Setting up quality control
Quality control lets you get more accurate responses and restrict access to tasks for cheating Tolokers. Quality control consists of rules. All rules work independently.
- Go to the pool editing page
- If you already have a pool with the appropriate quality control settings, you can copy it along with the audience settings. To do this, go to Tolokers filter and click Copy settings from... and then Add Quality Control Rule.
Under Quality Control, choose the rules you want to use.If you aren't sure what quality control rules you need, select a quality control preset with default settings.
- Make settings for the rules you added. Below is a list of rules with links to detailed information about the rule settings.
- Save the pool.
List of rules
- To keep track of how often Tolokers make mistakes:
- To protect your project from robots and cheaters:
- Captcha: Show a captcha from time to time to make sure tasks aren't completed by robots.
Always use one or more ways to control quality of answers.
Counting fast responses makes sense for most tasks.
If the Toloker has to provide a response as a text or link or upload a photo, the best way to control quality is by reviewing assignments. You can outsource task acceptance to Tolokers. Create a task with a question (for example, “Is this phrase translated correctly?”) and possible responses (for example, “yes”/“no”). Set up overlap and majority vote check.
Calculate the skill for each pool separately. The current skill value is the value of the skill in the pool the Toloker completed last. This option is convenient if:
The pools are intended for different groups of Tolokers (for example, there are filters by city or country).
Pools are started one by one and you don't want to take into account the responses in the previous pools to calculate the skill in the current pool.
This calculation method is used by default when adding a quality control rule to a pool. For the control tasks block, leave the Recent control task responses to use field empty.
Calculate skill based on all tasks in a project This option is good if the pools are small and you don't need to have skill calculated for each pool.
This option is available only for skills on control tasks. To use it, fill in the Recent control task responses to use field in pool quality control rules.
- You won't be able to correctly evaluate the quality of the Toloker's responses.
- The Toloker won't be interested in completing such tasks because they'll spend a lot of time studying instructions but won't earn much.
- A large pool with 1% of control tasks (good)
There are 10,000 tasks in the pool, and 100 of them are control tasks (1%). Each suite contains 10 tasks, and 1 of them is a control task. Hence, a user can complete up to 100 suites.
- A small pool with 1% control tasks (bad)
There are 100 tasks in the pool, and 1 of them is a control task (1%). Each suite contains 10 tasks, and 1 of them is a control task. Hence, each user can only complete 1 suite.
- A small pool with 10% control tasks (good)
There are 100 tasks in the pool, and 10 of them are control tasks (10%). Each suite contains 10 tasks, and 1 of them is a control task. Hence, each user can complete up to 100 suites
The settings for quality control rules depend on the type of tasks. General recommendations:
It is better to use one skill in a project. You can choose the way to calculate the skill:
Yes, of course — you can use the same skill for different projects. But most often, a skill is intended for a specific project. If the Toloker completes a certain task well, this doesn't mean that they will complete other ones successfully. Another disadvantage is that if you filter by skills that were set long ago, you will artificially limit the number of available Tolokers.
Yes. When you copy the filter and quality control settings, the settings you previously added manually are overwritten. You should see a warning about this in the copy settings window.
Yes, if they can access both pools, they can do both of them. To restrict access to subsequent tasks for a Toloker, use the Completed tasks rule and select a ban at the project level.
No, this is incorrect. With these settings, each time a rule condition is met, the Toloker gets
skill = 1. To change the skill value in the process of task review, you need a “multi-step” rule, which has multiple identical rules with different values of Total reviewed responses.
Yes, the fast response settings specify the time per task suite.
Another option for selecting Tolokers for a project of this type is assignment review (non-automatic acceptance).
The Recent control task responses to use field is for the number of recent responses from the Toloker. If you use non-automatic acceptance for your task, then to set up your intended rule you need to specify
3 in Total reviewed responses.
If you pass texts to the input data, you can load 2 different tasks in the pool. In one task, pass Text 1 in the
INPUT: <input field name> field, and in the other task, use this field to pass Text 2. But if the text is in the HTML block of the task template, you need to clone the project. To let a Toloker do only one task in your project, use the Submitted responses rule. You can assign a skill or ban the Toloker after they submit one response.
We recommend adding at least 1% of control tasks in the pool. And for small pools — 5-10%.
Each control task is shown to the Toloker only once. If you use smart mixing, you determine how many control tasks should be in a suite. If each suite contains one control task, then the maximum number of suites the Toloker can complete is equal to the number of control tasks in the pool. If you increase the number of control tasks in a suite, the number of suites available to the Toloker decreases by the same number.
There shouldn't be too few pages available. Otherwise:
If there are few control tasks in the open pool, add new control tasks.
In a large pool with few control tasks, a situation might occur when users who have completed a lot of tasks in the project stop getting new task suites. This happens when the Toloker completes all control tasks in the pool.
The Control tasks rule starts working after the Toloker completes the number of control tasks you specified. If your pool contains both training and control tasks, you can take into account the responses in both of them (the Number of responses parameter) or only in control tasks (the Number of control responses parameter).
As soon as the needed number of responses is collected, Toloka calculates the percentage of correct and incorrect responses and performs an action (assigns a skill, or blocks the Toloker in the pool or in the project). Then this percentage is updated as the tasks are completed by the Toloker. The number of the Toloker's recent responses that's used in the calculation is set in the Recent control task responses to use field. If you leave it empty, all the responses from the Toloker in the pool are counted.
Your training and control tasks have the same project specification. However, you can create a separate project with the tasks and assign a skill based on user responses. Then you can admit Tolokers to the main project based on their skill.
An exam pool contains only control tasks. It's usually small and used for checking how well users learned to do your tasks after they read the instructions and completed the training. Unlike your main pool, you already know the correct responses for every task in this pool. You can set the price to zero.
Based on the results of responses to control tasks, you can assign a skill to the Tolokers and then specify it in the main pool as a filter. For example,
MySkill = 80 or = Is missing. You don't have to create an exam. For simple tasks, the training pool provides enough practice, but many requesters also use exams.
When you load tasks, use smart mixing. In this case, you'll have infinite overlap in your exam.
However, this poses the risk that you might spend a lot of money on the exam. You might want to open this pool only when the main pool opens, and close it when labeling of the main pool ends.
Smart mixing is set up when you upload tasks to the pool. After creating a pool, click Upload and select the method for generating task suites. You can upload them using separate files or one file, arranging them in any order.
Yes, you can do that. In this case, create the first pool based on the training pool and the exam pool based on your main pool. If a pool contains only control and/or training tasks, the price can be set to zero.
In the exam pool, you can create a skill reflecting the exam result and granting admission to the main pool. For example,
if the number of responses is ≥ 10, set the skill value in the <exam skill> as % of correct responses. In your exam pool user requirements, specify:
<exam skill> < 80 or = Is missing>. In the main pool, set up a filter:
<exam skill> >= 80 and (<main skill> >= 70 or = Is missing). You can choose the skill values depending on how well the Tolokers handle your task.
Technically, if you have only one task in your training pool, you don't have this option. The skill will be either
100. We recommend that you add several tasks, or at least 2 so that the Toloker will practice on the first task and will be able to do the second task correctly. In this case, you can admit users to your main pool starting from the skill value of
You can also create a training pool based on the main pool. Assign a skill using the Control tasks rule: in this case, you can admit u