Suggested citation — Bai, H. (2018). Evidence that a large amount of low-quality responses on MTurk can be detected with repeated GPS coordinates. https://www.maxhuibai.com/blog/evidence-that-responses-from-repeating-gps-are-random
The predictive power of known variables does not hold up for repeaters as it does for non-repeaters — evidence that repeaters, whatever they are, are not giving meaningful responses.
Measures included a four-item racial-identification scale, a three-item symbolic-threat scale, a single-item political-ideology measure (1 = very liberal to 7 = very conservative), and a single-item party-identification measure (1 = strong Democrat to 7 = strong Republican). Hypotheses, analysis plan, and data sharing were pre-registered.
Discussion · preserved verbatim from the original site · spam removed
Young-Jae Cha8/9/2018 01:53:01 am
Dear Max,
I appreciate your thoughtful notice about the possibility of data contamination. In my recent dataset (01/08), I found a data with "xx.88639831xxx" (I erased real numbers by using x intentionally). In this case, "88639831" is in the middle of consecutive numbers. Do you see this is the sign of a response from the bot?
Max8/9/2018 06:54:03 am
I would concern about it. Do their responses tend to look random and give non sensible answers to open ended responses (e.g, "GOOD" "very nice!")? Also, if you find that established scales do not work well on them, I would worry
Max8/9/2018 11:01:28 am
I think that is a possibility, but in the current issue, it seems that data from repeating GPS usually are far more random than non-repeaters, so I think that is a concern. GPS itself, I think, is just an artifact that happened to be helpful to identify likely problem responses...
Sam8/9/2018 09:22:29 am
In some of the repeating coordinates I've found in my most recent dataset it seems like whoever has done this is also spoofing these coordinates. For example, I have 4 respondents whose coordinates all lead to the middle of the Cheney reservoir in Kansas. Others I've found lead to places in the middle of nowhere in Venezuela, old warehouses, and other places that seem unlikely (or entirely impossible) to have any computers at all, much less internet access.
Max8/9/2018 11:06:51 am
I agree! IP is not the most reliable way to easily identify them yet, although some people said that it can be done
Elizabeth8/10/2018 09:34:08 am
This was helpful. From the initial email, I began to check my data. Became suspicious when I saw ~10 respondents from the Cheney Reservoir noted above in each survey. However, the article John noted and lack of other suspicious patterns in the data cleared concerns.
Phelim (Prolific)8/9/2018 10:28:01 am
Just posting in case there are concerns about this being an issue beyond Mturk. We haven't seen any evidence of similar bot-like accounts on Prolific (I'm Prolific's CTO). We have several processes in place to prevent these types of accounts. Including but not limited to the following:
1) Every account needs a unique non-VOIP phone number to verify.
2) We restrict signups based on IP and ISP (e.g. we allow common residential ISPs but block low-trustworthy IP/ISPS)
3) We limit to the number of accounts that can use the same IP address and the machine to prevent duplicate accounts.
4) We limit the number of unique IPs per "HIT" (study).
5) PayPal and Circle accounts for getting paid must be unique to a participant account. This means that in order to have 2 participant accounts that get paid, you would also need to have 2 PayPal accounts. PayPal and Circle also have steps to prevent duplicate accounts.
6) We take any data-quality reports very seriously and whenever researchers have suspicions about accounts they can report the relevant participant IDs to us we investigate the individual accounts as well as any shared patterns between them.
7) We analyse our internal data to monitor for unusual usage patterns.
If any Prolific users have concerns about bots, data-quality, or any other questions feel free to get in touch. We take these issues very seriously and do everything we can to make sure any data collected on our platform is trustworthy and reliable.
Max8/9/2018 11:09:09 am
Hi Phelim, thank you very much for your message! It is really reassuring to know that Prolific is taking it very seriously. Do you happen to have any data that you have access to and see if there is any repeating GPS (not IP)?
Phelim (Prolific)8/10/2018 03:11:53 am
We don't record GPS data I'm afraid, although we'll look in to recording this and working with any researchers who record this using our participants.
J8/9/2018 03:28:51 pm
I'm curious whether the following questions below have been discussed:
For the studies being affected, what are the MTurk presets (e.g. location, previous hits, rejection rate, payment rate)?
Are people finding that Turkprime is not detecting duplicate IP addresses or confirming locations accurately?
T8/9/2018 05:57:24 pm
I'm also curious about the HIT presets. Without appropriate presets, low quality workers are to be expected.
Brad Turner8/10/2018 08:37:43 am
Yes, I'd appreciate clarity on qualifications used as well. Also, I have to assume the supposed bots or their operators can take unique completion codes generated at the end of the Qualtrics survey and paste them back into MTurk. Can you confirm?
Kristin Broussard8/10/2018 08:50:32 am
I checked one of my recent data sets that was collected through Turk Prime today and found a huge number of repeat GPS coordinates (including 44 with .88639831 that passed 3 attention checks in the survey).
Kristin8/15/2018 04:19:33 am
Hi Brad,
Yes, the data is bad. The GPS is just a marker that's useful for pulling cases with bad data. What seems to be the real giveaway are the responses to open-ended questions (e.g., nonsensical responses, "good," "very," "nice,").
Also, as Max suggested, the reliabilities seem to be lower for theses flagged potential fraudsters/bots (although not necessarily low in an absolute sense), and, as noted by Tim Ryan, there are a high number that input "30" as their age on a type-in question and most chose "male" for their gender.
I do want to also note that I collected data for 4 different projects on mTurk and TurkPrime this summer and only one data set seems to be highly affected, even after planned exclusions for failing attention checks, etc. One data set seems completely unaffected (after cleaning for attention checks) and one other only had about 30 suspicious cases that passed attention checks.
