---
# pretty_name: "" # Example: "MS MARCO Terrier Index"
tags:
- pyterrier
- pyterrier-artifact
- pyterrier-artifact.sparse_index
- pyterrier-artifact.sparse_index.pisa
task_categories:
- text-retrieval
viewer: false
---

# webis-touche2020.pisa

## Description

A PISA index for the Touche2020 dataset (version 2)

## Usage

```python
# Load the artifact
import pyterrier as pt
index = pt.Artifact.from_hf('pyterrier/webis-touche2020.pisa')
index.bm25() # returns a BM25 retriever
```

## Benchmarks

| name   |   nDCG@10 |   R@1000 |
|:-------|----------:|---------:|
| bm25   |    0.6563 |   0.7163 |
| dph    |    0.6785 |   0.7292 |

## Reproduction

```python
import pyterrier as pt
from tqdm import tqdm
import ir_datasets
from pyterrier_pisa import PisaIndex
index = PisaIndex("webis-touche2020/v2.pisa", threads=16)
dataset = ir_datasets.load('beir/webis-touche2020/v2')
docs = ({'docno': d.doc_id, 'text': '{title}\n{text}'.format(**d._asdict())} for d in tqdm(dataset.docs))
index.index(docs)
```

## Metadata

```
{
  "type": "sparse_index",
  "format": "pisa",
  "package_hint": "pyterrier-pisa",
  "stemmer": "porter2"
}
```