# Language regeneration
Regeneration form What? Starting points:
Some semantic representation:
- logical form (early work)
- distributional representations (e.g. paraphrasing)
- hidden states of a neural network
Formally-defined data: databases, knowledge bases
Numerical data: e.g., weather reports.
## Regeneration: transforming text
Tasks that come under regeration are:
- [[Machine Translation]]
- [[Text Summarization]]
- Text simplification
### Subtasks in generation
- Content selection: deciding what information to convey (selecting important or relevant content)
- Discourse structuring: overall ordering
- Aggregation: splitting information into sentence-sized chunks
- Referring expression generation: deciding when to use pronouns, which modifiers to use etc
- Lexical choice: which lexical items convey a given concept
- Realisation: mapping from a meaning representation to a string
- Fluency ranking: discriminate between grammatically / semantically valid and invalid sentences
### Approaches to generation
- Templates: fixed text with slots, fixed rules for content selection.
- Statistical: use machine learning (supervised or unsupervised) for the various subtasks.
- Deep learning: particularly for regeneration tasks.
Large scale dialogue and question answering systems, such as Siri, use a combination of the above techniques.
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## References