GazePlotter
Documentation Chapters

AOI Comparison

AOI Comparison in GazePlotter provides quantitative analysis of eye-tracking data through bar charts. It aggregates gaze metrics across Areas of Interest (AOIs) for statistical comparison and analysis.

AOI Comparison showing aggregated AOI metrics for a selected stimulus.

Interested on how to operate with plots in general within the workspace? See:

Metric Contract

To render an AOI Comparison plot, GazePlotter queries the workspace’s metric library. This visualization requires a metric configuration that satisfies the following contract:

  • Output Shape: aoi-vector (computes a value or distribution for each Area of Interest individually).
  • Windowing: forbidden (calculated across the selected time range as a single aggregate).

Metrics Documentation: For details on how these raw metrics are calculated, see Fixation & Dwell Durations and Gaze Counts & Latency.

Configuration via Settings Pane

Clicking the AOI Comparison plot card in the workspace selects the plot and opens its configuration options in the sidebar Settings Pane (or bottom sheet on mobile). The settings are organized into the following collapsible sections:

Stimulus

Choose the stimulus to analyze. Each stimulus contains its own set of Areas of Interest (AOIs) which will be displayed as bars in the chart.

  • Edit stimulus library…: Opens the Stimuli Modification modal to manage stimulus files and dimensions.

Participant group

Filter the eye-tracking data by group or individual participant.

  • Select group: A dropdown containing All participants and any custom participant groups defined.
  • Edit groups…: Opens the Participant Groups modal to create or modify comparative groups.
  • Edit participants…: Opens the Participant Modification modal to customize participant properties and metadata.

Metric

Configure the quantitative metric displayed on the value axis.

  • Select metric: A dropdown of all metric instances in the library that satisfy the aoi-vector shape contract. Standard metrics include:
    • Time on AOI (absoluteTime): Total duration spent looking within the boundary (see Durations).
    • Relative time on AOI (relativeTime): Proportion of total time spent in each AOI (see Durations).
    • Visit count per AOI (visitCount): Number of distinct entries into the boundary (see Counts & Latency).
    • Visit duration (visitDuration): Average duration of visits (consecutive fixations) (see Durations).
    • Fixation count per AOI (fixationCount): Number of fixations within the boundary (see Counts & Latency).
    • Average fixation duration (fixationDuration): Mean length of individual fixations (see Durations).
    • Time to first fixation (timeToFirstFixation): Average latency until initial entry (see Counts & Latency).
    • First fixation duration (firstFixationDuration): Mean length of the first fixation (see Durations).
  • Edit metric library…: Opens the Metric Library modal where you can customize parameters or define entirely new custom metrics to calculate across the AOIs.

Visualisation

Configure the visual layout and rendering options for the bar chart.

  • Statistical overlay: Render statistical summaries over the raw data bars:
    • None: Shows only the mean bars.
    • Mean ± 95% CI: Draws error bars showing the 95% Confidence Interval.
    • Mean ± SD: Draws error bars showing the Standard Deviation.
    • Boxplot: Overlays a standard box-and-whisker plot mapping the quartile distribution.
  • Orientation: Select Horizontal (default) or Vertical bar layout.
  • Order by: Sort bars by Value or by AOI order.
  • Direction: Sort bars ascending (ASC) or descending (DESC).
  • Scale range: Explicitly set the value axis minimum and maximum (0 = Auto).
  • Hide data: Check No AOI data to hide participants who have zero registered fixations/events across all AOIs.

Time range [ms]

Filter the temporal range from which fixations and saccades are fetched.

  • Start: Limit the minimum time boundary (ms).
  • End (0 = Auto): Limit the maximum time boundary (ms) or leave at 0 for automatic duration matching.

Areas of Interest

Filters which Areas of Interest (AOIs) are rendered in the bar chart.

  • Configure AOI Library…: Opens the AOI Modification modal to add, remove, rename, or color-code AOIs.

Export

Located at the bottom of the Settings Pane:

  • Download plot…: Opens the export modal to download the bar plot.
    • File formats: PNG (transparent background) or JPG (white background).
    • Dimensions: Customizable width (height maintains a 5:3 aspect ratio).
    • Quality: Adjustable DPI setting.
    • Margins: Configurable top, right, bottom, left margins.
    • Preview: Live render of the output before saving.
  • Export Data: To export raw statistical values in CSV format for R, Python, SPSS, or other analytical software, see the Aggregated Data Export documentation.

Interpretation

Use AOI Comparison to:

  • Compare AOI performance: Identify which areas attract most/least attention.
  • Quantify differences: Obtain precise measurements rather than visual estimates.
  • Perform group comparisons: Analyze how different participant groups behave comparative to each other.
  • Conduct statistical analysis: Export exact computed metric values per participant for further processing.