ETAnalysis Manual EYE TRACKING DATA ANALYSIS TOOL MANUAL VERSION 4.1 July 2022 [email protected] Web site: www.argusscience.com ETANALYSIS MANUAL Table of Contents 1 INTRODUCTION ............................................................................................................................................... 5 1.1 BASIC FEATURES ........................................................................................................................................... 5 1.2 OPTIONAL FEATURE – STIMULUS TRACKING................................................................................................ 6 2 PROJECT STRUCTURE ................................................................................................................................... 7 3 PROJECT MANAGEMENT ............................................................................................................................. 9 3.1 PROJECT SIZE ............................................................................................................................................... 9 3.2 EXACT UPDATE RATE ................................................................................................................................... 9 3.3 SAVING AND BACKING UP PROJECTS .......................................................................................................... 10 3.4 DATA, BACKGROUND IMAGE AND VIDEO FILE STORAGE ......................................................................... 11 3.5 COPYING A PROJECT TO A DIFFERENT PC ................................................................................................. 11 3.6 COPYING A PROJECT TO A DIFFERENT LOCATION ON THE SAME PC ........................................................ 13 4 USER INTERFACE AND CREATING A PROJECT ................................................................................... 15 4.1 CREATING OR OPENING A PROJECT ........................................................................................................... 15 4.2 MENU BAR ITEMS ....................................................................................................................................... 19 4.2.1 File Menu ............................................................................................................................................. 19 4.2.2 Options Menu....................................................................................................................................... 19 4.2.3 Configure Menu ................................................................................................................................... 21 4.2.4 Group Menu ......................................................................................................................................... 22 4.2.5 View Menu ........................................................................................................................................... 22 4.2.6 Help Menu ........................................................................................................................................... 23 4.3 TOOLBAR BUTTONS .................................................................................................................................... 24 4.4 PROJECT TREE ............................................................................................................................................ 25 4.5 DISPLAY AREA ............................................................................................................................................ 25 5 OPENING PARTICIPANT (GAZE DATA) FILES ...................................................................................... 27 6 PARSING EVENTS .......................................................................................................................................... 29 6.1 DEFINITION OF EVENTS .............................................................................................................................. 29 6.2 EVENT START CONDITION .......................................................................................................................... 30 6.3 EVENT STOP CONDITION ............................................................................................................................. 31 6.4 PARSE BY VIDEO ......................................................................................................................................... 33 6.5 ADDITIONAL OPTIONS ................................................................................................................................. 34 7 CONFIGURE STATIC BACKGROUND IMAGES ...................................................................................... 35 7.1 USING A DEFAULT BACKGROUND IMAGE ................................................................................................... 40 7.2 IMAGES TO BE USED WITH ET3SPACE DATA .............................................................................................. 40 7.3 EXPORTING AND IMPORTING BACKGROUND CONFIGURATIONS ............................................................... 41 8 STATIC AREAS OF INTEREST .................................................................................................................... 43 8.1 DEFINING AREAS OF INTEREST GRAPHICALLY .......................................................................................... 43 8.1.1 Draw rectangular areas ....................................................................................................................... 44 8.1.2 Draw Polygons .................................................................................................................................... 46 8.1.3 Saving AOI sets and other dialog window features ............................................................................. 48 8.2 DEFINING AREAS OF INTEREST MANUALLY ............................................................................................... 49 9 EVENT CORRESPONDENCE WITH BACKGROUND IMAGES AND AOI SETS ............................... 50 10 FIXATION AND SACCADE ANALYSIS .................................................................................................. 