Whose Walkability?: Challenges in Algorithmically Measuring Subjective Experience

The Walk Score is a patented algorithm for measuring the walkability of a given geographic area. In addition to its use in real estate, the accompanying API is used in a range of research in public health and urban development. This study explores how neighborhood residents differently understand the notion of walkability as well as the extent to which their personal definitions of neighborhood walkability are reflected in the Walk Score's underlying algorithm. We find that, while the Walk Score generally aligns with residents' priorities around walkability, significant subjective aspects that influence walking behavior are not reflected in the score, raising the need to consider implications for using algorithmic tools like the Walk Score in certain research contexts. We discuss the challenge of measuring subjective experience and how designers might begin to address it. We call for qualitative evaluations of algorithmic tools to help determine appropriate contexts of use.