Cori Faklaris8/9/2018 06:04:14 pm
Saw your post on Twitter and it rang a bell for me. I have also seen duplicate IP addresses in Mturk data, plus they are all ridiculously specific in decimal place - but that might be an issue with how they are assigned or recorded. I decided to look at the pattern of the specific responses as you did - unlike in your case though, my open ended responses weren't suspiciously out of context and the Likert responses didn't deviate noticeably from the aggregate. So I don't think our cases are similar issues. I wonder if you were targeted by a script due to the subject matter?
ctr8/10/2018 10:00:12 am
I have some open ended qualitative questions requiring an answer. Although the 88639831 data looks like outright junk, possibly made by a bot or more likely a human with poor english skills and low attention, the other repeating GPS coordinates appear to be mostly good data.
Mark8/10/2018 11:12:21 am
Per this very excellent article from Yale Law, you should be using code generation to match data received to payment requests on MTurk.
https://library.law.yale.edu/news/administering-qualtrics-surveys-mechanical-turk
Delete any other responses, which are far more likely to be bots.
Once matched, every data point corresponds to a *specific* MTurk user ID. To set up an account to get that ID the user must provide SSN or other tax ID information to be uniquely identified.
While GPS or IP might be easy to spoof - tax ID info is not. That means data issues reduce from a bot providing many bogus responses to individual users not really trying. Those users *can* come in groups (e.g., a community of people from a large college population just trying to get some extra cash) that share IP or GPS identifiers.
When we've used MTurk presets of 95% approval, 500 or more HITs completed, and usually for language purposes US only geographic region, we've found such data problems to be less than 2%.
Reject those workers.
If bots, you will never hear from them again - it costs more in time to follow up with you than they'll earn from the survey. And you'll help tarnish their MTurk approval rate to filter them out of future studies.
If they are real people they will likely email you after rejection complaining about the negative effect on their account and lack of payment. You'll very quickly be able to tell that they are not bots.
David Rand8/10/2018 11:21:15 am
We have not experienced this problem. I believe it's because we begin our HITs by having the workers transcribe a paragraph of handwritten text (essentially, complete a captcha). This is a trivial approach to screen out bots. I recommend it!
T8/11/2018 04:39:52 am
TurkPrime just released a report on the issue, analyzing 100,000 MTurk studies.
"In the last 24 hours, we have worked to determine whether there is a growing problem of multiple submissions from the same geolocation. In reviewing over 100,000 studies that have been launched on TurkPrime, we see that the rate of submissions from duplicate geolocations typically bounced from less than 1% to 2.5% within a study."
Over 97% of all studies had 2.5% or fewer duplicates, and they acknowledge duplicates "could be explained by people submitting surveys from the same building, office, internet service provider, or even the same city"
http://blog.turkprime.com/2018/08/concerns-about-bots-on-mechanical-turk.html
billy8/21/2018 11:20:14 am
Typical knee jerk reaction. All they can do is block duplicate gps, this does nothing but exclude hundreds of legitimate participants for no reason other than wanting increased privacy.
Katherine H.8/11/2018 07:38:57 am
I looked through some data I collected in February-March and found a few repeating GPS coordinates from the Cheney reservoir in Kansas. From what I can tell, they have the same IP addresses and different MTurk IDs.
Side note: My university IRB asks that I check the box to anonymize data collected on MTurk -- when I remember to do this, it means I don't collect IP address or GPS, making it more difficult for researchers to use this method to detect bots.
Julien (Lucid)8/14/2018 03:34:54 pm
Thanks for posting. I work on human and bot fraud detection at Lucid, and may have some pointers to avoid this.
First, IP address is a rather poor bot detection mechanism. IP addresses are very simple to spoof, and you can always use a VPN to mask your true origin. Using it as your only deduplication mechanism is just playing whack-a-mole. For the record, MaxMind outputs the IP as the "middle of nowhere" in Kansas when the incoming IP is absent or unreadable, so you can assume those invalid. Second, open text input is easily scripted by bots, so it's usually an easy tell.
We do a couple things to address these problems: no duplicate IP address, cookie, or participant ID can enter a same survey twice. We consider this table stakes for online research, so we offer this free of charge. Additionally, to the issue at hand, we use tools to detect gibberish, ungrammatical inputs, or even duplicate answers between participants. While researchers tend to avoid open-ended questions, they have proven a very good fraud detection mechanism.
We're happy to advise further on best security practices in online research.
www.luc.id
John Burger8/18/2018 09:56:03 am
MaxMind also uses the middle of Kansas when all it can tell about the ISP is that it's in the US. This will happen increasingly often with GDPR and other privacy regulations.
Sean8/17/2018 02:53:22 pm
My co-authors and I have just posted the following working paper to SSRN that investigates the root cause of this issue. Importantly, we find no evidence of bots.
https://ssrn.com/abstract=3233954
Alex8/28/2018 06:57:33 am
Hello,
While this seems like a good method to track scammers, it severely disadvantages those who use MTurk from home with their partners. Based on this study, my partner and I have both received rejections from a requested who utilized this resource.
Sincerely,
Alex
Wade9/20/2018 02:16:06 pm
Please report these worker IDs to Amazon that the problem can be corrected.
I would suggest using a 99% approval rate of at least 5000 HITs if you want quality results.
unanimous7/23/2019 12:41:35 pm
You know what?, this study is ridiculous, because of this, many mturkers who are legit and taking time finishing the survey being punished. That example of the nazi crap is just an opinion. How can you justify something from the opinion? If the question is right or wrong answer then justify it using that method.
That question is just like believing trump or not and justifying your answer using that method because you don't believe or believe on Trump. that's ridiculous! That's why it is called OPINION!!!