createHIT method

Future<CreateHITResponse> createHIT({
  1. required int assignmentDurationInSeconds,
  2. required String description,
  3. required int lifetimeInSeconds,
  4. required String reward,
  5. required String title,
  6. ReviewPolicy? assignmentReviewPolicy,
  7. int? autoApprovalDelayInSeconds,
  8. String? hITLayoutId,
  9. List<HITLayoutParameter>? hITLayoutParameters,
  10. ReviewPolicy? hITReviewPolicy,
  11. String? keywords,
  12. int? maxAssignments,
  13. List<QualificationRequirement>? qualificationRequirements,
  14. String? question,
  15. String? requesterAnnotation,
  16. String? uniqueRequestToken,
})

The CreateHIT operation creates a new Human Intelligence Task (HIT). The new HIT is made available for Workers to find and accept on the Amazon Mechanical Turk website.

This operation allows you to specify a new HIT by passing in values for the properties of the HIT, such as its title, reward amount and number of assignments. When you pass these values to CreateHIT, a new HIT is created for you, with a new HITTypeID. The HITTypeID can be used to create additional HITs in the future without needing to specify common parameters such as the title, description and reward amount each time.

An alternative way to create HITs is to first generate a HITTypeID using the CreateHITType operation and then call the CreateHITWithHITType operation. This is the recommended best practice for Requesters who are creating large numbers of HITs.

CreateHIT also supports several ways to provide question data: by providing a value for the Question parameter that fully specifies the contents of the HIT, or by providing a HitLayoutId and associated HitLayoutParameters.

May throw ServiceFault. May throw RequestError.

Parameter assignmentDurationInSeconds : The amount of time, in seconds, that a Worker has to complete the HIT after accepting it. If a Worker does not complete the assignment within the specified duration, the assignment is considered abandoned. If the HIT is still active (that is, its lifetime has not elapsed), the assignment becomes available for other users to find and accept.

Parameter description : A general description of the HIT. A description includes detailed information about the kind of task the HIT contains. On the Amazon Mechanical Turk web site, the HIT description appears in the expanded view of search results, and in the HIT and assignment screens. A good description gives the user enough information to evaluate the HIT before accepting it.

Parameter lifetimeInSeconds : An amount of time, in seconds, after which the HIT is no longer available for users to accept. After the lifetime of the HIT elapses, the HIT no longer appears in HIT searches, even if not all of the assignments for the HIT have been accepted.

Parameter reward : The amount of money the Requester will pay a Worker for successfully completing the HIT.

Parameter title : The title of the HIT. A title should be short and descriptive about the kind of task the HIT contains. On the Amazon Mechanical Turk web site, the HIT title appears in search results, and everywhere the HIT is mentioned.

Parameter assignmentReviewPolicy : The Assignment-level Review Policy applies to the assignments under the HIT. You can specify for Mechanical Turk to take various actions based on the policy.

Parameter autoApprovalDelayInSeconds : The number of seconds after an assignment for the HIT has been submitted, after which the assignment is considered Approved automatically unless the Requester explicitly rejects it.

Parameter hITLayoutId : The HITLayoutId allows you to use a pre-existing HIT design with placeholder values and create an additional HIT by providing those values as HITLayoutParameters.

Constraints: Either a Question parameter or a HITLayoutId parameter must be provided.

Parameter hITLayoutParameters : If the HITLayoutId is provided, any placeholder values must be filled in with values using the HITLayoutParameter structure. For more information, see HITLayout.

Parameter hITReviewPolicy : The HIT-level Review Policy applies to the HIT. You can specify for Mechanical Turk to take various actions based on the policy.

Parameter keywords : One or more words or phrases that describe the HIT, separated by commas. These words are used in searches to find HITs.

Parameter maxAssignments : The number of times the HIT can be accepted and completed before the HIT becomes unavailable.

Parameter qualificationRequirements : Conditions that a Worker's Qualifications must meet in order to accept the HIT. A HIT can have between zero and ten Qualification requirements. All requirements must be met in order for a Worker to accept the HIT. Additionally, other actions can be restricted using the ActionsGuarded field on each QualificationRequirement structure.

