# Exceptional usability

> About exceptionally outstanding usability.

About exceptionally outstanding usability.

## Ease of learning and ease of use

Something that is easy to learn and something that is easy to use are different concepts.

For example, a bank ATM is easy to learn, but cumbersome to use. Because people use ATMs only once every few months or so, it is important that they be easy to learn even if they are somewhat cumbersome to use (there are too many buttons to press, and carrying out the task takes a long time). By contrast, a bank teller who has to handle a great many tasks would need an interface that is easy to use even if it is somewhat difficult to learn.

Of course, the best interface is one that is both easy to learn and easy to use. As a designer, one should think intensely in order to find a way to satisfy both.

If one unavoidably has to make a trade-off and choose one of the two, then one should choose consciously and explicitly which direction to go in (ease of learning vs. ease of use).

## Easy-to-learn interfaces

Meanwhile, how does one make an easy-to-learn interface? We can categorize a few reasons why an interface is easy to learn.

1. Cases where it is easy to learn because it is similar to an existing way
2. Cases where it is easy to learn because it accords with human nature (e.g. <Donald Norman>'s [natural mapping](https://wiki.g15e.com/pages/Natural%20mapping.txt) generally accords with human nature)
3. Cases where it is easy to learn because it has high learnability. (e.g. an interface designed so that functions can be discovered naturally, and in a direction that supports [habit formation](https://wiki.g15e.com/pages/Habit%20formation.txt))
4. An interface that has a small number of features relative to the range of things one can do with it. (See: [Capabilities over features](https://wiki.g15e.com/en/pages/Capabilities%20over%20features.txt))

If possible, it is better to aim for 2, 3, and 4 rather than 1. This is because among interfaces that fall under 1, there are many cases where they are easy to learn merely because they are familiar, even though the way itself is bad. <Jef Raskin> criticizes calling such interfaces "intuitive interfaces" in [The humane interface](https://wiki.g15e.com/pages/The%20humane%20interface.txt).