  Social media in scientific research offer a unique digital observatory of
human behaviours and hence great opportunities to conduct research at large
scale answering complex sociodemographic questions. We focus on the
identification and assessment of biases in social media administered surveys.
This study aims to shed light on population, self-selection and behavioural
biases, empirically comparing the consistency between self-reported information
collected traditionally versus social media administered questionnaires,
including demographic and psychometric attributes. We engaged a demographically
representative cohort of young adults in Italy (approximately 4,000
participants) in taking a traditionally administered online survey and then,
after one year, we invited them to use our ad hoc Facebook application (988
accepted) where they filled in part of the initial survey. We assess the
statistically significant differences indicating population, self-selection,
and behavioural biases due to the different context in which the questionnaire
is administered. Our findings suggest that surveys administered on Facebook do
not exhibit major biases with respect to traditionally administered surveys
neither in terms of demographics, nor personality traits. Loyalty, authority,
and social binding values were higher in the Facebook platform, probably due to
the platform's intrinsic social character. We conclude, that Facebook apps are
valid research tools for administering demographic and psychometric surveys
provided that the entailed biases are taken into consideration. We contribute
to the characterisation of Facebook apps as a valid scientific tool to
administer demographic and psychometric surveys, and to the assessment of
population, self-selection, and behavioural biases in the collected data.
