> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-change-1791323909-75c753a.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Example data format
Before diving into this content, it might be helpful to read the following:
* [Conceptual guide on evaluation](/langsmith/evaluation-concepts)
LangSmith stores examples in datasets as follows:
| Field Name | Type | Description |
| - | - | - |
| **id** | UUID | Unique identifier for the example. |
| **name** | string | The name of the example. |
| **created\_at** | datetime | The time this example was created |
| **modified\_at** | datetime | The last time this example was modified |
| **inputs** | object | A map of inputs for the example. |
| **outputs** | object | A map or set of outputs generated by the run. |
| **dataset\_id** | UUID | The dataset the example belongs to |
| **source\_run\_id** | UUID | For examples created from a LangSmith [`Run`](/langsmith/run-data-format), the ID of that run |
| **source\_thread\_id** | string | For examples created from a [thread](/langsmith/observability-concepts#threads) or from a run in a thread, the ID of that thread |
| **metadata** | object | A map of additional, user or SDK defined information that can be stored on an example. |
To learn more about how examples are used in evaluation, read our how-to guide on [evaluating LLM applications](/langsmith/evaluate-llm-application).
The `outputs` field can also hold [assertions](/langsmith/assertions), free-form claims a reviewer wrote about a correct answer. Offline evaluators read them from `reference_outputs["assertions"]`.
***
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