This article applies to:
When running E-Prime experiments, it is important to run on configurations where the aspect ratio of the monitor matches the resolution of the experiment or unexpected results can occur. For example, the ideal scenario for running an experiment with a resolution of 1024x768 is to use a monitor with a 4:3 aspect ratio.
Failure to use a proper monitor results in the edges of the display being stretched. For studies that are using E-Prime eye tracking extensions (Tobii Pro, EyeLink, Smart Eye, etc.), the stretching can be particularly problematic. Participant eye tracking data may be inaccurate at the edges of the monitor because the resolution must be stretched to fit another aspect ratio.
Please refer to the following article on Wikipedia for a listing of display resolutions and aspect ratios: https://en.wikipedia.org/wiki/List_of_common_resolutions. Ensuring that the display setup is correct should alleviate concerns with inaccurate display data.
Some video drivers do not permit stretching. With those configurations, black bars may be seen on the sides of the display as is the case with the image below (Surface Pro 3, recommended resolution = 2160x1440, actual resolution display = 1024x768).
Although these black bars may not be what a researcher wants to see, the presence of them is beneficial because they help to maintain the display's aspect ratio.