FAQs

About Amazon Mechanical Turk

Payments & Fees

Design, Publish, and Manage HITs

About Amazon Mechanical Turk

What is Amazon Mechanical Turk?

In 1769, Hungarian nobleman Wolfgang von Kempelen astonished Europe by building a mechanical chess-playing automaton that defeated nearly every opponent it faced. A life-sized wooden mannequin, adorned with a fur-trimmed robe and a turban, Kempelen's “Turk” was seated behind a cabinet and toured Europe, confounding such brilliant challengers as Benjamin Franklin and Napoleon Bonaparte. To persuade skeptical audiences, Kempelen would slide open the cabinet's doors to reveal the intricate set of gears, cogs and springs that powered his invention. He convinced them that he had built a machine that made decisions using artificial intelligence. What they did not know was the secret behind the Mechanical Turk: a chess master cleverly concealed inside.

Today, we build complex software applications based on the things computers do well, such as storing and retrieving large amounts of information or rapidly performing calculations. However, humans still significantly outperform the most powerful computers at completing such simple tasks as identifying objects in photographs – something children can do even before they learn to speak.

When we think of interfaces between human beings and computers, we usually assume that the human being is the one requesting that a task be completed, and the computer is completing the task and providing the results. What if this process was reversed and a computer program could ask a human being to perform a task and return the results? What if it could coordinate many human beings to perform a task?

Amazon Mechanical Turk (MTurk) provides a service for service requesters (hereafter “Requesters”) to integrate Artificial Artificial Intelligence directly into their applications by making requests of humans. Requesters can use the MTurk web user interface or web services API to submit tasks to the MTurk web site, approve completed tasks, and incorporate the answers into their applications. When using the web services API, the transaction looks very much like any remote procedure call – the application sends the request, and the service returns the results. In reality, a network of human Workers (hereafter “Workers”) fuels this Artificial Artificial Intelligence by coming to the web site, searching for and completing tasks, and receiving reward for their work.

All Requesters need to do is write normal code. The pseudo code below illustrates how simple this can be.


  read(photo);
  photoContainsHuman = callMechanicalTurk(photo);

  if (photoContainsHuman == TRUE) {
      acceptPhoto();
  } else {
      rejectPhoto();
  }
						

What problem does Amazon Mechanical Turk solve?

  • For software developers, the Amazon Mechanical Turk (MTurk) web service solves the problem of building applications that until now have not worked well without human intelligence. Humans are much more effective at solving some types of problems, like finding specific objects in pictures, evaluating beauty, or translating text. The idea of the MTurk web service is to give developers a programmable interface to a network of humans to solve these kinds of problems and incorporate this human intelligence into their applications.
  • For businesses and entrepreneurs who want tasks completed, the MTurk service solves the problem of accessing a vast network of human intelligence with the efficiencies and cost-effectiveness of computers. Oftentimes people do not move forward with certain projects because the cost to establish a network of skilled Workers to do the work outweighs the value of completing it. By turning the fixed costs into variable costs that scale with their needs, the MTurk web service eliminates this barrier and allows projects to be completed that before were not economical.
  • For people who want to earn money in their spare time, the MTurk web site solves the problem of finding work you can do wherever and whenever you want using the skills you already possess.

How do Requesters ensure their tasks are completed in a high-quality manner?

Requesters have several options for ensuring their HITs (Human Intelligence Tasks) are completed in a high-quality manner.
  • Requesters have the opportunity to approve completed HITs before having to pay for them. There are many ways Requesters can approve HITs, ranging from auto-approving them sight unseen, to auto-approving them when they receive two answers to the same HIT that match, to manually approving some or all completed HITs.
  • Requesters can specify that people who work on their tasks must first complete a qualification test, thus giving Requesters the opportunity to vet the skill level of the people working on their HITs beforehand. Over time people who do work on the Amazon Mechanical Turk web site will have statistics associated with them based on how accurately they have completed other HITs. These statistics, such as the percentage of HITs they've submitted that have been approved, allow Requesters to specify further that only Workers with certain qualifications can work on their HITs.

Who completes the tasks on Amazon Mechanical Turk and how do they complete them?

  • Virtually anyone can complete tasks on the Amazon Mechanical Turk (MTurk) web site using the skills they already have and according to their own schedule. The only requirement to complete tasks and collect payment from Requesters is a computing device connected to the Internet and to be at least 18-years-old.
  • Earning money through the MTurk web site is as easy as searching for HITs on the site, accepting those HITs, completing them, and collecting the reward once the HIT is approved by the Requester.
  • To make money by completing tasks using the MTurk web site, visit worker.mturk.com.

What kind of work can be done using Amazon Mechanical Turk?

  • Anyone can submit virtually any task that can be completed using a computing device connected to the Internet.
  • Amazon came up with the idea for Amazon Mechanical Turk to help solve specific internal data processing problems that required human judgment and intelligence. We quickly realized that we had invented something unique and incredibly useful, and decided to expose it as an external web service so that Requesters can create their own innovative applications that use human intelligence as a core component.

