The NIH Toolbox app has been designed and extensively tested on iPad devices with screen sizes of 9.7 through 11 inches. When you use these devices, scores you obtain from participants will be consistent and can be confidently interpreted (reliable and valid, technically speaking). Extensive testing on other iPad screen sizes has not yet been completed, and thus it cannot be confirmed that the obtained scores can be interpreted with the same level of confidence.
For best results, please use iPad models that are 2016-to date with 9.7-11-inch screens. Please see this article for the list of supported devices.
Article is closed for comments.