Frequently Asked Questions about the Mangold Vision Eye Tracking System
1. Is the Mangold Vision Eye Tracker suitable for studies with children?
Yes. Eye Tracking studies with Mangold Vision and children were done in the past and achieved good as well as significant results.
Some examples are: Bolden, D., Barmby, P., Raine, S., Gardner, M. (2015): „How young children view mathematical representations: a study using eye-tracking technology“, von Rader, N., Zukow-Goldring, P., Miller, S. (2013): „Dynamic synchronous gestures assist word learning in low functioning ASD Children“ und Elician Celine Wartman, Nancy Riccardi, Nancy Rader: „Gaze Patterns to a Speaker's Face in Typically Developing and ASD Children“. Downloads and links to these publications can be found at our website at https://www.mangold-international.com/en/about-us/references/publications.
2. Is the so called head motion range important for data accuracy?
This range, aka “head box” is no indicator for the accuracy of an Eye Tracking System. It only indicates the spatial area (width, height, depth) where the eye tracking camera can (still) capture the participant’s eyes. I.e. this range denotes the movement range, the participant is allowed to make during a test, without losing the gaze data of that person. The VT3 mini head box is really big (WxHxD): 31.5 x 22.5 x 35 cm (12.4 x 8.9 x 13.8 in). It is unlikely that a participants is moving out of that range during a test, unless she/he is very restless.
Thus, the myth of “The bigger the head box the better” is not entirely true, because precision of gaze data is much more influenced by some other factors:
All eye tracker calculate a mathematical model of the participant’s eyes during calibration. This model represents the position of the test person´s eyes in relation to the screen. All eye movements are subsequently mapped to points on the screen, based on this mathematical model. So, the less the test person is behaving differently during the test versus during the calibration procedure - the more accurate the calculated gaze points will be.
An important data accuracy factor is also the speed of image processing. Here, Mangold Vision is taking the lead. The Mangold Vision eye tracker has an integrated on-board computer where the image processing takes place (Instead of processing the images on the connected PC). With that high speed on-board processing, all the image data is processed immediately. In this way, head motions are compensated really fast and the recorded data has a reliable quality.
3. How does calibration work?
At the beginning of each test, a 5, 9 or 16 point calibration is done. Before the calibration happens, other stimuli (e.g. instructions or images) can be shown. In our experience, a 5 point calibration is sufficient, because other factors are decisive.
4. What’s the typical operating distance?
With the VT3 mini Eye Tracker, a distance between user and screen of 60 cm (24.6 in) is ideal, because the camera optics is optimized to this. Including the above mentioned head box, this results in a total range of 45 – 80 cm (17.7 – 31.4 in), which is a common and ideal computer working distance.
For large displays Mangold offers so called long distance eye tracker, which work on really large screens and in a distance of several meters (several 40 inches). They can be used e.g. for museums, supermarkets or shopping malls or multimedia installations.
5. Can it be used with people wearing glasses or lenses?
Glasses and contact lenses are not influencing the eye tracking test, as long as the light conditions do not produce reflections on those glasses which make the pupil invisible for the eye tracking camera. This can easily be handled by creating appropriate light conditions. Also glasses with very small frames may cover the pupil in certain head positions.
6. What happens if the participant looks away from the screen?
Blinking and looking away from the computer screen is unproblematic, because the gaze tracker re-tracks the eyes very fast, when the participant looks back on to the screen and her/his eyes re-appear in the tracker’s field of view.
7. On which computer systems can the Mangold Vision system be used?
Mangold Vision runs on almost any Windows PC, from Win 7 and higher and under Mac with „Parallels desktop“. You can even use your own computer or get a recommended system from Mangold.
8. How user-friendly is the Mangold Vision Eye Tracking system?
The VT3 mini Eye Tracker is small (size 25.4 x 2.6 x 3.2 cm), light-weight (0.21 kg) and protected with a robust aluminum housing. It is placed directly under the screen or at the laptop keyboard with our supplied stand, or mounted directly under the screen with the included magnetic strip. With only one USB cable it is plugged into the PC/laptop.
The entire calibration process and all data recording works automatically. The Mangold Vision recording system is designed to work as a one-push-button solution.
9. What has the highest impact on data quality and on expected results?
The design of your individual study is the most influential force! The question you should always ask yourself: “Can we answer the desired research questions with this study. And are the subjects appropriate for this kind of data collection?”
The second important factor is the test leader / moderator who should make the test person feel comfortable, so that she / he behaves “natural” and “concentrated”.
The remaining are technical framework conditions which have to be observed, so that the gaze tracking camera can track the eyes stable and the position of the test person does only vary little in relation to the calibration position.
10. Which kinds of stimuli can be presented during my eye tracking tests?
A multitude of different stimuli can be presented through Mangold Vision on the computer screen: Images, videos, EPrime tests, Superlab tests and all activities which can be done on the computer, like surfing the web, using a PC application (games, chats, forums, social media applications, collaborative working applications etc.).
12. Which kind of analysis offers the Mangold Vision Eye Tracking System?
The Mangold Vision Analyzer offers various methods of visualizing the recorded gaze data and turning them into statistical results. See more here
Additionally, socio-demographic data or data from on-screen questionnaires can be collected during the tests. This allows for easy data selection during analysis and replay (e.g. “Show the data of all female users at the age of… who said … about the stimulus …”).
13. Can the user’s behavior be recorded as well?
Yes. Mangold Vision can record the user’s behavior and speech through a connected web camera. This video is replayed in sync to each recorded stimulus during analysis. It allows to better understand a user’s gaze pattern, because it shows the user’s context and lets you hear the user’s spoken comments. Both add a high value to almost any observational study.
14. Is it possible to add EEG and other physiological data to studies done with Mangold Vision?
15. Is the Mangold Vision system portable?
Yes, sure. The VT3 mini Eye Tracker is easily portable (size: 25.4 x 2.6 x 3.2 cm), very robust because of its light-weight metal housing. Therefore, it is ideal to carry-on for field studies.