# Task types


A Campaign can contain several steps. Each step specifies its work, interface, pay unit, and acceptance process. Select the type in the human-work step of Builder.

## Choose a type

Choose a type by answering three questions about the step: what the Contributor is given, what they do, and what they hand in.

| Type | The Contributor is given | They | They hand in |
| --- | --- | --- | --- |
| `source` | A collection brief and quality rules | Provide new material that fits the brief | The files or entries, with any source details you ask for |
| `label` | Existing material and labeling rules | Apply the rules to each item | The chosen label and any required note |
| `evaluate` | Content you supply and the criteria to judge it by | Assess the content against the criteria | A rating or choice, with a reason where required |
| `synthesize` | Source material and a brief | Organize it or write the requested content | The text or file the brief asks for |
| `validate` | An earlier human submission from this Campaign, shown read-only | Decide whether it meets the standard | A valid-or-not judgment |

The rows illustrate how to define a step. They are not a list of tools.

## Evaluate or validate

Use `evaluate` when people judge content you supply, such as rating a set of answers against a rubric. Use `validate` when people check work that another Contributor submitted in an earlier step of the same Campaign.

## Set up the step

**The type does not add a tool.** It names the kind of work. What a Contributor can actually enter comes from the form template, so a `label` step still needs a template with a field for each label you want back. For `source`, `label`, `evaluate`, and `synthesize` steps, configure **Work UI / Form template** as described in [Brief and work form](/tasks/define#brief-and-work-form), then use **Preview** to see what a Contributor will see.

A `validate` step reads the earlier step you select; it does not need a second collection form. Set its reviewer count, agreement threshold, and reward allocation separately in the [workflow](/tasks/workflow).

Contributors should follow the instructions and **Pay** shown for their current step. Steps in the same Campaign can ask for different work and pay under different conditions.