Using multidimensional scaling to quantify similarity in visual search and beyond

Michael C. Hout, Hayward J. Godwin, Gemma Fitzsimmons, Arryn Robbins, Tamaryn Menneer, Stephen Goldinger

Research output: Contribution to journalReview articlepeer-review

33 Scopus citations


Visual search is one of the most widely studied topics in vision science, both as an independent topic of interest, and as a tool for studying attention and visual cognition. A wide literature exists that seeks to understand how people find things under varying conditions of difficulty and complexity, and in situations ranging from the mundane (e.g., looking for one’s keys) to those with significant societal importance (e.g., baggage or medical screening). A primary determinant of the ease and probability of success during search are the similarity relationships that exist in the search environment, such as the similarity between the background and the target, or the likeness of the non-targets to one another. A sense of similarity is often intuitive, but it is seldom quantified directly. This presents a problem in that similarity relationships are imprecisely specified, limiting the capacity of the researcher to examine adequately their influence. In this article, we present a novel approach to overcoming this problem that combines multi-dimensional scaling (MDS) analyses with behavioral and eye-tracking measurements. We propose a method whereby MDS can be repurposed to successfully quantify the similarity of experimental stimuli, thereby opening up theoretical questions in visual search and attention that cannot currently be addressed. These quantifications, in conjunction with behavioral and oculomotor measures, allow for critical observations about how similarity affects performance, information selection, and information processing. We provide a demonstration and tutorial of the approach, identify documented examples of its use, discuss how complementary computer vision methods could also be adopted, and close with a discussion of potential avenues for future application of this technique.

Original languageEnglish (US)
Pages (from-to)3-20
Number of pages18
JournalAttention, Perception, and Psychophysics
Issue number1
StatePublished - Jan 1 2016


  • Eye-movements
  • Methods
  • Multi-dimensional scaling
  • Similarity
  • Visual search

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Language and Linguistics
  • Sensory Systems
  • Linguistics and Language


Dive into the research topics of 'Using multidimensional scaling to quantify similarity in visual search and beyond'. Together they form a unique fingerprint.

Cite this