# Training Data Format

The training data for Rasa NLU is structured into different parts:

- common examples
- synonyms
- regex features and
- lookup tables

While common examples is the only part that is mandatory, including the others will help the NLU model learn the domain with fewer examples and also help it be more confident of its predictions.

## Data Formats

You can provide training data as Markdown or as JSON, as a single file or as a directory containing multiple files. Note that Markdown is usually easier to work with.

### Markdown Format

Markdown is the easiest Rasa NLU format for humans to read and write.
Examples are listed using the unordered list syntax, e.g. minus `-`, asterisk `*`, or plus `+`.
Examples are grouped by intent, and entities are annotated as Markdown links, e.g. `[entity](entity name)`.

```
## intent:check_balance
- what is my balance <!-- no entity -->
- how much do I have on my [savings](source_account) <!-- entity "source_account" has value "savings" -->
- how much do I have on my [savings account](source_account:savings) <!-- synonyms, method 1-->
- Could I pay in [yen](currency)?  <!-- entity matched by lookup table -->

## intent:greet
- hey
- hello

## synonym:savings   <!-- synonyms, method 2 -->
- pink pig

## regex:zipcode
- [0-9]{5}

## lookup:additional_currencies  <!-- specify lookup tables in an external file -->
path/to/currencies.txt
```

The training data for Rasa NLU consists of different sections like common examples, synonyms, regex features, and lookup tables.

### JSON Format

The JSON format consists of a top-level object called `rasa_nlu_data`, with the keys `common_examples`, `entity_synonyms` and `regex_features`.
The most important one is `common_examples`.

```
{
    "rasa_nlu_data": {
        "common_examples": [],
        "regex_features": [],
        "lookup_tables": [],
        "entity_synonyms": []
    }
}
```

### Improving Intent Classification and Entity Recognition

Common examples have three components: `text`, `intent` and `entities`. The first two are strings while the last one is an array.

> - The _text_ is the user message [required]
> - The _intent_ is the intent that should be associated with the text [optional]
> - The _entities_ are specific parts of the text which need to be identified [optional]

### Entity Synonyms

If you define entities as having the same value they will be treated as synonyms. Here is an example of that:

```
## intent:search
- in the center of [NYC](city:New York City)
- in the centre of [New York City](city)
```

To use the synonyms defined in your training data, you need to ensure your pipeline contains the `EntitySynonymMapper` component.