The Most Frequently Offered Eye Tracking Output: Gaze Coordinates and Heat Maps

The short answer

The answer depends on which layer of output the question means. At the data level, almost every eye tracker produces gaze position: the point on a screen or scene where the person is looking, recorded as x and y coordinates with a timestamp. At the reporting level, the heat map is the output most often presented to clients and in study summaries. A heat map is a color overlay showing where attention was concentrated across one or more viewers. If the question comes from a course or quiz about eye tracking studies, the expected answer is usually heat maps. If it concerns what the hardware or software actually records, the answer is timestamped gaze coordinates.

Evidence gap: the source material for this guide contains no survey, vendor comparison or usage data that ranks eye tracking outputs by how often they are offered. The answer above rests on how eye tracking systems generally work and how their results are commonly reported. It is not based on a measured ranking.

Common eye tracking outputs and what they mean

Output | What it is | Layer

Gaze point (point of regard) | Timestamped x/y coordinates of where the eyes are directed | Raw data

Fixations | Periods when gaze stays relatively still on one location, with position and duration | Derived data

Saccades | Rapid eye movements between fixations | Derived data

Pupil size | Pupil diameter measurement, offered by many but not all systems | Raw data

Validity or confidence flags | Indicates whether each sample was tracked reliably | Raw data

Heat map | Color overlay summarizing where attention concentrated | Visualization

Gaze plot or scan path | Numbered sequence of fixations showing the order of viewing | Visualization

Areas of interest (AOI) metrics | Statistics such as time to first fixation or total dwell time within defined regions | Analysis

Raw data is captured first. Fixations and saccades are calculated from the raw gaze samples. Heat maps, gaze plots and area-of-interest metrics are built from those calculated values. This is why gaze coordinates are close to universal across systems, while particular visualizations and metrics vary between software packages.

How heat maps differ from gaze plots

A heat map shows how much attention each area received but not the order in which the areas were viewed. A gaze plot keeps the sequence and makes it possible to follow one viewer's path. Heat maps are easy to read at a glance, which is likely why they appear so often in reports. They can hide important details, such as an element that everyone looked at briefly but late in the session.

What this means if you also capture speech with a webcam

Eye tracking outputs contain no audio. Webcam-based or dedicated eye tracking records gaze data, and spoken comments are a separate stream captured by the webcam's built-in microphone or another audio input. Some study designs ask participants to think aloud while their gaze is tracked. In those studies, the useful link between the two streams is the timestamp. The audio and gaze recordings need a shared time reference so that a spoken remark can be matched to the fixation it accompanied.

• Confirm that the recording software captures audio and gaze data on the same clock or in one synchronized session.
• In the system's audio settings, select the intended microphone (the input device) before recording. Otherwise the software may default to a different mic.
• Find out whether your eye tracking software can export audio alongside gaze data or only video. This varies by product, and the source material for this guide does not document specific products.

The supplied material does not establish how built-in webcam microphones affect eye tracking accuracy, or which conferencing tools support gaze data. Check those questions against the documentation for your specific hardware and software.