You Know the Drill, Or do You? Investigating the Application of Mixed Fidelity Mixed Reality Prototypes in User-Feedback Activities

Abstract

User-feedback prototypes are crucial for validating design concepts, but their high cost in time and resources can hinder product development. This thesis explores the potential of Mixed Reality (MR) to address this challenge. MR, blending virtual and physical elements, offers designers greater control over a user’s perception of a design. By combining the tangibility of physical models with the flexibility and low-cost/high-fidelity visuals of virtual representations, MR prototypes promise lower costs and increased perceived fidelity. However, the effects and optimal combinations of virtual and physical features and fidelity in MR prototypes for user evaluation remain largely unexplored.

This thesis investigates this gap, beginning with a literature review examining prototyping, MR, and human perception. A novel taxonomy of MR prototype fidelity is proposed, providing a framework for discussing and specifying MR prototype characteristics. This provides a structure that informs the development and conduction of two subsequent qualitative studies. The first of these studies explores the impact of mass and virtual/physical size on user perception, using an exemplar MR prototype of a cordless electric drill. This study reveals that virtual aspects often dominate user perception, while appropriate prototype mass is required to maintain realism. This suggests the potential for high-fidelity MR prototypes with low-fidelity physical components.

A broader, second study then evaluates the influence of other MR prototype fidelity levels and features, with feedback from professional designers highlighting and directing the potential practical applications of MR prototypes. The results of this confirm the hypothesised value of MR for user-feedback prototyping activities with the designers highlighting the potential of lower cost, high perceived fidelity, and the ability to represent interactions, environments, and tasks.

The thesis concludes by discussing the findings and presenting a design support tool to empower designers in specifying and creating effective MR prototypes to suit their needs. Additionally, insights based on the author’s MR prototype development offer further practical insights and recommendations for future designers.

The most impactful findings of this work include the validation of mixing fidelity within MR, to create high value prototypes that can be created faster and cheaper, and offer improved flexibility and realism. dditionally, the linking between MR prototype implementation and prototype purpose developed in the later chapters provides direction and insight to future designers.

Date of Award	9 Dec 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Ben J Hicks (Supervisor) & James A Gopsill (Supervisor)