On average, around 40% of our respondents start their surveys on a mobile phone. This can be higher for millennials and in certain markets.
However, most surveys are still devised on larger laptop or desktop screens so it is important to understand how the questions appear on a mobile device. The software can automatically re-format questions to different orientations for a mobile ‘portrait’ screen (e.g. a horizontal scale on a laptop can become a vertical scale on a phone) so it is important to check and, if necessary, reformat to ensure consistency.
The only way to be sure is to test the survey on different devices and even then we will always check the soft launch data for unexpected differences between devices.