52 10.1 FIXATION ANALYSIS ................................................................................................................................... 52 10.1.1 Origin of fixation algorithm ................................................................................................................. 53 2 ETANALYSIS MANUAL 10.1.2 Fixation Algorithm Description ........................................................................................................... 54 10.1.3 Default Fixation Criteria ..................................................................................................................... 56 10.1.4 Creating Fixation sets .......................................................................................................................... 61 10.1.5 Fixation data display ........................................................................................................................... 62 10.1.6 Fixation overlay on data time plots ..................................................................................................... 63 10.2 SACCADE ANALYSIS .................................................................................................................................... 65 10.2.1 Creating Saccade sets .......................................................................................................................... 65 10.2.2 Saccade Detection Criteria .................................................................................................................. 66 10.2.3 Saccade Data Display .......................................................................................................................... 68 10.2.4 Saccade overlay on data time plots ..................................................................................................... 69 11 FIXATION SEQUENCE ANALYSIS WITH STATIC AOIS ................................................................... 71 11.1 FIXATION SEQUENCE DATA LIST AND INFO TAB ........................................................................................ 71 11.2 AOI SUMMARY ........................................................................................................................................... 72 11.3 TRANSITION TABLE .................................................................................................................................... 73 11.4 CONDITIONAL PROBABILITY TABLE .......................................................................................................... 73 11.5 JOINT PROBABILITY TABLE ....................................................................................................................... 74 12 DWELL ANALYSIS ..................................................................................................................................... 75 12.1 DWELL DATA LIST AND INFO TAB .............................................................................................................. 75 12.2 AOI SUMMARY (FOR DWELLS) .................................................................................................................. 76 12.3 TRANSITION TABLE (FOR DWELLS) ........................................................................................................... 76 12.4 CONDITIONAL PROBABILITY TABLE (FOR DWELLS) ................................................................................. 76 12.5 JOINT PROBABILITY TABLE (FOR DWELLS) .............................................................................................. 77 13 PUPIL DIAMETER ANALYSIS ................................................................................................................. 78 13.1 DETERMINING A PUPIL DIAMETER SCALING FACTOR ............................................................................. 78 13.2 PERFORMING A PUPIL DIAMETER ANALYSIS ............................................................................................ 78 13.3 PUPIL ANALYSIS DISPLAY .......................................................................................................................... 81 14 GRAPHICS DISPLAYS ............................................................................................................................... 82 14.1 TIME PLOTS ................................................................................................................................................ 82 14.2 TWO DIMENSIONAL PLOTS ......................................................................................................................... 86 14.2.1 Heat map, Peek map, and point-of-gaze scatter plots......................................................................... 87 14.2.2 Two Dimensional Fixation Scan Plots ................................................................................................. 90 14.3 AOI BAR PLOTS .......................................................................................................................................... 96 14.3.1 Total time in each AOI ......................................................................................................................... 97 14.3.2 Percent time in each AOI to total time ................................................................................................. 97 14.3.3 Percent time in each AOI to any AOI .................................................................................................. 97 14.3.4 Fixations in AOIs bar plots .................................................................................................................. 97 14.3.5 Average Pupil Diameter in each AOI .................................................................................................. 97 14.4 SUPERIMPOSE MOVING GAZE AND FIXATIONTRAIL OVER STATIC BACKGROUNDS ................................. 98 15 COMBINE DATA ACROSS EVENTS ..................................................................................................... 101 15.1 SWARM DISPLAY ....................................................................................................................................... 