What is mTurk?

        mTurk, which stands for Mechanical Turk, is a service platform provided by Amazon which allows requesters to post various tasks or HITs for workers to do on their computer.

       The Turk, also known as the Mechanical Turk or Automaton Chess Player (German: Schachtürke, "chess Turk"' Hungarian: A Török), was a fake chess-playing machine constructed in the late 18th century. From 1770 until its destruction by fire in 1854, it was exhibited by various owners as an automaton, though it was exposed in the early 1820s as an elaborate hoax. Constructed and unveiled in 1770 by Wolfgang von Kempelen (1734–1804) to impress the Empress Maria Theresa of Austria, the mechanism appeared to be able to play a strong game of chess against a human opponent, as well as perform the knight's tour, a puzzle that requires the player to move a knight to occupy every square of a chessboard exactly once.

         Through mTurk, Amazon facilitates work between requesters and workers.

Requesters, which range from Universities to various companies, post work on mTurk in the form of human intelligence tasks (HITs). These HITs include surveys, SEO work, data mining, and other various tasks. Once completed by the worker, the requester will then approve or reject the work based on the workers performance. If approved, payment is made into the workers Amazon Payments account. 

How to work in Mturk.com

HOW TO WORK? simple video showing to submit a HIT

Batches

A batch HIT is a task that you can preform over and over again. These are good when you are trying to get your numbers up. Batches are usually HITs than can be done within a minute or two. Some can even be completed in under 10 seconds. Their pay is usually not the best, but they will increase your approval percentage incase of a rejection.

An easy way to search for large batch HITs is to sort your search results with the "HITs Available (most first)" option. This is located on the left side of the screen above all of the HITs that are available to do.

Surveys

A survey is a HIT that you can (usually) only preform once. They can be political, involve completing different tasks, games, and many other things. These are normally worth more per HIT than a batch HIT.

A good way to sort your batches is by selecting the option "HIT Creation Date (newest first)". This option can be found on the left side of the screen above the HITs from your search result. This will ensure that you are able to grab new HITs as soon as they are posted.

Qualifications

Many different HITs will require you to have specific qualifications. Examples of these qualifications are listed below.

• HIT approval is greater than 98%
• Total HITs approved is over 1000
• Location is US
• CastingWords PPT is not less than 80

Some of these are unchangeable (such as your location), while others you have to work in order to achieve (approval percentage and HITs approved). Other qualifications are ones that you have to obtain yourself. Many requestors will have a qualification you can request specfically for their HITs, and their HITs will be available only to those turkers that possess it.

Qualifications can be found under the Qualifications tab located at the top of the page.

Here you can find the tabs for qualifications you don't have yet, the ones you do have, and the ones that are currently pending.

Some qualifications will require you to take a short test in order to request them:

While others simply require you to click the request qualification button:

CAPTCHAS

There may be a time that you are in the middle of a batch and all of a sudden it wants you to enter in a short string of letters and numbers. This is called a captcha and is put in place to make sure that you are not a bot. You have 3 chances to enter the captcha in correctly or else your account will be halted for FIVE MINUTES.

However, even if a captcha is entered correctly, if someone else has already accepted that HIT... it will take it as incorrectly entered and count towards one of your three chances. In order to be able to quickly and correctly fill in a captcha and be able to get back to your batch, search for a requestor that is common and has many HITs put up. Fill in the captcha, accept the HIT, return it, and then proceed back to your batch.

10 Day Limitation

While you are on your first ten days as an approved Mturk worker, you are limited to 100 ACCEPTED HITs per day. This means that if you accept a HIT, and then return it, it still counts as one of your 100 daily allowed HITs.

Each day starts over at 12am PST (3am EST). This 10 day probation will only last 10 days as long as you complete at least 1 HIT for each of those days.

It is wise to take advantage and do the full 100 HITs daily in order to build up your numbers. At 12am PST on your 11th day, your HIT limit will increase to 3700-3800 submitted HITs; this number does not include HITs that have been returned.

PREVENT REJECTION

Why did I get rejected?

There could be many different reasons.

1. You did a HIT from a requester with a shady TO.
2. You completed the HIT too quickly when the requester said not to.
3. You failed an attention check.
4. You entered a wrong completion code, or forgot to enter a completion code.
5. You had already completed the same HIT for that specific requester already.

Is there anything Amazon can do about it?

To put it simply: No.

It is up the the requester's discretion as to whether or not reject you. Unless there is a case of a large mass rejection, Amazon does not get involved.

