Frequent Pattern Mining of Eye-Tracking Records Partitioned into Cognitive Chunks

Noriyuki Matsuda,Haruhiko Takeuchi

doi:10.1155/2014/101642

Abstract

Assuming that scenes would be visually scanned by chunking information, we partitioned fixation sequences of web page viewers into chunks using isolate gaze point(s) as the delimiter. Fixations were coded in terms of the segments in a5×5mesh imposed on the screen. The identified chunks were mostly short, consisting of one or two fixations. These were analyzed with respect to the within- and between-chunk distances in the overall records and the patterns (i.e., subsequences) frequently shared among the records. Although the two types of distances were both dominated by zero- and one-block shifts, the primacy of the modal shifts was less prominent between chunks than within them. The lower primacy was compensated by the longer shifts. The patterns frequently extracted at three threshold levels were mostly simple, consisting of one or two chunks. The patterns revealed interesting properties as to segment differentiation and the directionality of the attentional shifts.

Highlights

In effect extracted chunks from partitioned sequences in their work on the importance of web page objects and their locations. They grouped consecutive fixations within each areas of interest (AOI) into a chunk called a glance to obtain plain sequences of glances coded in AOI
For the sake of simplicity, we will focus on the eye movements of web page viewers, and we will assume that the pages are divided into grid-like AOIs, that the fixations are coded in terms of the areas in which they fall, and that chunks are delimited by isolate gaze points
Eye-tracking researchers have inferred a fixation from gaze points closely clustered in space and time, treating it as a meaningful unit of information processing, that is, a chunk, a familiar concept in psychology

Summary

Introduction

In viewing natural scenes or displays, a chunk continues to grow until interrupted by one or more isolate gaze points resulting from drifting attention or by accident These do not participate in any fixation. In effect extracted chunks from partitioned sequences in their work on the importance of web page objects and their locations They grouped consecutive fixations within each AOI into a chunk called a glance to obtain plain sequences of glances coded in AOI. For the sake of simplicity, we will focus on the eye movements of web page viewers, and we will assume that the pages are divided into grid-like AOIs, that the fixations are coded in terms of the areas in which they fall, and that chunks are delimited by isolate gaze points. The present approach is expected to advance eye-tracking research along with conventional heat maps, scan paths, and network analysis recently developed by Matsuda and Takeuchi [8,9,10]

Method

Results

B3 B4 C5

Discussion