File size: 2,913 Bytes
0712a97
d414210
94cf687
 
0712a97
 
94cf687
 
 
 
 
 
 
9516e66
0712a97
 
d414210
86b3b93
d414210
86b3b93
d414210
94cf687
d414210
94cf687
d414210
94cf687
 
0712a97
4cce56e
 
0712a97
94cf687
0712a97
 
a25b32d
 
 
0712a97
 
 
94cf687
 
 
d414210
 
94cf687
 
d414210
94cf687
 
 
 
 
 
 
 
 
 
d414210
94cf687
d414210
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
---
license: apache-2.0
language:
- en
base_model:
- Qwen/Qwen3-4B
pipeline_tag: text-ranking
tags:
- finance
- legal
- code
- stem
- medical
library_name: sentence-transformers
---

<img src="https://i.imgur.com/oxvhvQu.png"/>

# Releasing zeroentropy/zerank-1-small

In search enginers, [rerankers are crucial](https://www.zeroentropy.dev/blog/what-is-a-reranker-and-do-i-need-one) for improving the accuracy of your retrieval system.

This 1.7B reranker is the smaller version of our flagship model [zeroentropy/zerank-1](https://huggingface.co/zeroentropy/zerank-1). Though the model is over 2x smaller, it maintains nearly the same standard of performance, continuing to outperform other popular rerankers, and displaying massive accuracy gains over traditional vector search.

We release this model under the open-source Apache 2.0 license, in order to support the open-source community and push the frontier of what's possible with open-source models.

## How to Use

```python
from sentence_transformers import CrossEncoder

model = CrossEncoder("zeroentropy/zerank-1-small", trust_remote_code=True)

query_documents = [
    ("What is 2+2?", "4"),
    ("What is 2+2?", "The answer is definitely 1 million"),
]

scores = model.predict(query_documents)

print(scores)
```

The model can also be inferenced using ZeroEntropy's [/models/rerank](https://docs.zeroentropy.dev/api-reference/models/rerank) endpoint.

## Evaluations

NDCG@10 scores between `zerank-1-small` and competing closed-source proprietary rerankers. Since we are evaluating rerankers, OpenAI's `text-embedding-3-small` is used as an initial retriever for the Top 100 candidate documents.

| Task           | Embedding | cohere-rerank-v3.5 | Salesforce/Llama-rank-v1 | **zerank-1-small** | zerank-1 |
|----------------|-----------|--------------------|--------------------------|----------------|----------|
| Code           |    0.678  |       0.724        |           0.694          |      **0.730**     |   0.754  |
| Conversational |    0.250  |       0.571        |           0.484          |      **0.556**     |   0.596  |
| Finance        |    0.839  |       0.824        |           0.828          |      **0.861**     |   0.894  |
| Legal          |    0.703  |       0.804        |           0.767          |      **0.817**     |   0.821  |
| Medical        |    0.619  |       0.750        |           0.719          |      **0.773**     |   0.796  |
| STEM           |    0.401  |       0.510        |           0.595          |      **0.680**     |   0.694  |

Comparing BM25 and Hybrid Search without and with `zerank-1-small`:

<img src="https://cdn-uploads.huggingface.co/production/uploads/67776f9dcd9c9435499eafc8/2GPVHFrI39FspnSNklhsM.png" alt="Description" width="400"/> <img src="https://cdn-uploads.huggingface.co/production/uploads/67776f9dcd9c9435499eafc8/dwYo2D7hoL8QiE8u3yqr9.png" alt="Description" width="400"/>