There are lots of ad-hoc rules that people are happy to propose about passwords, such as: Pick a phrase you can remember easily, and then use the initial letters. A random short sequence of letters, ...
There are some important thresholds of frame rate in video playback that effect whether or not animation appears fluid. This wikipedia page about Visible Frame Rate suggests that a framerate of 60 ...
A common reason to use Conventions and standards in Human Computer Interaction is to limit the cost of Context Switching. I searched to find general evidence of the cognitive costs of context ...