# Prepare Training Data#

Finetuner accepts training data and evaluation data in the form of DocumentArray objects. Because Finetuner follows a supervised-learning scheme, you should assign a label to each Document inside your DocumentArray. For most of the models, this is done by adding a fintuner_label tag to each document. Only for cross-modality (text-to-image) fine-tuning with CLIP, this is not necessary as explained at the bottom of this section.

In the code blocks below, you can see examples which demonstrate how the training datasets should look like:

from docarray import Document, DocumentArray

train_da = DocumentArray([
Document(
content='pencil skirt slim fit available for sell',
tags={'finetuner_label': 'skirt'}
),
Document(
content='stripped over-sized shirt for sell',
tags={'finetuner_label': 't-shirt'}
),
...,
])

from docarray import Document, DocumentArray

train_da = DocumentArray([
Document(
uri='https://...skirt-1.png',
tags={'finetuner_label': 'skirt'},
),
Document(
uri='https://...t-shirt-1.png',
tags={'finetuner_label': 't-shirt'},
),
...,
])

from docarray import Document, DocumentArray

train_da = DocumentArray([
Document(
chunks=[
Document(
content='pencil skirt slim fit available for sell',
modality='text',
),
Document(
uri='https://...skirt-1.png',
modality='image',
),
],
),
Document(
chunks=[
Document(
content='stripped over-sized shirt for sell',
modality='text',
),
Document(
uri='https://...shirt-1.png',
modality='image',
),
],
),
])


As was shown in the above code blocks, when fine-tuning a model with a single modality (e.g. image), you only need to create a Document with content and tags with the finetuner_label.

For cross-modality (text-to-image) fine-tuning with CLIP, you should create a root Document which wraps two chunks with the image and text modality. The image and text form a pair. During the training, CLIP learns to place documents that are part of a pair close to each other and documents that are not part of a pair far from each other. As a result, no further labels need to be provided.

Evaluation data should be created in the same way as the training data in the examples above.

CLIP model explained

OpenAI CLIP model wraps two models: a vision transformer and a text transformer. During fine-tuning, we’re optimizing two models in parallel.

At the model saving time, you will discover, we are saving two models to your local directory.

If you need to evaluate metrics on separate evaluation data, it is recommended to create another DocumentArray as above only for evaluation purposes.

Carry on, you’re almost there!