Is there anything I can do about it?

Possibly.

You can always try to politely contact the requester. Explain to them that getting a rejection hurts you as a worker on Mturk. Ask them to review your work, and provide them with a link on How to Reverse a Rejection.

What can I do in the future to prevent this?

A couple of things...

1. Download TurkOpticon and check out each requesters TO before considering accepting their HIT.

2. Check to see if you have done the HIT from that requester before.

3. If it looks familier, and the HIT says to not repeat it... RETURN IT.

4. Email the requester if you have any concerns about whether or not you have done that HIT before.

5. Always be careful, take your time, and try not to miss any attention checks within the HIT.

How To Reverse a Reject or demand Reverse Reject

 How To Reverse a Reject

Requester Reject Reversal Procedures

copy right,  visit the official Mechanical Turk blog.

In this article I will endeavor to explain how you, as a requester, can reverse rejected HITs for work performed on Amazon Mechanical Turk.

Why this is a good thing for both you and for the community is beyond the scope of this article but it bears mentioning here that it is. It is also worth mentioning that you need the funds available to pay for the HIT in order to reverse it - exactly like you would an approval, since a reversed reject is an approval.

Reject reversal is unfortunately not supported in the interface that Amazon makes available to requesters but that does not mean that it cannot be done (as even some AMT support personnel have been known to claim). It simply cannot be done through the default graphical interface that Amazon makes available.

Below I outline four different basic methods for reversing rejections in ascending order of technical difficulty. All of these make use of the AMT API, full documentation for which can be found at:http://docs.amazonwebservices.com/AW...e/Welcome.html

I
Contacting Amazon directly is, by far, the least technical method. Send a message to AMT support containing the AssignmentId of the rejected HIT and the WorkerIDs, if reversing for specific workers, you wish to approve and they will do the rest. I should point out here that I do not have any direct experience either using this method or having it used on my behalf. Amazon employees on Amazon forums have recommended this method for requesters who do not have the ability to make the API calls themselves. However, if you have a large number of HITs you want to un-reject they may very well tell you to follow one of the options below. The above method should work for a small number of rejections you would like to reverse. I would welcome feedback from anyone who has had experience with this method on either side, so I can fill out this section with a little more detail.

II
The second easiest and possibly least secure method to use is the published form at http://techlist.com/mturk/unReject.php to perform the reversal; just plug in the relevant data and you are done. Quick and easy, right?

Why this is potentially a bad idea:
The site where this interface is hosted is that of a third party, and is known to be at least somewhat unreliable in terms of availability.

The site where this interface is hosted does not support SSL (HTTPS) connections and this is a known fact. This means that there is nothing stopping any third party so inclined from extracting both your Access Key ID and your Secret Access Key from your request. Here is Amazon's cautionary statement regarding your secret access key:

The site where this interface is hosted does not support SSL (HTTPS) connections. If you are a member of an organization that is beholden to any of the many data privacy and/or data security standards (PCI/CISP, SOX, GLBA, HIPAA, anything in the ISO 27000 series, you get the idea) you could be very well risking your organization's certification and possibly even breaking the law.

The site where this interface is hosted is that of a third party and there is ultimately nothing stopping that third party (or another malicious third party who manages to gain access to their server) from logging the information you submit. In fact you can be relatively assured that this information will be logged.

III
The next on the chain of difficulty is to host the above form yourself. This makes the assumption that you have a web server available that you are capable of installing things on, but that you are not technically apt enough to address the AMT APIs directly. I include it here for completeness' sake as much as anything else. The page code can be acquired athttp://pastebin.com/raw.php?i=M909EsEj

IV
The final and most technically challenging, but also most flexible and ultimately - in my opinion - the best method is to write your own code to call the API using one of the SDKs that are available. There are open and up to date SDKs for:

C#, .NET
http://aws.amazon.com/code/Amazon-Mechanical-Turk/923

Java
http://aws.amazon.com/code/Amazon-Mechanical-Turk/695

Rubyhttp://aws.amazon.com/code/Amazon-Mechanical-Turk/793

Perlhttp://aws.amazon.com/code/Amazon-Mechanical-Turk/922 

If it were me doing it and there were no technological constraints, I would recommend the .NET API and using Powershell to write your automation. That combination has yielded the best results for me personally - but I will freely admit to being a little bit prejudiced. There is even a little tutorial on Amazon's site at:http://aws.amazon.com/articles/3801