Solving Usability Issues through
User Interface Redesign - Philips SleepMapper
This case study details a human factors redesign project aimed at improving the usability of the Philips SleepMapper, companion app of the Philips wake-up light. Through usability testing, theoretical analysis, and heuristic evaluations, a feasible solution was found to enhance the usability of the alarm and light settings.
Background
Inspired by the sunrise, Philips created a wake-up light which wakes its users gradually by mimicking a sunrise, with a dim orange glow transitioning to a brighter yellow hue. This can be accompanied by a sound alarm which plays once maximum brightness is reached. Users can customize alarms and sunrise settings using a companion app, known as the Philips SleepMapper.
Usability tests of the companion app revealed that while first time users could intuitively figure out how to set the alarm, most misunderstood or were unaware of the sunrise feature's settings, indicating a need for clearer instructions or interface adjustments.
Project Details
Individual Contribution
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Timeline: November 2021 - February 2022
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Team size: 4
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Location: Eindhoven, The Netherlands
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Usability research
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Redesigning and prototyping
Design Methodologies
Technologies Used
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Usability Testing
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Heuristic Evaluation
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Human-centered Design
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Microsoft Teams (screen recording)
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Sketch
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MS Office
Usability Study
Participants were chosen to be first-time users of the system. Two tasks were given to do on the app using the think aloud method. The tasks involved setting an alarm and the sunrise duration of the wake-up light. They were assured that there are no wrong ways to do the task, and were asked to share out loud what they thought would be the functionality of the sunrise feature.
Analysis
Users encountered confusion regarding the sunrise duration setting, unsure if it dictates the period from start to maximum intensity or the period before the set alarm time. Some of the participants did not discover the setting or forgot about it, and missed adjusting it in the second task. This ambiguity led to inefficiency in testing due to the minimum 5-minute duration requirement.
The problems encountered in the usability study can be classified as issues of knowability of the system and clarity of elements. Three main issues were identified:
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Hidden Navigation: The sunrise duration control is concealed within the "Sun Theme" menu, posing challenges in conceptual clarity and increasing interaction costs for users.
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Mismatched Expectations: Users struggle to understand when the light will increase and reach maximum brightness, leading to confusion with common alarm usage patterns.
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Lack of Feedback: Insufficient information regarding light activation time contributes to usability issues and incorrect user expectations.
Suggested Improvements
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Add explanations or tooltips for key functions, such as the sunrise duration slider, to enhance clarity and usability.
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Clarify the start time and progression of the sunrise simulation to align with user expectations and improve user understanding.
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Address minor issues observed during usability tests, such as visibility of interface elements, to optimize user experience further.
Heuristic Evaluation
Solution 1:
Displaying three distinct time settings for sunrise start, end, and alarm time on the main alarm page to provide clear information. While this solution offers clarity, it introduces potential confusion for users by requiring adjustment of three different settings for each alarm setup.
Solution 2:
Moving the sunrise duration slider to the alarm category and utilize absolute time values to indicate sunrise duration, enhancing usability. However, this solution may disrupt user workflow by changing sunrise time when adjusting the alarm time.
Solution 3:
Reorganizing the alarm and sunrise duration slider, displaying absolute sunrise times alongside the slider for intuitive interaction. This solution maintains the relative duration slider while providing additional information on absolute sunrise times, offering a balanced approach between clarity and usability.
Solution 3 emerged as the most optimal choice. It scored highest in perceived ease of use and aesthetics while maintaining a reasonable implementation cost. By allowing users to view both relative and absolute sunrise times simultaneously, Solution 3 enhanced user understanding without disrupting workflow. Thus, it effectively addressed the identified usability issues and promoted overall user satisfaction with the Philips SleepMapper app.
