sections/finetuning.md

### Fine-tuning

**Dataset**

For fine-tuning, we use the [VQA 2.0](https://visualqa.org/) dataset - particularly, the `train` and `validation` sets. We translate all the questions into the four languages specified above using language-specific MarianMT models. This is because MarianMT models return better labels and are faster, hence, are better for fine-tuning. We get 4x the number of examples in each subset.

**Model**

We use the `SequenceClassification` model as reference to create our own sequence classification model. In this, a classification layer is attached on top of the pre-trained BERT model in order to performance multi-class classification. 3129 answer labels are chosen, as is the convention for the English VQA task, which can be found [here](https://github.com/gchhablani/multilingual-vqa/blob/main/answer_mapping.json). These are the same labels used in fine-tuning of the VisualBERT models. The outputs shown here have been translated using the [`mtranslate`](https://github.com/mouuff/mtranslate) Google Translate API library. Then we use various pre-trained checkpoints and train the sequence classification model for various steps.