How do Workers collect money for the tasks they complete?

When a Requester approves a task, Amazon Mechanical Turk (MTurk) transfers Requester funds to the MTurk account of the Worker who completed the task. Workers in the United States can transfer earnings to their Amazon Payments account or to their Amazon.com gift card balance. Workers outside of the United States can transfer earnings to their Amazon.com gift card balance, and some Workers may be eligible to transfer earnings to their bank accounts.

Can any business use Amazon Mechanical Turk or do they need to understand how to use web services and APIs?

Businesses can create and publish HITs on Amazon Mechanical Turk using the Requester web user interface (UI), the API, or the command line interface (CLI). Visit the Requester User Interface Guide to learn more about the UI or the developer getting started guide to learn about the API or CLI.

Can Requesters outside of the US use Amazon Mechanical Turk to get tasks completed?

We currently accept registrations from the following countries:

Americas

Barbados, Chile, Canada, French Guiana, Guadeloupe, Martinique, Puerto Rico, United States, US Minor Islands, US Virgin Islands

Africa

Botswana, Mayotte, Réunion, South Africa

Asia and Pacific

Australia, French Polynesia, French Southern Territories, Hong Kong, Israel, Japan, New Caledonia, New Zealand, Qatar, Singapore, South Korea, Taiwan

Europe

Austria, Belgium, Denmark, Estonia, Finland, France, Germany, Iceland, Ireland, Italy, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovenia, Spain, Sweden, Switzerland, United Kingdom

We're working hard to make Amazon Mechanical Turk (MTurk) available for more Requesters. Want to suggest a country? Let us know.

Where can I view and edit my name, email address, password, and payment methods

You can view and edit your account information by accessing your My Account page. Please note that your MTurk Requester account is associated with your Amazon.com account so when you edit your personal settings, they will be changed on the corresponding Amazon.com account.

Where can I view and edit my contact address information?

You can view and edit your contact address on Amazon.com.

Payments & Fees

How do I purchase prepaid HITs on Amazon Mechanical Turk?

Follow these steps to purchase prepaid HITs:
  1. From your Amazon Mechanical Turk account, go to My Account -> Purchase Prepaid HITs.
  2. Enter in the amount you would like to purchase.
  3. Select the credit or debit card on file or enter in new credit or debit card information.
  4. Confirm your purchase.

Note: As a US Requester, you may be prompted to establish a verified Amazon Payments account if you plan to make a purchase above certain amounts. You can create a verified Amazon Payments account at any time here.

How are the fees calculated?

You can review Amazon Mechanical Turk pricing here.

What rounding rules are applied when calculating fees?

After the fee is calculated, we round half up amounts greater than $0.01 – we round down if the fractional amount is less than half a penny, and round up otherwise. For example, $0.104 is rounded to $0.10, $0.105 is rounded to $0.11, and $0.108 is rounded to $0.11.

How are Workers paid?

Workers will be paid and Amazon Mechanical Turk (MTurk) fees will be charged when you approve submitted work. If you reject the work, the Worker is not paid and you are not charged the MTurk fees. MTurk Prepaid HITs are subject to Participation Agreement. You can review MTurk pricing here.

Can I use any Amazon Payments account to purchase prepaid HITs?

No. You can purchase prepaid HITs using your credit or debit card on the Purchase Prepaid HITs page.

How do I receive a refund for prepaid HITs?

If you would like a refund of your prepaid HIT purchase, please contact customer support.

Can I purchase prepaid HITs through my AWS account?

We don't support purchases of prepaid HITs through your AWS billing account. You can purchase prepaid HITs within Amazon Mechanical Turk at the My Account page.

Who are Amazon Mechanical Turk Masters?

Amazon Mechanical Turk (MTurk) has built technology which analyzes Worker performance, identifies high performing Workers, and monitors their performance over time. Workers who have demonstrated excellence across a wide range of HITs are awarded the Masters Qualification. Masters must continue to pass our statistical monitoring to maintain the MTurk Masters Qualification.

Do you collect tax reporting information from non-US based Workers?

Yes, all non-U.S. based Workers are required to provide their tax information through a tax information interview before doing any work on Mechanical Turk just as U.S. Workers are required to do. The tax information interview collects the U.S. tax status (for U.S. person or non-U.S. person), the name, and the permanent residence address of the individual that will report the income on an income tax return.

What are funds held for liability?

Funds held for liability is the sum of your assignment liability and fee liability.

Funds held for assignment liability is an estimated amount representing how much you would have to pay Workers if Workers submitted results for every assignment you are requesting, and you approved all of the results. We hold these funds because we need to ensure that Workers are paid promptly for their work on Amazon Mechanical Turk (MTurk). Your assignment liability will increase as you create new HITs and will decrease as you approve or reject assignments. If you have no outstanding assignments, you will have zero assignment liability.

