Human Factors Influencing Visual Statistical Inference

• Activity Number: 79
• Type: Contributed
• Date/Time: Sunday, August 3, 2014 : 4:00 PM to 5:50 PM
• Sponsor: Section on Statistical Graphics
• Author(s): Mahbubul Majumder*+ and Heike Hofmann and Dianne Cook
• Companies: University of Nebraska at Omaha and Iowa State University and Iowa State University
• Keywords: statistical graphics ; non-parametric test ; cognitive psychology ; data visualization ; exploratory data analysis ; visual analytics

Abstract

Visual statistical inference is a way to determine significance of patterns found while exploring data. It is dependent on the evaluation of a lineup, of a data plot among a sample of null plots, by human observers. Each individual is different in their cognitive psychology and judiciousness, which can affect the visual inference. The estimate of power of a lineup or a visual test can be controlled by combining evaluations from multiple observers. Factors that may also affect the power of visual inference are the observers' demographics, visual skills, and experience, the sample of null plots taken from the null distribution, the position of the data plot in the lineup, and the signal strength in the data. This paper examines these factors. Results from multiple visual inference studies using Amazon's Mechanical Turk are examined and the experiments suggest that individual skills vary substantially, but demographics do not have a huge effect on performance. There is evidence that a learning effect exists but only in that observers get faster with repeated evaluations, but not more often correct. The placement of data plot in the lineup does not affect the inference.