CloudResearch is a technology company that optimizes many participant recruitment platforms for scientific research. Mechanical Turk (MTurk) is one platform that we work with. We also work with dozens of market research platforms (Prime Panels). Each platform has its own participant pool, referred to as an opt-in panel. Participants on these panels are profiled on hundreds of variables. Invitations are sent via email and dashboards to specific participants, based on their demographic profile. Depending on the study, we may use one or more platforms based on the study's needs. In cases where the target group is very hard to reach a study may be feasible only when combining the resources of multiple platforms.
This allows for more specific and representative samples, as well as samples that could not otherwise be attained using MTurk.