Functional decomposition is a process used by engineers and designers for identifying functions in various design tasks. The concepts of function and functional decomposition are important in engineering to understand for converting complex problems into abstractions.

However, research results indicate that engineers and designers struggle to apply functional decomposition methods during design tasks, such as product dissection, due to the abstract nature of product functions. Augmented reality, coupled with tangible objects, provides a platform on which information about different design aspect models can be blended and presented to the user during a product dissection or other design task. Past research discusses the interrelations between function, behavior and structure, and explains how providing information on one area contributes to understanding in the other areas.

This research develops an AR application to overlay context-sensitive information about product behavior and structure during a product design task, a product dissection, to contribute to users’ understanding of function. A user study was conducted to evaluate the

effectiveness of this AR-supported product dissection. Participants were asked to dissect a hair dryer and toy dart blaster and generate a function diagram for each to describe how they work: one dissection using the AR application and the other a physical dissection, to serve as a baseline. Function diagrams allow for comparison of user’s functional understanding. The function diagrams were evaluated for accuracy on several metrics including the total number of functions generated and the number of syntactical, semantic and relational errors present in each diagram. While no statistical or qualitative differences were found between the diagrams generated during the AR-supported and non-AR supported tasks, from study of the users’ function diagram and pre- and post-study test scores, several observations were made and trends were noted about users’ understanding of function and their difficulty in applying different aspects of functional decomposition.