It’s always nice to discover new functionality in interactive systems, especially when watching people use such systems in the wild. When travelling in an elevator, I recently saw a nice solution to the main problem with elevator user interfaces: how to deselect a mistakenly pressed floor button.
Although elevators have a very simple user interface—press the button that corresponds to the floor one wishes to visit—this simple interface breaks down when passengers mistakenly press the button for the wrong floor. Elevator buttons are either in the default off state or they’re in the lit state after being pressed by passengers. There’s usually no way for passengers to deselect a floor after it’s been selected. Only the elevator itself can deselect the button when it arrives at the corresponding floor.
Like most nice designs, the solution to this problem is incredibly simple: treat each floor button as a toggle button. After pressing an incorrect floor button, passengers correct their mistake by pressing the floor button again to reset it to the default off state. The downside of this kind of functionality is that it’s hidden and therefore not easily discoverable, except perhaps by accidentally pressing the incorrect button again en route to a neighbouring button. However, learning from other elevator passengers is a useful and easy way to learn.
One of the best ways of teaching users how a software or physical product works is through feedback. Some types of feedback are explicit, such as a well-placed error message presented when we fill out an online form field incorrectly, or a supportive tick when we fill out the field correctly. Other types of feedback are implicit and require us to learn a connection between the feedback and the correct way to use an object or system. Regardless of type, the best feedback occurs naturally and at just the right time.
A nice example is the implicit feedback provided by the entry and exit barriers in the stations of the London underground. To pass through a barrier, passengers insert their ticket at the front of the barrier’s ticket-validation machine and retrieve it from the top. Because a passenger’s primary goal is to pass through the barrier, once the barriers have opened, their goal is complete. Retrieving the ticket for later use is not a primary goal and therefore passengers are likely to forget their ticket.
To prevent passengers forgetting their ticket, the barrier doors don’t open until the ticket is taken from the ticket-validation machine. On first use, some passengers may wonder why the barrier didn’t open even after the ticket passed successfully though the ticket-validation machine and appeared at the top. However, because the natural next step is to take the ticket to inspect it for damage and reinsert it into the machine and try again, the act of taking the ticket opens the barrier and starts the learning process. The next time the passenger passes though a barrier, the same behaviour reinforces the passenger’s mental model of how the ticket barrier works. This is feedback at its best.
We’re all familiar with this type of feedback, of course. It’s exactly the same type of feedback we get when using an ATM. Before dispensing cash, ATMs require that customers remove their card from the machine. Banks learnt long ago that customers forget their ATM cards after taking their cash from the machine. Why? For exactly the same reason passengers forget their underground tickets: once we’ve accomplished our primary goal, we tend to forget about the supporting tasks or objects required to accomplish our primary goal. As soon as customers have taken their cash from an ATM, their primary goal of withdrawing cash is complete. Retrieving an ATM card is not a primary task and can easily be forgotten.
Humans have a natural ability to learn quickly from well-designed feedback. If you exploit that ability in your designs, your users will appreciate it.
A long-standing design goal for iPhone apps is that they support a very specific style of interaction: users take out their device, open an app, perform a task quickly and then they’re done—either because they take an incoming call or because they pocket their device to get on with other things.
To enable this get-in-get-out interaction style, every app must have a well-defined purpose. App developers are encouraged to implement only the functionality required to perform the purpose of their apps. This development style pares down apps to keep them focused and avoids featuritis.
Posted in User Interfaces
It’s not often that I’m stopped in my tracks by a user interface element in Mac OS X, which is the reason for this post. I was using the Activity Monitor application to show which processes were consuming the most memory when I spotted HPShortcutManager, the process highlighted in the following screenshot.
Everyone prefers websites that download quickly. As a result, we’re likely to move on to other, competing websites if a website downloads slowly. For example, Nielsen’s rule of thumb is that websites should download in ten seconds or less. To reflect our desire for faster websites, and to improve our overall web user experience, Google now includes download speed in its calculation of a website’s placement in its search results; Google rewards faster websites with a higher placement. This post describes three free tools for measuring the performance of your website.
By default, Max OS X hides the
.png file extension of screenshots it saves to the desktop. However, I prefer to see the extensions of the files I’m working with. So after continually revealing the extension of every screenshot file manually, I decided to find a permanent solution.
To manually reveal the extension of a file, first select the file in the Finder and display the file’s Info window by typing command-I or by selecting Get Info from the File menu. Next, uncheck the Hide extension setting in the Name & Extension section. That’s it. If you apply this technique to a screenshot file on the desktop, Mac OS X reveals the file’s
.png extension. The following image shows the Info window for a screenshot file. The unchecked Hide extension setting is highlighted.
Posted in How To
Tagged Mac OS X
Although Quick Response (QR) codes have been around since 1994, the explosion of camera-enabled mobile devices makes QR codes a quick and easy way to grab all sorts of information, including URLs, phone numbers, email addresses and text. For example, the image on the left is the QR code for the Usability, etc. website. Reading this code with a mobile device opens Usability, etc. in the device’s web browser.