Usability of a Digital Plate Waste Observation System for the School Lunch Study

With the development of technology, using photographs to measure plate waste is an increasing
trend. These photographs are later analyzed when the data is being entered into a form or
system. Previously, these forms or systems have not been assessed for usability. This research
study looks at three iterations of a digital plate waste observation system developed for the
School Lunch Study at Arizona State University. The System Usability Scale was used to
understand the functionality of the digital plate waste observation system. An area for free
responses was used to understand aspects of the system that were liked by research assistants
and what technical difficulties the research assistants encountered. These responses were used to
develop the next version of the digital plate waste observation system. Time to complete a task
was calculated to see the trends across all versions of the system. With each version, the System
Usability Scale scores increased along with the time to complete a task. This study found that
following the workflow of research assistants, being able to manipulate a photograph, having
menu items populated, and decreasing the amount of typing performed by adding selections to be
useful design aspects. Future digital plate waste observation systems can implement the
successful design aspects of this system, be aware of errors experienced, and implement helpful
features not found in this system. Future studies can look at the effect proctored training sessions
have on the time to complete a task and the relation of System Usability Scale scores with the
success of data entry.