# Span Based

**Span labeling** projects allow you to label spans of text within a document. This type is well suited for tasks such as named entity recognition ([NER](/data-studio-projects/nlp-task-types/project-templates.md#named-entity-recognition)) and part-of-speech ([POS](/data-studio-projects/nlp-task-types/project-templates.md#part-of-speech)) tagging.

<figure><img src="/files/ct2Jr1jT820WdIlEaqra" alt=""><figcaption></figcaption></figure>

During project creation, you can adjust additional settings as described below.

* **Limit selection to a span of 1 token** is useful when you want to ensure that every token in the document is labeled.
* **Spans should have at most one label** prevents you from adding multiple labels to a single span.
* **Allow arrows to be drawn between labels** lets you draw arrows from one label to another to annotate relationships between words. This is useful for showing that an adjective relates to a noun, or that a pronoun refers to a person.
* **Default text** **selection** lets you choose between token-level or character-level selection. Some languages, such as Mandarin, Korean, or Thai, may require character-level selection.

<figure><img src="/files/CwBXNbcDZKnzRARXI9tu" alt=""><figcaption></figcaption></figure>

**Note**: If you have already created a project, you can change the configurations through [**Project settings**.](/data-studio-projects/lets-get-labeling.md#project-settings)

{% hint style="info" %}
Aside from NER and POS, [audio labeling](/data-studio-projects/nlp-task-types/span-based/audio-project.md) is another type of spanlabeling task. The main difference is that the audio interface displays a waveform and allows you to modify timestamps.
{% endhint %}


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.datasaur.ai/data-studio-projects/nlp-task-types/span-based.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.