diff --git a/README.md b/README.md
index 4d359d7..4e43d52 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,106 @@ If you want to load public datasets, try:
 * [huggingface/datasets](https://github.com/huggingface/datasets)
 
 If you want to load local, personal dataset with minimized boilerplate, use **Smile Dataset**!
+
+## Support Matrix
+
+| task                   | supported  | core abstractions |
+|:-----------------------|:-----------|:------------------|
+| question answering     | [x]        | `ExampleForQuestionAnswering`, `DatasetForQuestionAnswering`, `DatapipeForQuestionAnswering`|
+| masked language model  | [x]        | `ExampleForMaskedLanguageModel`, `DatasetForMaskedLanguageModel`, `DatapipeForMaskedLanguageModel`|
+| sequence classification| [x]        | `ExampleForSequenceClassification`, `DatasetForSequenceClassification`, `DatapipeForSequenceClassification`|
+| token classification   | [x]        | `ExampleForTokenClassification`, `DatasetForTokenClassification`, `DatapipeForTokenClassification`|
+| unsupervised simcse    | [x]        | `ExampleForUnsupervisedSimCSE`, `DatasetForUnsupervisedSimCSE`, `DatapipeForUnsupervisedSimCSE`|
+| supervised simcse      | [x]        | `ExampleForSupervisedSimCSE`, `DatasetForSupervisedSimCSE`, `DatapipeForSupervisedSimCSE`|
+| hard negative simcse   | [x]        | `ExampleForHardNegativeSimCSE`, `DatasetForHardNegativeSimCSE`, `DatapipeForHardNegativeSimCSE`|
+
+
+## Usage
+
+All datapipes for different tasks has the same interface.
+
+Here is an example for question answering task, but you can use datapipe the same way for other tasks.
+
+### Example for Question Answering
+
+```python
+
+from smile_datasets import DatasetForQuestionAnswering, DatapipeForQuestionAnswering
+
+
+train_input_jsonl_files = ["data/train.jsonl"]
+train_dataset = DatapipeForQuestionAnswering.from_jsonl_files(
+    input_files=train_input_jsonl_files, 
+    vocab_file="bert/vocab.txt",
+    batch_size=32,
+)
+
+# check dataset
+print(next(iter(train_dataset)))
+
+# model = build_keras_model(...)
+# model.compile(...)
+# train model
+model.fit(train_dataset, callbacks=[...])
+
+```
+
+
+For maximum flexibility, you can always subclass `DatasetForQuestionAnswering` to load your dataset, just like `torch.utils.data.Dataset`:
+
+```python
+from smile_datasets import DatasetForQuestionAnswering, DatapipeForQuestionAnswering, ParserForQuestionAnswering
+
+class DuReaderDatasetForQuestionAnswering(DatasetForQuestionAnswering):
+    """Dataset reader for DuReader dataset."""
+
+    def __init__(self, input_files, vocab_file, subset="rubost", **kwargs) -> None:
+        super().__init__()
+        self.parser = ParserForQuestionAnswering(tokenizer=None, vocab_file=vocab_file, **kwargs)
+        if subset == "rubost":
+            self.instances = list(readers.read_dureader_rubost(input_files, **kwargs))
+        else:
+            self.instances = list(readers.read_dureader_checklist(input_files, **kwargs))
+        self.examples = []
+        for instance in self.instances:
+            e = self.parser.parse(instance)
+            if not e:
+                continue
+            self.examples.append(e)
+
+    def __len__(self):
+        return len(self.examples)
+
+    def __getitem__(self, index) -> ExampleForQuestionAnswering:
+        return self.examples[index]
+
+
+dataset = MyDatasetForQuestionAnswering(input_files=["data/trian.jsonl"], vocab_file="bert/vocab.txt")
+train_dataset = DatapipeForQuestionAnswering.from_dataset(dataset, batch_size=32)
+
+# check dataset
+print(next(iter(train_dataset)))
+
+# model = build_keras_model(...)
+# model.compile(...)
+# train model
+model.fit(train_dataset, callbacks=[...])
+```
+
+For better performance, you can convert examples to `tfrecord` in ahead, and then build datapipe from tfrecord files directly:
+
+```python
+# save dataset in tfrecord format
+dataset.save_tfrecord(output_files="data/train.tfrecord")
+
+# build datapipe from tfrecord files
+train_dataset = DatapipeForQuestionAnswering.from_tfrecord_files(input_files="data/train.tfrecord", batch_size=32)
+
+# check dataset
+print(next(iter(train_dataset)))
+
+# model = build_keras_model(...)
+# model.compile(...)
+# train model
+model.fit(train_dataset, callbacks=[...])
+```