File size: 4,609 Bytes
3af5da7
 
a3643df
 
 
 
749a508
 
10ad6df
eb8c838
10ad6df
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
eb8c838
749a508
 
 
 
 
 
 
 
 
 
 
 
 
 
eb8c838
 
 
 
738289e
749a508
 
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
62
---
license: bigscience-bloom-rail-1.0
language:
- fr
- en
pipeline_tag: sentence-similarity
---

Blommz-560m-retriever

Introducing Bloomz-560m-retriever based on the Bloomz-560m-sft-chat model. This model enables the creation of an embedding representation of text and queries for a retrieval task, linking queries to documents. The model is designed to be cross-language, meaning it is language-agnostic (English/French). This model is ideal for Open Domain Question Answering (ODQA), projecting queries and text with an algebraic structure to bring them closer together.

Training

It is a bi-encoder trained on a corpus of context/query pairs, with 50% in English and 50% in French. The language distribution for queries and contexts is evenly split (1/4 French-French, 1/4 French-English, 1/4 English-French, 1/4 English-English). The learning objective is to bring the embedding representation of queries and associated contexts closer using a contrastive method. The loss function is defined as [rr]:

Benchmark

Based on the SQuAD evaluation dataset (comprising 6000 queries distributed over 1200 contexts grouped into 35 themes), we compare the performance in terms of the average top contexter value for a query, the standard deviation of the average top, and the percentage of correct queries within the top-1, top-5, and top-10. We compare the model with a TF-IDF trained on the SQuAD train sub-dataset, DistilCamemBERT, Sentence-BERT, and finally our model. We observe these performances in both monolingual and cross-language contexts (query in French and context in English).

 Model (FR/FR)                                                                                        | Top-mean | Top-std | Top-1 (%) | Top-5 (%) | Top-10 (%) |
|-----------------------------------------------------------------------------------------------------|----------|:-------:|-----------|-----------|------------|
| TF-IDF                                                                                              | 128      | 269     | 23        | 46        | 56         |
| [CamemBERT](https://huggingface.co/camembert/camembert-base)                                        | 417      | 347     | 1         | 2         | 3          |
| [Sentence-BERT](https://huggingface.co/sentence-transformers/paraphrase-multilingual-mpnet-base-v2) | 11       | 41      | 43        | 71        | 82         |
| Bloomz-560m-retriever                                                                               | 10       | 47      | 51        | 78        | 86         |
| Bloomz-3b-retriever                                                                                 | 9        | 37      | 50        | 79        | 87         |

Model (EN/FR)                                                                                        | Top-mean | Top-std | Top-1 (%) | Top-5 (%) | Top-10 (%) |
|-----------------------------------------------------------------------------------------------------|----------|:-------:|-----------|-----------|------------|
| TF-IDF                                                                                              | 607      | 334     | 0         | 0         | 0         |
| [CamemBERT](https://huggingface.co/camembert/camembert-base)                                        | 432      | 345     | 0         | 1         | 1          |
| [Sentence-BERT](https://huggingface.co/sentence-transformers/paraphrase-multilingual-mpnet-base-v2) | 12       | 47      | 44        | 73        | 83         |
| Bloomz-560m-retriever                                                                               | 10       | 44      | 49        | 77        | 86         |
| Bloomz-3b-retriever                                                                                 | 9        | 38      | 50        | 78        | 87         |


How to Use Blommz-560m-retriever

The following example utilizes the API Pipeline of the Transformers library.

```python
import numpy as np
from transformers import pipeline
from scipy.spatial.distance import cdist

retriever = pipeline('feature-extraction', 'cmarkea/bloomz-560m-retriever')
infer = lambda x: [ii[0][-1] for ii in retriever(x)]

list_of_contexts = [...]
emb_contexts = np.concatenate(infer(list_of_contexts), axis=0)
list_of_queries = [...]
emb_queries = np.concatenate(infer(list_of_queries), axis=0)

dist = cdist(emb_queries, emb_contexts, 'euclidean')
top_k = lambda x: [
    [list_of_contexts[qq] for qq in ii]
    for ii in dist.argsort(axis=-1)[:,:x]
]
# top 5 nearest contexts for each queries
top_contexts = top_k(5)
```