Round Smartwatch Interactions


Jan 2016 – May 2016, 4 member team project



Dr. Thad Starner



  • Surveys
  • UI Design
  • User Testing




With the growing availability of smartwatches, the number of round smartwatches available in the market has also increased. But unfortunately most of the current user interfaces for round smartwatches are still based on standard rectangular interfaces. Accommodating these standard rectangular interfaces to a round touchscreen without losing content comes with a loss of precious screen estate. To solve this problem particularly for list interfaces, we propose Circular Scroll.




Round user interfaces have been rather uncommon on mobile devices. Although vendors equip user interface and interaction designers with style guides for the new platforms, e.g. the Android design guidelines, it seems existing user interfaces were almost exclusively developed with rectangular touchscreens in mind. An example of this is the standard Android list interface depicted in the figure below.

Since list selection is one key use case for smartwatches, and small touchscreens are likely to slow down interaction times for list selection tasks, list selection is one of the applications most needing adjustments for small round interfaces.

The majority of Wear devices have round displays, which have 22% less UI space than rectangular displays.

Material Design Guidelines

Android Wear


In order to better understand the landscape of round smartwatch usage, the team decided to send out a survey to round smartwatch users. This survey particularly asked the respondents what did they use their smartwatch for and what was the context of such smartwatch usage. Basic demographic data and the model of the watch were also asked for in the survey.

The survey was attempted by 30 respondents. The responses were analyzed to reach to the following conclusion about the tasks performed by smartwatch users and their contexts:

TASKS: A significant majority of smartwatch users use their watches for tracking their physical activity and viewing notifications and reminders. A very small proportion of people used the watches to respond to messages and for controlling music.

CONTEXT: The most common contexts in which people used a smartwatch to control their music included situations when they were mobile. Ex: working out, walking, driving, etc.


In order to understand the reason behind infrequent usage of smartwatch music apps, the team decided to do a competitive analysis of the existing smartwatch music apps in the market. The team looked at a wide range of music apps for Android wear, Apple watch as well and the Pebble watch.

A thorough analysis of these apps helped us understand some of their major limitations which kept people from using these apps frequently.

Limitations of current smartwatch music apps:

  • Complicated swipe based navigation requiring the user to memorize/ guess where controls are.
  • High dependency on audio input for performing song search.
  • Unusual sorting and grouping making it difficult to search for specific songs.


After gaining sufficient knowledge of the smartwatch music app domain through user and market research the team decided to design a custom music app that targeted at overcoming the limitations of current music apps. To start off the design process, the team decided to conduct a few brainstorming and whiteboard session to explore and discuss different dimensions of potential solutions.


Based on the brainstorming discussion the team came up with several ideas for improving the current swipe based interaction on smartwatches. The major issue with swipe based interaction was its constrained ability to help users move across multiple screens. One single swipe let the user move from one screen to another or scroll down a few items in a long list. The three interaction styles proposed by our team were attempts to make the music app navigation more efficient and easy. These included curved scroll bars on the sides and a full circular scroll bar.


Circular Scroll consists of a ring aligned to the edge of the touchscreen and comprises of categories of list entries that can be preselected. The selected category’s items are displayed in the middle of the ring. In this project we propose Circular Scroll particularly for the content of music apps, as it is one of the most underutilized application space on smartwatches.

Design Changes

  1. Bigger (Thicker) Scroll Ring : This was done to facilitate easy selection of the categories/ alphabets listed in the ring.
  2. Center Aligned Text :  The text was aligned to the center of the screen to avoid cutting off edges.
  3. Album names removed to reduce the clutter on the screen.


We compare the three techniques for two different list sizes, resulting in a 3 * 2 factorial within subject design.

Independent Variables

  1. Selection Technique : Linear scroll, Circular + Linear scroll, Circular + Circular scroll
  2. List Sizes :  Small (30 items), Large (100 items)


  1. Circular + Linear scroll yields faster selection for small lists.
  2. Circular + Circular scroll yields faster selection in large lists.


  • 12 participants (3 female)
  • Average age : 25
  • 1 participant was left handed
  • All had experience using touch screens but not necessarily smartwatches


After the participant put the watch on and played with the interfaces for a while, they were dictated 7 item selection tasks to be done using each of the three selection techniques and on both the lists. The time on each task was recorded and the participant was asked to rate the experience on a NASA TLX scale for each technique.


Circular + Linear scroll resulted in the least amount of task completion time for small lists. The average task completion time using Circular + Linear scroll was about 72% less than that of Linear scroll. The linear and Circular + circular scroll had about the same average task completion time.

Circular + Circular scroll drastically outperformed the other two techniques. It was around 88% faster than linear scroll and 68% faster than Circular + Linear scroll.