Funds held for fee liability is an estimated amount representing how much you would have to pay MTurk if Workers submitted results for every assignment you are requesting, and you approved all of the results. Your fee liability will increase as you create new HITs and will decrease as you approve or reject assignments. If you have no outstanding assignments, you will have zero fee liability.

Design, Publish, and Manage HITs

How do I create a HIT?

The help center contains helpful guides, videos, webinars, case studies and other tools to help you get started and manage your HITs. The Amazon Mechanical Turk (MTurk) Requester website is ideal for business professionals who want access to the MTurk Worker community. The Requester UI Guide will explain how to design, publish, and manage your HITs on the Requester website.

What happens when I reject work?

When you reject an assignment, the Worker who performed the assignment does not get paid, and you are not charged the standard Amazon Mechanical Turk fee for the HIT. The rejection may affect your reputation as a Requester and the approval rate of the Worker who submitted the results. Please note that you may not reject an assignment without good cause.

How long does Amazon Mechanical Turk keep my HITs?

MTurk will remove HITs and corresponding Assignment data from your account after 120 days. If you require access to HIT and Assignment data for longer than 120 days, we recommend you download the HIT results and store them locally.

Are there restrictions or prohibited uses of Amazon Mechanical Turk?

You may not use Amazon Mechanical Turk for illegal or objectionable activities. Please refer to the policy page for examples. For example, Requesters are not allowed to collect personally identifiable information from Workers.

How do I prevent Workers who have worked on my HIT (e.g. Surveys) once from taking part in subsequent HITs?

This can be achieved by using qualifications. Requesters can create a Qualification Type or use an existing Qualification Type to assign it to the Workers who have completed the HIT (e.g. survey) once. When creating the next HIT, Requesters can specify that only Workers who have not been granted the Qualification Type can work on the HIT. This can be done through the UI and the API.

How do I use Premium Qualifications?

Requesters can specify criteria at the time of creating the project. The available attributes can be specified in the “Worker Requirements” section of the Requester Website. To suggest a new Premium Qualification for consideration, or to share feedback about this feature, please complete this two question survey.

Can I use Premium Qualifications for any kind of HIT?

Yes, using the Create Project feature on the Requester Website, Requester customers can use Premium Qualifications for any kind of HIT that has 10 or more Assignments, including Surveys. The Sentiment and Categorization Project types do not support Qualifications, nor does the Create HITs Individually feature.

What is the cost of using Premium Qualifications?

The use of each of the Premium Qualifications incurs an additional fee per approved assignment based on the specific Premium Qualification chosen. For more detail, see our Pricing page.

How do I retry publishing a Batch with a failed payment?

You can retry publishing by following these three steps:
  1. If your batch had an input data file, download the input data file on the failed Batch Details page. You will need this file for Step 3.
  2. Go to: Create -> New Batch with an Existing Project, and click Publish Batch on the same Project you previously used.
  3. If your batch had an input data file, upload the input file from Step 1.
  4. Go through the remaining steps of publishing a batch.

If you continue to experience issues, please review your recent purchases on the My Account page.

What is the maximum number of HITs in a batch?

The maximum number of HITs in a batch is 250,000 (or 5,000 in our Sandbox environment).

In order to publish more than the maximum number of HITs at a time, you may break your input file into multiple smaller files containing less than or equal to the maximum number of HITs. If your use case requires you to publish more than the maximum number of HITs in a single batch, please contact us.

Can I create and manage HITs programmatically?

Amazon Mechanical Turk (MTurk) provides Requester facing APIs as well as developer tool kits (SDKs). To get started, visit our developer Getting Started Guide.

Why do I need to have an AWS account to use MTurk APIs?

In order to call the MTurk APIs, Requesters must have registered for AWS accounts and retrieved their IAM credentials. This is because MTurk uses the AWS account to identify and allow access for developers using the MTurk APIs. We’re not using AWS to track MTurk API usage thus MTurk will not appear in AWS bills for Requesters.

Can I use MTurk to publish tasks containing personal or sensitive data?

No. As a public crowd marketplace, MTurk is not designed for sharing or publishing HITs containing personal or sensitive data. It is your responsibility as a Requester to determine whether your HIT content contains any personal or sensitive data.

Can I post a survey on MTurk that asks Workers for basic demographic information?

Yes, so long as your survey does not derive any personally identifiable information from Workers. For example, you may ask Workers for their occupation, relationship status, etc., but you may not ask Workers for personally identifiable information, such as their full name, email address, phone number, or equivalent in any HIT including survey HITs. Surveys should only be posted for legitimate academic or market research purposes.

Are there restrictions on what I can use Worker IDs for?

Unique Worker IDs are made available by MTurk to facilitate your use of the MTurk service only and for no other purpose. For example, you may use Worker IDs to distinguish between Workers who complete your HITs, and manage Workers such as tracking how many HITs a particular Worker has completed. You may not use Worker IDs to try to derive the real identity of any Worker, or otherwise publicly post or share them.