this a lesson for interface designers to learn, when updating some parts of a site, don’t forget to refactor other parts of the GUI?
Tsk, tsk… If the behaviour is changed, it’s not refactoring (aka behaviour-preserving transformation).
Why are there two results checkers? Is the new one supposed to be replacing the old one? If so, should it be consistent with old behaviour or consistent with user expectations?
should it be consistent with old behaviour or consistent with user expectations?