We all know the feeling. You’re trying to install an application or scan in a picture and slow but steady the progress-bar keeps progressing… and then the moment of truth arrives.
The bar approaches 99% and suddenly time seems to stop. Time after time you’ll end up frustrated. Well now they may have find a solution to that.
A few people from the Carnegie Mellon University have done some research on the effect of the progress-bar. The results can be found in this relatively short and easy to read paper. For people who don’t have the time to read 4 pages, here is a short summary
The researchers came up with nine functions to monitor the progress:
- Linear (constant progression)
- Early pause (almost linear, very slow around 25%)
- Late pause (almost linear, very slow around 75%)
- Slow wavy (three big steps separated by pauses)
- Fast wavy (increments in small, quick steps)
- Power (accelerates)
- Inverse power (decelerates)
- Fast power (rapidly accelerates)
- Inverse fast power (rapidly decelerates)
They animated every progression in the form of a real progress-bar which they then used for testing. In total around 22 people have tested all the progressions.
They where shown two bars at the same time and then had to pick the one which appeared to be progressing the fasted. (they all took 5.5 seconds). They results of this where processed and conclusions where drawn.
The nine functions can be divided into three groups. Three functions where perceived to progress slower than linear, which are: late pause, slow wavy and fast wavy. Inverse fast power, inverse power, early pause and linear where perceived as ‘normal’ progression.
Power and fast power where perceived as being the fastest.
The researchers had some interesting findings, these are the two most important ones: Participants perceive progression with pauses slower than linear progression. Progressions which accelerate are perceived as being the fastest.
They do add that a system which has a stable progression should also show a linear progress-bar. However it’s very interesting for systems to fake accelerating progression to improve the user experience.
When the progression can’t be monitored accurately, then a progress-bar often isn’t the best choice. In that case you’re better of using a repetitive animation. In this case a proper maximum speed should be defined else it might result in a nauseating experience.