Online testing is sure to play a large part in the future of Psychology. Using Mechanical Turk or other crowdsourcing sites for research, psychologists can quickly and easily gather data for any study where the responses can be provided online. One concern, however, is that online samples may be less motivated to pay attention to the tasks they are participating in. Not only is nobody watching how they do these online experiments, they whole experience is framed as a work-for-cash gig, so there is pressure to complete any activity as quickly and with as low effort as possible. To the extent that the online participants are satisficing or skimping on their attention, can we trust the data?
A newly submitted paper uses data from the Many Labs 3 project, which recruited over 3000 participants from both online and University campus samples, to test the idea that online samples are different from the traditional offline samples used by academic psychologists:
The findings strike a note of optimism, if you’re into online testing (perhaps less so if you use traditional university samples):
Mechanical Turk workers report paying more attention and exerting more effort than undergraduate students. Mechanical Turk workers were also more likely to pass an instructional manipulation check than undergraduate students. Based on these results, it appears that concerns over participant inattentiveness may be more applicable to samples recruited from traditional university participant pools than from Mechanical Turk
This fits with previous reports showing high consistency when classic effects are tested online, and with reports that satisficing may have been very high in offline samples, we just weren’t testing for it.
However, an issue I haven’t seen discussed is whether, because of the relatively small pool of participants taking experiments on MTurk, online participants have an opportunity to get familiar with typical instructional manipulation checks (AKA ‘catch questions’, which are designed to check if you are paying attention). If online participants adapt to our manipulation checks, then the very experiments which set out to test if they are paying more attention may not be reliable.
This paper provides a useful overview: Conducting perception research over the internet: a tutorial review