***Apologies for cross-posting***

Dear colleagues,

We would like to invite you to submit papers to our session on P*assive Smartphone Data Collection and Additional Tasks in Mobile Web Surveys: Willingness, Non-participation, Consent, and Ethics* at the ESRA Conference (July 15-19, 2019 in Zagreb). You can submit your abstract using the conference website: https://www.europeansurveyresearch.org/conferences/register The closing date for the submission of abstracts is *November 18, 2018*.

Here is the abstract for our session:

*Passive Smartphone Data Collection and Additional Tasks in Mobile Web Surveys: Willingness, Non-participation, Consent, and Ethics*

Smartphones allow researchers to collect data through sensors such as GPS and accelerometers to study movement and passively collect data such as browsing history and app usage in addition to self-reports. Passive mobile data collection allows researchers to broaden the scope of the research questions that can be answered and can potentially decrease measurement errors and reduce respondent burden. However, there are issues of selectivity, representativeness, and ethics of collecting such data. Respondents have to be willing to provide access to sensor data or perform additional tasks such as downloading apps, taking pictures, and providing access to their smartphone's data. If respondents who are willing to engage in these tasks differ from nonwilling smartphone users, results based on passively collected data might be biased. Moreover, little to date is known about how to ask for informed consent in passive data collection studies. In this session, we aim to bring together empirical evidence on the state-of-the-art use of sensor measurement and other additional tasks on smartphones in combination with mobile web surveys. We welcome presentations of results from (large-scale) studies with diverse sensors and tasks from multiple countries and research settings. Possible topics can include:

- current practice in collecting passive / smartphone sensor data - implementation, wording, and placement of consent questions - willingness to allow smartphone sensor measurements - willingness to perform additional tasks using smartphones - nonparticipation bias in studies using smartphone sensor measurements - ethical issues and privacy concerns when collecting passive data

Looking forward to seeing you at the ESRA conference, Florian Keusch and Bella Struminskaya