Parameter question : The data the person completing the HIT uses to produce the results.

Constraints: Must be a QuestionForm data structure, an ExternalQuestion data structure, or an HTMLQuestion data structure. The XML question data must not be larger than 64 kilobytes (65,535 bytes) in size, including whitespace.

Either a Question parameter or a HITLayoutId parameter must be provided.

Parameter requesterAnnotation : An arbitrary data field. The RequesterAnnotation parameter lets your application attach arbitrary data to the HIT for tracking purposes. For example, this parameter could be an identifier internal to the Requester's application that corresponds with the HIT.

The RequesterAnnotation parameter for a HIT is only visible to the Requester who created the HIT. It is not shown to the Worker, or any other Requester.

The RequesterAnnotation parameter may be different for each HIT you submit. It does not affect how your HITs are grouped.

Parameter uniqueRequestToken : A unique identifier for this request which allows you to retry the call on error without creating duplicate HITs. This is useful in cases such as network timeouts where it is unclear whether or not the call succeeded on the server. If the HIT already exists in the system from a previous call using the same UniqueRequestToken, subsequent calls will return a AWS.MechanicalTurk.HitAlreadyExists error with a message containing the HITId.

Implementation

Future<CreateHITResponse> createHIT({
  required int assignmentDurationInSeconds,
  required String description,
  required int lifetimeInSeconds,
  required String reward,
  required String title,
  ReviewPolicy? assignmentReviewPolicy,
  int? autoApprovalDelayInSeconds,
  String? hITLayoutId,
  List<HITLayoutParameter>? hITLayoutParameters,
  ReviewPolicy? hITReviewPolicy,
  String? keywords,
  int? maxAssignments,
  List<QualificationRequirement>? qualificationRequirements,
  String? question,
  String? requesterAnnotation,
  String? uniqueRequestToken,
}) async {
  ArgumentError.checkNotNull(
      assignmentDurationInSeconds, 'assignmentDurationInSeconds');
  ArgumentError.checkNotNull(description, 'description');
  ArgumentError.checkNotNull(lifetimeInSeconds, 'lifetimeInSeconds');
  ArgumentError.checkNotNull(reward, 'reward');
  ArgumentError.checkNotNull(title, 'title');
  _s.validateStringLength(
    'hITLayoutId',
    hITLayoutId,
    1,
    64,
  );
  _s.validateStringLength(
    'uniqueRequestToken',
    uniqueRequestToken,
    1,
    64,
  );
  final headers = <String, String>{
    'Content-Type': 'application/x-amz-json-1.1',
    'X-Amz-Target': 'MTurkRequesterServiceV20170117.CreateHIT'
  };
  final jsonResponse = await _protocol.send(
    method: 'POST',
    requestUri: '/',
    exceptionFnMap: _exceptionFns,
    // TODO queryParams
    headers: headers,
    payload: {
      'AssignmentDurationInSeconds': assignmentDurationInSeconds,
      'Description': description,
      'LifetimeInSeconds': lifetimeInSeconds,
      'Reward': reward,
      'Title': title,
      if (assignmentReviewPolicy != null)
        'AssignmentReviewPolicy': assignmentReviewPolicy,
      if (autoApprovalDelayInSeconds != null)
        'AutoApprovalDelayInSeconds': autoApprovalDelayInSeconds,
      if (hITLayoutId != null) 'HITLayoutId': hITLayoutId,
      if (hITLayoutParameters != null)
        'HITLayoutParameters': hITLayoutParameters,
      if (hITReviewPolicy != null) 'HITReviewPolicy': hITReviewPolicy,
      if (keywords != null) 'Keywords': keywords,
      if (maxAssignments != null) 'MaxAssignments': maxAssignments,
      if (qualificationRequirements != null)
        'QualificationRequirements': qualificationRequirements,
      if (question != null) 'Question': question,
      if (requesterAnnotation != null)
        'RequesterAnnotation': requesterAnnotation,
      if (uniqueRequestToken != null)
        'UniqueRequestToken': uniqueRequestToken,
    },
  );

  return CreateHITResponse.fromJson(jsonResponse.body);
}