Productivity soars when a computer and its users interact at a pace (<400 ms) that ensures neither has to wait on the other.

(a)  

The time to acquire a target is a function of the size of and distance to the target.

(a)  

The tendency to approach a goal increases with proximity to it.

(a)  

The time it takes to make a decision increases with the number and complexity of choices.

(a)  

Users spend most of their time on other sites, meaning they prefer yours to function the same way as others.

(a)  

Elements tend to be perceived as groups if they are sharing a region with a clearly defined border.

(a)  

Objects that are near to each other tend to be grouped together.

(a)  

People will perceive and interpret complex or ambiguous images as the simplest form possible, as it requires the least cognitive function.

(a)  

Elements that are similar tend to be perceived as a complete shape, group, or picture, even when separate.

(a)  

Elements that are visually connected are perceived to be more related than those with no connection.

(a)  

The average person can only keep 7 (plus or minus two) items in their working memory.

(a)  

Among competing hypotheses that predict equally well, select that which makes the fewest assumptions.

(a)  

For many events, roughly 80% of the effects come from 20% of the causes.

(a)  

Any task will inflate to fill the time given to it.

(a)  

People judge experiences based on how they felt at the peak and end, rather than a sum or average of every moment.

(a)  

Be liberal in what you accept, and conservative in what you send.

(a)  

People will best remember the first and last terms of a series.

(a)  

For any system, there is a certain amount of complexity which cannot be reduced.

(a)  

When multiple similar objects are present, the one that differs from the rest is most likely to be remembered.

(a)  

People remember uncompleted or interrupted tasks more than completed tasks.

(a)