Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

Martin Voracek,Elena Moltchanova,Christoph Bartneck,Andreas Duenser,Karolina Zawieska

doi:10.1371/journal.pone.0121595

Abstract

Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon’s Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

Highlights

When conducting an experimental study, the way of recruiting participants for the study may already introduce a certain bias and great care must be taken in this process
This study compares whether participants recruited through Amazon’s Mechanical Turk (AMT) give different responses than participants recruited through an online forum or recruited directly on a university campus
The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums

Summary

Introduction

When conducting an experimental study, the way of recruiting participants for the study may already introduce a certain bias and great care must be taken in this process. Recruiting students for studies is very common in many disciplines Mechanical Turk vs Traditional Methods psychology students for psychology experiments; recruiting computer science students for Human Computer Interaction (HCI) research) and potential bias due to this practice has been documented [1, 2]. Even when the scope of the recruitment is broadened to include participants from the entire campus, it cannot be assumed that results from such a study can be generalized to the general public [1, 3]. Recruiting participants online has become a viable alternative to recruiting participants directly. Invitations to participate in E-mail and Web-based surveys can reach a large number of participants and considerably reduce recruitment costs and time [4, 5]

Methods

Discussion

Conclusion