update layout index page
+.. _reports:
+
+=====================================================
+``layout``: Querying BIDS datasets
+=====================================================
+
+.. contents:: **Contents**
+ :local:
+ :depth: 1
+
+|
+
+.. currentmodule:: pybids.layout
+
+.. _loading_datasets:
+
+Loading BIDS datasets
+===========================================
+
+The :obj:`bids.layout.BIDSLayout` class requires the path to a valid BIDS dataset::
+
+ >>> from os.path import join
+ >>> from bids import BIDSLayout
+ >>> from bids.tests import get_test_data_path
+ >>> layout = BIDSLayout(join(get_test_data_path(), 'synthetic'))
+
+The ``BIDSLayout`` instance is a lightweight container for all of the files in the
+BIDS project directory. It automatically detects any BIDS entities found in the
+file paths, and allows us to perform simple but relatively powerful queries over
+the file tree. By default, defined BIDS entities include things like "subject",
+"session", "run", and "type".
+
+.. _querying_datasets:
+
+Querying datasets
+===========================================
+
+Pybids layouts can be queried according to a number of parameters, using
+grabbit's ``get`` functionality.
+
+For example, if we want to get a list of subjects in the dataset::
+
+ >>> layout.get_subjects()
+ ['01', '02', '03', '04', '05']
+
+We can also get a list of all available sessions::
+
+ >>> layout.get_sessions()
+ ['01', '02']
+
+Or a list of tasks::
+
+ >>> layout.get_tasks()
+ ['nback', 'rest']
+
+.. extracting_metadata:
+
+Extracting metadata
+====================
+
+A number of ``BIDSLayout`` methods extract metadata associated with files.
+
+For example, if we want event (task timing) information for a given fMRI scan, we can use ``get_events``::
+
+ >>> f = layout.get(task='nback', run=1, extensions='nii.gz')[0].filename
+ >>> layout.get_events(f)
+
+We can also extract metadata from the json files associated with a scan file::
+
+ >>> f = layout.get(task='nback', run=1, extensions='nii.gz')[0].filename
+ >>> layout.get_metadata(f)
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