Relevance & Research Question: Most survey questions are closed questions, where respondents have to select an answer from a proposed set of alternatives. However, a lot of surveys also include, at least occasionally, some open questions. Open questions that call for elaborated and developed answers, called “open narrative questions”, are used when the researchers want to go deeper into what the respondents think.

Methods & Data: This presentation compares the answers to open narrative questions when the respondent is participating in a PC survey, in a smartphone-not-optimised survey or in a smartphone-optimised survey. The experiment was carried out in Spain using data collected by the Netquest online access panel. Respondents were assigned randomly to each type of device and survey format, in two successive waves. Because respondents have to type in their answer, we expect differences between devices, linked with the size and the kind of keyboards (i.e. physical versus digital, touch-screen or not).

Results: The speed of answers is longer in smartphones, in particular in the non-optimized version. There is no difference in item non-response, in the proportions of "don't know" and the one of non-sense. However, the precision of answers is lower in both smartphones groups. The use of abbreviations is higher in smartphones (both groups) but overall quite low, so it cannot explain the differences in precision.

Added Value: Previous research was mainly based on one-wave survey, and/or small/specific samples, and non-sensitive questions. On the contrary, this study uses a full cross over design, with 3 control groups and 6 treatments groups. This allows to compare the answers both across but also within subject, to get more precise conclusions. In total 1,608 respondents of a large opt-in panel in Spain answered both waves. Also, sensitive topics are studied (e.g. about euthanasia or immigrants), for which we can expect more differences across devices, due to the portability of the smartphones (higher probability to have people around).