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Memory Tracer & Memory Compass

Design Implementation

Prototyping Process of Memory Tracer


We initially envisioned the form for the Memory Tracer to trace moments in a miniature sandbox that were drawn daily and represented the total path that the user had taken on that ‘day in history’. Although the traces could be precisely tied to today’s date and drawn to a relative scale, they remained unintelligible; there was not enough context to trigger experiences of reminiscence. We shifted to using a 16x16 LED matrix as the primary visual output for Memory Tracer. Compared to the low-resolution output of the Sand Tracer, an LED matrix was easier to work with and provided a higher resolution, while lending itself to be integrated into a variety of enclosures. We diverted from the explicit ‘trace’ of a path traveled and designed an animation akin to an hourglass, that progressively became more saturated until the display was entirely full, at which the moment is revealed.

Through living with the Hourglass prototype, we found a moment being surfaced in the background was delightful. Yet we found the overall experience underwhelming. The device was only showing a countdown to when a moment would be revealed in the future. The temporal expression shown while a moment surfaced had been reduced to a form of clock time, that had no correlation with the location history data. The capacity to support pre-interaction and prime everyday reminiscence was lacking. After various experiments, we ultimately decided to make the focal point of Memory Tracer’s interface a map of the moment. As the moment is surfaced, the display slowly shows more of the map. This gradually traced map, paired with slowly revealed contextual clues (that can be accessed if desired) provided enough context for Memory Tracer to remain intriguing, to trigger anticipation, and to support experiences of everyday reminiscence while the moment is being revealed.

Prototyping Process of Memory Campus


White, J., Odom, W., Brand, N., Zhong, C. Memory Tracer & Memory Compass: Investigating Personal Location Histories as a Design Material for Everyday Reminiscence. In Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems.

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