For novice users, is it better to keep the entire UI visible, or to display menus and pop-ups?

Question

I am working on a user interface for a point of sale system to be used in a retail store. This interface will be used by volunteer cashiers, many of which have only basic computer skills.

With this audience, is it better to build a user interface that keeps everything visible at all times, or to provide a simplistic interface that displays pop-ups and menus for more advanced features?

To put it another way, would a novice user prefer to see as much of the interface as possible at one time, or would they prefer to see a very simple interface at first, with more complexity revealed only when necessary?

Answer 1

In general, displaying a large field of many options is less preferable than showing a smaller subset of higher-level categories with clear labels, allowing users to drill down into successively more narrow categories (assuming we're talking about a "select-a-product" type task.)

If there are multiple paths or options involved in a checkout flow, then generally you want to progressively reveal advanced options as they become necessary.

That's a vague answer, so maybe it's helpful to consider the context of use for most of these volunteer cashiers - will they have continual exposure to the UI over time, such that they'd be able to learn some elements? Are they likely to have only intermittent contact with the UI, occurring at far-apart intervals?

Also, what kind of point of sale system are we talking about? PC running a web UI? Windows OS application? Touchscreen kiosk?

What kind of data entry is going to be involved? Will volunteers need to select merchandise from a fixed menu? Simply enter in prices? How often does the inventory change?

Sorry to answer with so many questions, but the right answer might depend on the details. If all else fails, you might want to find a retail outlet near you with self-checkout kiosks (many grocery store chains here in the U.S. have them, as well as Home Depot. IKEA tends to have them as well, though not in all locations). I think the use case is similar to what you're dealing with: users who come into infrequent contact with a point of sale system and need clear and concise choices throughout the checkout process.

Answer 2

I would consider putting commonly-used features visible at all times in an easily accessible place. This way, users don't have to go through so many layers of navigation for everyday tasks. Any features that are not for everyday use can be hide away in another place and revealed only when necessary.

Answer 3

I believe that you should not display menus or pop-ups. A lot of people are like me: when they see a Tip Window or something like that they immediately disable pop-up windows and close the window. I would not advise it. Just try aiming at a simple-to-understand-at-first user interface and let them go find to tutorials later on if you UI is that complex.

Answer 4

The more details you have on the screen, the more intimidating it is, so I would definitely go for the gradual reveal, but with the following considerations:

• thyrgle pointed a problem with pop-ups, so I would say you can either change the current screen or use modal dialogs when user action is required.
• make sure that the most common scenario can be accomplished very fast with a minimum number of clicks. Once people get used to the system, prompting them and stopping their flow will be a problem.