# tinyroberta-mrqa

This is the *distilled* version of the [VMware/roberta-large-mrqa](https://huggingface.co/VMware/roberta-large-mrqa) model. This model has a comparable prediction quality to the base model and runs twice as fast.

## Overview
**Language model:** tinyroberta-mrqa  
**Language:** English  
**Downstream-task:** Extractive QA  
**Training data:** MRQA
**Eval data:** MRQA  

## Hyperparameters

### Distillation Hyperparameters
```
batch_size = 96
n_epochs = 4
base_LM_model = "deepset/tinyroberta-squad2-step1"
max_seq_len = 384
learning_rate = 3e-5
lr_schedule = LinearWarmup
warmup_proportion = 0.2
doc_stride = 128
max_query_length = 64
distillation_loss_weight = 0.75
temperature = 1.5
teacher = "VMware/roberta-large-mrqa"
```
### Finetunning Hyperparameters

We have finetuned on the MRQA training set.
```
    learning_rate=1e-5,
    num_train_epochs=3,
    weight_decay=0.01,
    per_device_train_batch_size=16,
    n_gpus = 3
```

## Distillation
This model is inspired by deepset/tinyroberta-squad2. 
We start with a base checkpoint of [deepset/roberta-base-squad2](https://huggingface.co/deepset/roberta-base-squad2) and perform further task prediction layer distillation on [VMware/roberta-large-mrqa](https://huggingface.co/VMware/roberta-large-mrqa).
We then fine-tune it on MRQA. 

## Usage

### In Transformers
```python
from transformers import AutoModelForQuestionAnswering, AutoTokenizer, pipeline

model_name = "VMware/tinyroberta-mrqa"

# a) Get predictions
nlp = pipeline('question-answering', model=model_name, tokenizer=model_name)
QA_input = {
    'question': '',
    'context': ''
}
res = nlp(QA_input)

# b) Load model & tokenizer
model = AutoModelForQuestionAnswering.from_pretrained(model_name)
tokenizer = AutoTokenizer.from_pretrained(model_name)
```

## Performance

We have Evaluated the model on the MRQA dev set and test set using SQUAD metrics. 

```
eval exact match: 69.2
eval f1 score: 79.6

test exact match: 52.8
test f1 score: 63.4

```