Reimagining a User Interface, Part 1
One of the first steps in reimagining a user interface design is to search for opportunities to reduce the number of actions that a user needs to take in the app. What steps can be simplified? What actions can safely be eliminated? The pool length selection screen in the new Swim+ app presents a simple case study examining these choices.
There are only a limited number of pool sizes used in competitive swimming and recreational lap swimming: 25 yards, 25 meters, and 50 meters. These are referred to as short course yards for 25 yard pools, short course meters for 25 meter pools, and long course for 50 meter pools. On occasion you might find a 20 yard or 20 meter pool at a gym or hotel. Also, many swimmers simply swim in open water lakes, rivers, or the ocean outside of a pool. But, the key observation is that there are a limited number of possible pool sizes to pick from when initiating a lap swim workout.
The Apple Watch workout app pool length selection screen provides a flexible interface capable of configuring any type of pool length in either English or metric units. This flexibility comes at a price: it takes substantial time to configure one of the standard pool sizes. Consider the effort required to switch from a 25 yard pool to a 50 meter pool. First, you need to change the units from English to metric, which takes one button press to display the change units screen, a second button press to select the metric units and return to the main pool length screen. Then, a user needs to select the stepper control increment button 25 times to change the pool length from 25 to 50. The total button tap gestures to change the workout pool length is 27 taps. One additional tap is required to start the workout bringing the total to 28 gestures to select a pool length and start a workout. It’s a slow and tedious set of actions that seems ripe for improvement.
Apple Watch Workout app pool length selection screen
The first attempt to reimagine this design used a four button design. Each button allowed the user to select a specific pool length. The version designed for the United States offered 20 yard, 25 yard, 50 yard, and open water options. The central problem with this approach is that swimmers might encounter more than four pool lengths in standard use: missing from this list are 20 meter, and 25 meter lengths. 25 meter pools are quite common because the official olympic sized pools are 25 meters by 50 meters so that you can swim either long course 50 meter laps, or short course meters 25 meter laps.
But, this design has a significant strength: it takes only one button tap gesture to select the desired pool length and start a workout! This design reduces the number of button taps by an incredible 96%.
Original Swim+ pool length selection screen design
Despite the convenience of the four button design, a design that allows swimmers to pick from any of the five standard pool lengths would provide users with greater flexibility. But, it would be critical to find an approach that would still minimize the number of gestures required to select a pool length and start a workout. One option would be to use a design using a table view with the standard pool lengths as options. The problem with this design option is that the Apple Watch only shows four table view rows without scrolling. A user would not be able to initially see all the options they could select, which makes it slightly more challenging for users to learn the interface. But, it would only take two gestures to select a pool length and start a workout.
Another option would be to replace the stepper control from the Apple Workout app design with a picker control limited to only allow for the standard five pool lengths and an option for open water swimming. This design presents a reasonable compromise between the four-button or table view designs and the stepper design of the Apple Workout app. The picker design requires three gestures to pick a pool length and start a workout: one tap on the picker to activate the picker, a swipe to the correct pool length, and then a final button tap to select the pool length. This design reduces the number of gestures by 89% from the design of the Apple Workout app.
Final Swim+ pool length selection screen design
Thinking critically about each action that someone must perform to work with a user interface is a key step in improving and optimizing a user interface. Most user interface designs present opportunities for redesign that can reduce the number of actions required to use the software, and a chance to improve the functionality of the design.