101 15.2 POOL FIXATION DATA .............................................................................................................................. 104 15.3 AVERAGE FIXATION SEQUENCE AND DWELL SUMMARIES ..................................................................... 106 16 WORKING WITH SCENE VIDEO FILES AND MOVING AREAS OF INTEREST ........................ 108 16.1 USING THE CONFIGURE VIDEO DATA DIALOG ........................................................................................ 109 16.1.1 Gaze Data Type ................................................................................................................................. 110 16.1.2 Video File........................................................................................................................................... 110 16.1.3 Sync video with Event, Segment, or File ............................................................................................ 111 16.1.4 Scale gaze data to video ..................................................................................................................... 111 16.2 SCALING DATA TO VIDEO FILES .............................................................................................................. 112 16.3 ENVIRONMENT VIDEO .............................................................................................................................. 113 3 ETANALYSIS MANUAL 16.3.1 Description and purpose .................................................................................................................... 113 16.3.2 Creating an environment video node ................................................................................................. 113 16.4 CREATING MAOIS FOR INDIVIDUAL EVENTS .......................................................................................... 114 16.5 USING AN ENVIRONMENT VIDEO TO AUTOMATE MAOI CREATION ....................................................... 114 16.6 SHARING MAOIS, WITH MULTIPLE SEGMENTS OR EVENTS .................................................................... 114 16.7 CREATING MOVING AREAS OF INTEREST ................................................................................................ 116 16.7.1 Drawing Areas of Interest in Videos .................................................................................................. 118 16.7.2 Adjusting AOIs Throughout Video ..................................................................................................... 120 16.7.3 “Auto Detect” MAOIs ....................................................................................................................... 123 16.7.4 Use Environment video to Auto Detect MAOIs for multiple events ................................................... 125 16.7.5 “Auto Associate” MAOIs ................................................................................................................... 126 16.7.6 Auto Convert LAOIs to MAOIs .......................................................................................................... 127 16.8 FIXATION SEQUENCE AND DWELL ANALYSIS WITH MOVING AOIS (MAOIS) ....................................... 128 16.8.1 Applying Fixations Computed with Respect to Scene Image Coordinate Frame to MAOIs .............. 128 16.8.2 Calculating Fixations with Respect to MAOIs ................................................................................... 131 16.9 PLAYING THE SCENE VIDEO WITH SUPERIMPOSED GAZE TRAIL AND OTHER INFORMATION ................ 133 16.10 SWARM VIDEO WITH SHARED STIMULUS VIDEOS AND MAOIS ............................................................... 136 16.10.1 Swarm Video over Shared Video ................................................................................................... 136 16.10.2 Swarm Video over Moving AOIs .................................................................................................... 137 17 STIMULUS TRACKING FEATURE (REQUIRES ST LICENSE) ......................................................... 139 17.1 CORNER MARKERS ................................................................................................................................... 139 17.2 MAKING A DISPLAY RECORDING .............................................................................................................. 140 17.3 TRACK MONITOR ...................................................................................................................................... 141 17.3.1 Initiate automatic Monitor Tracking from an event node .................................................................. 141 17.3.2 Initiate auto Monitor Tracking from a Segment node ........................................................................ 143 17.3.3 View or Edit Monitor Tracking results in Scene Video ...................................................................... 144 17.3.4 Alternate auto Monitor Tracking method .......................................................................................... 145 17.4 PARSE SEGMENT INTO MULTIPLE EVENTS IF APPROPRIATE ................................................................... 147 17.5 IMPORT AND CONFIGURE STIMULUS IMAGES AND/OR RECORDINGS ...................................................... 147 17.5.1 Add Stimulus Files to project ............................................................................................................. 147 17.5.2 For each event, Configure Stimulus to specify the boundary of the image with respect to the tracked boundary of the monitor .................................................................................................................................... 149 17.6 CONFIGURE AREAS OF INTEREST IN STIMULUS FILES ............................................................................. 152 17.7 ANALYZE RESULTS ................................................................................................................................... 153 17.7.1 Compute Fixation, Fixation Sequence and Dwell statistics ............................................................... 153 17.7.2 View Gaze, Fixations, and Fixation Sequence Statistics, over Stimulus ............................................ 