HCI Design guidelines

What is the core idea behind Shneiderman's 'Golden Rules of Design'?

8 principles like consistency, feedback and error prevention for interface design.

Nielsen's heuristics can be used for two main purposes. What are they?

As design principles and as an expert based evaluation method.

'Recognition rather than recall' means...

Objects, actions and options should be visible so users don’t need to remember them.

What does the 80/20 Pareto Law suggest for interface design?

20% of functionality accounts for 80% of usage so prioritize that 20%.

The Principle of Least Effort (Zipf) suggests interface designers should...

Make frequent actions easy and risky/rare actions harder to reach. Examples include putting common menu items at the top and requiring more clicks for dangerous operations.

What is the principle of Least Astonishment?

Match system behavior to user expectations/mental models.

What did the Kurosu & Kashimura (1995) cash register study find about 'Apparent vs. Inherent Usability'?

Usability ratings were more correlated with beauty (aesthetics) than actual usability. This links to the Aesthetic Usability Effect, things that look better tend to perform better in usability tests, even if not more functional.

What is a 'mode' in interface design, and why can it be problematic?

A setting that makes the same control behave differently (e.g. Caps Lock), problematic if the mode change isn’t obvious. An example would be when a laptop with no Caps Lock indicator light, which is confusing when entering a password.

What does the 'Equal Opportunity' principle recommend?

The place where you see a current value should be the same place you change it. Examples include spreadsheet cells, car dials and loan application sliders where you see and adjust the value in the same control.

According to Fitts's Law, the time to acquire a target depends on...

The distance to the target and its size. Larger and closer targets are faster to acquire, screen edges are especially easy to hit with a mouse since the cursor cant overshoot them.

What does Hick's Law state?

The time to reach a decision goes up as the number of choices increases. More options on screen slow down decision-making, which is why focuses, curated interfaces feel faster to use.

What does 'Signal to Noise Ratio' (Tufte) warn against in design?

Too much visual density, which degrades viewer interest and attention.