Eye-Tracking Case Study

Eye Tracking Fixations

Exploring age-related and temporal patterns in eye-tracking data using statistical modelling. This case study analyzes fixation behavior using data collected at the Nemo Science Museum.

Semester

Winter 2024/2025

Institution

TU Dortmund

Focus

Statistical Modelling

Tools

R / Python / Statistics

Project Overview

Eye-tracking is a technique used to measure where and how long people focus their gaze within a visual environment. By analyzing eye movements, we can gain insights into cognition, attention, behavior, and decision-making processes.

In this case study, I used a publicly available dataset from the Nemo Science Museum in Amsterdam. Participants viewed a feature-rich image for 10 seconds while their gaze behavior was recorded. The project focuses on fixation durations and how these may differ by age and over time during the experiment.

Goals

The analysis focuses on two primary research questions:

Age and Eye Movements Do fixation durations decrease with age during childhood and increase again later in life?
Fixation Patterns Over Time Are there systematic changes in fixation durations throughout the experiment?

Data

The dataset contains recordings from more than 2,600 participants. Each participant viewed an image for a fixed duration while gaze coordinates, timestamps, pupil information, and fixation-related features were recorded or derived.Link

Data Structure

  • Pre-processed data: gaze positions, x/y coordinates, pupil size, timestamps, and experimental event messages.
  • Processed data: detected fixations with average x/y coordinates and fixation duration.
  • Demographics data: participant-level information such as gender and year of birth.

Methodology

The project used statistical analysis methods to investigate the relationship between fixation behavior, age, and temporal patterns during the viewing task. The analysis ranged from descriptive exploration to inferential modelling.

Analysis Pipeline

  1. Data preprocessing: converted raw or pre-processed gaze data into fixation-level data.
  2. Exploratory analysis: inspected distributions, missing values, age groups, and fixation durations.
  3. Statistical modelling: investigated age-related and time-dependent patterns in fixation behavior.
  4. Robustness checks: evaluated whether results remained stable under alternative processing choices.

Robustness Analysis

As an additional step, the project considered how sensitive the results were to changes in the data processing pipeline. This is important because eye-tracking results can be affected by preprocessing choices and fixation detection parameters.

  • Modified hyperparameters in the fixation detection algorithm.
  • Compared alternative processing pipelines.
  • Considered noise or missing-data scenarios to evaluate stability.

Outcome

The project strengthened my ability to work with experimental data, convert raw measurements into analysis-ready features, and apply statistical reasoning to behavioral data. It also improved my understanding of how preprocessing choices influence downstream modelling results.

Eye Tracking Fixation Data Statistical Modelling Data Preprocessing Robustness Analysis TU Dortmund

References

  • De Haas et al. (2019): Individual differences in visual salience vary along semantic dimensions.
  • Duchowski (2017): Eye Tracking Methodology: Theory and Practice.
  • Hessels et al. (2020): Task-related gaze control in human crowd navigation.
  • Holmqvist et al. (2011): Eye Tracking: A Comprehensive Guide to Methods and Measures.
  • Nuthmann et al. (2010): A computational model of fixation durations in scene viewing.
  • Salvucci & Goldberg (2000): Identifying fixations and saccades in eye-tracking protocols.