153 18 ADDITIONAL FEATURES ....................................................................................................................... 155 18.1 COPY PROJECT SETTINGS FROM ANOTHER PROJECT ............................................................................ 155 18.2 EXPORT DATA............................................................................................................................................ 156 18.3 SAVE IMAGES AND VIDEO DISPLAYS ........................................................................................................ 158 18.4 DO ALL CALCULATIONS ........................................................................................................................... 158 18.5 CHECK FOR UPDATES ............................................................................................................................... 158 18.6 LIVE AOI BAR PLOTS ............................................................................................................................... 158 18.6.1 LAOI Bar Plot for single event .......................................................................................................... 158 18.6.2 LAOI Bar Plot for multiple events ..................................................................................................... 160 4 ETANALYSIS MANUAL 1 Introduction 1.1 Basic Features Argus Science ETAnalysis is designed to help process and analyze data collected with eye trackers made by Argus Science, and some eye trackers formerly manufactured by Applied Science Laboratories (ASL). It can be used to: • examine and plot raw data; • associate scene images with sections of gaze data; • define areas of interest on images; • associate videos with sections of gaze data; • define moving areas of interest on videos; • reduce gaze data to fixations; • reduce gaze data to “dwells” (periods of continuous gaze on one area of interest); • detect saccades between identified fixations and compute saccade parameters; • display data graphically; • time plots; • X/Y scan plots superimposed on scene image; • heat map plots on scene image; • compute various statistics that relate fixations or dwells to areas of interest and produce corresponding bar plots; • combine results across trials or subjects by averaging statistical data from each, or by pooling the original data; • create swarm display showing gaze from multiple trials or subjects overlaid on a single background or video; • export results in Excel or ASCII text format for further custom analyses. The Argus ETAnalysis application is project based. A project includes multiple data files, scene video files (if applicable), stimulus files (backgrounds and/or videos presented to participants) and all of the computations requested by the user. The project is organized by sections of data called “events”, defined by start and end conditions specified by the user. A tree diagram, in the left panel of the main program window, shows the project hierarchy, and a context menu available by right clicking each node lists all operations that can be performed on that node and its sub-nodes. Argus ETAnalysis can analyze “.csv” file data recorded by ETVision, ETMobile or ASL Mobile Eye, “.eyd” data recorded by ETVision, ETSever and ASL EyeTrac products, and “.ehd” data recorded by Argus or ASL products using the ET3Space or ASL EyeHead Integration feature. 5 ETANALYSIS MANUAL 1.2 Optional Feature – Stimulus Tracking Stimulus Tracking (“StimTrack” or ST) is an optional feature that can greatly enhance analysis capabilities when a head mounted eye tracker has been used to record gaze with respect to a head mounted scene camera (when there is no external head tracker and ET3Space cannot be used). Automated analysis of this type of data is traditionally difficult because objects that are stationary in the environment are moving images on the head mounted scene camera. The digital data specifies point of gaze on the scene camera field of view, but not with respect objects or surfaces in the environment. Stimulus Tracking allows users of a head-mounted eye tracker with only a head mounted scene camera (no external head tracker) to analyze data of participants looking at a computer monitor as efficiently as if the data came from a stationary (table mounted) eye tracker. Stimulus Tracking can be used to: • define backgrounds or videos associated with participant trials, • define screen capture videos recorded with participant data sessions, • define areas of interest within these stimulus backgrounds or videos to share across multiple subjects or trials, • automatically track the computer monitor through a participant’s scene video, • analyze gaze within the scene monitor and within areas of interest defined in stimuli, • create swarm display showing gaze from multiple trials or subjects overlaid on a single background or video that was presented on the computer monitor, • perform all the options listed in the previous section to view, combine, and export gaze results. 6 ETANALYSIS MANUAL 2 Project structure The project structure is represented by a tree diagram on the main program window left panel. “Nodes” are added to the tree as data and analysis results are added to the project. Each node “holds” a section of data or analysis computation result. At the top level of the tree is a node called “Data Files”, with sub-nodes that are the original data files recorded by the eye tracker. When data is recorded by some Argus (and some ASL) eye trackers the user can start and pause recording on a single file as many times as desired. Data files are therefore divided into “segments” of continuous data (between each record and pause). In ETAnalysis, these data file “segments” form sub-nodes under the data file node. A file may have only one segment or multiple segments. (“.csv” type files, used by some eyetracker models, always include only a single segment). Note that the number of segments in a data file is not determined by ETAnalysis, but rather was determined as the data was recorded. ETAnalysis can further sub-divide each data segment into “events” defined by some beginning and end criteria, and these “events” form sub-nodes under the each segment node. Each segment must have at least one event sub-node. The default event is