Relevance & Research Question:
Most often, psychological studies participants are recruited with help of some selected organisations (universities, hospitals etc.). Usually they are invited to the study in direct face to face contact. Online research and recruitment are rare, partly due to the questioned validity caused be perceived too big anonymity.
Direct personal recruitment enables easy verification of participants identity and tend to better engage them. Yet, due to time and money limitations, it is often restricted only to few sources of participants that lead to too high level of sample homogeneity. Moreover, the results may be affected by perceived researcher's expectations and/or social desirability effects.
For my doctoral study I decided on wider range of recruitment methods. The important questions to be addressed for the use of this and future studies were about the usefulness and validity of this approach, i.e.: (1) effectiveness in terms of gathering possibly numerous and diversified sample, (2) reliability and similarity of results for various sub-samples.
Methods & Data: The respondents were couples expecting their first babies. They were filling in a profiling survey and psychological questionnaires (concerning their personal and relationship traits) online. They were recruited directly offline (at courses for pregnant couples and at trade fair with articles for babies) and indirectly online (mainly with the use of Market Research Access Panels, announcements on online forums and by on-site pop-up invitations). All together a few thousand people became invited.
Results: (1) Direct personal invitations were more effective in terms that they let more precisely reach the target group and they resulted in lower drop-out. However, due to the easily achieved scale effect, still indirect online recruitment provided the majority of the final sample. It also very much helped to obtain its higher diversity. (2) The data collected thanks to direct vs intermediated invitations did not differ significantly neither in terms of reliability nor in terms of average levels of the variables measured.
Added Value: Conclusions from the analysis may help to resolve the mistrust toward Internet research and encourage to use wider range of contact channels with participants in psychological studies.