the entire segment, but the user may specify criteria to divide a segment into multiple events. If the data is part of an experiment design, events usually correspond to experiment “trials”. The data file, segment, and event nodes all represent sections of originally recorded data. Sub-nodes under each event are all created by data processing in ETAnalysis program. Gaze Data in an event can be reduced to a set of fixations, forming a sub-node under the event. Fixation sets can be further processed to match fixations with “areas of interest” on the scene, forming “fixation sequence” and “dwell” nodes under the fixation node. Various statistics can be computed from the fixation sequence and dwell data to form additional sub-nodes. In the example shown at left, the project contains two files, “Peter_1.eyd”, and “Andrea-1.eyd”. Only one data segment was recorded on each file, but each segment has been divided, by ETAnalysis, into 2 events. Fixations sets as well as Fixation Sequence and Dwell statistics have been computed for all events. To examine effects across different events (or trials), it is necessary to combine data from some of the nodes that are at the ends of these tree branches. Data gathered from multiple fixation nodes are grouped under a top-level node called “Pooled Fixation Data”. Data gathered from groups of statistics nodes (the very ends of the Data File node branches) are grouped under another top-level node called “Summary Averages”. 7 ETANALYSIS MANUAL A right arrow symbol ( ) at a node (see “Summary Averages” node, or “Fixations” nodes on the tree diagram example) indicates that there are sub-nodes below it which can be expanded (made visible) by left clicking on the right arrow symbol. After expanding, the arrow symbol on the node will point diagonally towards lower right ( ). This symbol can be clicked to collapse the node. Right clicking on any node brings up a context menu with a list of operations that can be performed on data in that node. Almost all nodes have a data display in the right panel of the main ETAnalysis window, which shows a listing of the data at that node. In each case there is also a “More Info” tab on the right panel, which provides various additional information about the contents of the node. The highest-level nodes (“Participant Files”, “Pooled Fixation Data”, and “Summary Averages”) are the only exceptions. These contain no data, but only serve to define the category of data in their branches. ETAnalysis can analyze data from csv data files, eyd data files, and ehd data files recorded from Argus Science and ASL eye tracker products. A single project, however, is intended to include files of a single type. These may be csv, eyd, or ehd. 8 ETANALYSIS MANUAL 3 Project Management 3.1 Project Size While there is no set maximum number of events or files, as more events and files are added to a project it will become progressively more difficult to “see” the whole project on the tree diagram, and the program may begin to perform some operations more slowly. To the extent that experiment design allows, it is generally better to divide work into multiple small projects rather than one very large project. Note that different projects can be used to perform different tasks using the same data. 3.2 Exact Update Rate The Argus ETVision system has an exact update rate that is the same as its nominal update rate of 180 Hz. Other system models have exact update rates that may differ slightly from the nominal update rate listed on the data file header. The exact update rate is determined by the eye camera, and although very close to the nominal value, is often not precisely the nominal value. For example “60 Hz” analog cameras often have update rates of 59.94 Hz. The various eye tracker models have used different cameras over the years and the exact update rate can differ slightly depending the model and version of the device used to gather data. Selecting “Exact Update Rate” from the “Configure” menu, in Argus ETAnalysis brings up an “Exact Update Rate” dialog. The dialog is a table associating an exact update rate with each possible nominal update rate. 9 ETANALYSIS MANUAL The dialog allows an exact update rate to be associated with the nominal update rate on the data file header. Time values will be reported according to these exact update rate values. Note that the values on this table apply to the entire project and cannot be specified individually for each data file in the project. Since older eye tracker models used different cameras over the years, the exact update rate can differ slightly depending the model and version of the device used to gather data. Exact update rate for any system can be determined by recording data for a timed period, or better yet, placing two marks on the data separated by a timed interval, and examining the data file to see how many fields were recorded between the marks. Update rate is the number fields divided by the time period (measured in seconds). The longer the period, the more accurate this will be. The chart below lists exact update rate values for recent versions of several eye tracker models in samples per second (Hz). If it is important that absolute time values remain precise, especially over long data segments, refer to the following list or measure as described above to find the “exact update rate” for the specific system used. System type Nominal update rate Exact update rate (Hz) (Hz) Argus ETVision 180 180 Argus ETMobile, ASL Mobile Eye 30 29.94 Argus ETMobile, ASL Mobile Eye 60 59.974 Argus ETServer; ASL EyeTrac 6, 7 60 59.94 Argus ETServer; ASL EyeTrac 6, 7 120 119.65 Argus ETServer; ASL EyeTrac 6, 7 240 240.215 Argus ETServer; ASL EyeTrac 6, 7 360 361.69 3.3 Saving and Backing up projects In addition to automatically saving the current project before closing, the program will automatically save the current project at regular intervals. The user can also manually save the project to the same path and name by selecting File→Save Project, or to a different path and file name by selecting File→Save Project As. Note that when the program saves automatically, or if File→Save Project is selected, it always saves to the same file name, and if this file becomes corrupted it is still possible to lose work. 1 0