Update README.md

README.md

@@ -12,14 +12,18 @@ tags:
 - openlibrary
 pretty_name: Open Library Public Domain Books (English)
 ---
-## Open Library Public Domain Books (English)
+# Open Library Public Domain Books (English)
 
 This dataset contains more than 650,000 public domain books in English digitized by the [Internet Archive](https://archive.org/details/books) as part of the [Open Library](https://openlibrary.org/) project. The dataset was compiled by [Sebastian Majstorovic](https://www.storytracer.org).
 
-### Dataset summary
+## Dataset summary
 
-The dataset contains 653,983 texts (~ 200 million pages) from various collections of the Internet Archive (IA). Texts stored in the Internet Archive that are considered to be books have an associated record in the Open Library catalogue. Only texts with an OL record have been included in this dataset.
+The dataset contains 653,983 OCR texts (~ 200 million pages) from various collections of the Internet Archive (IA). Texts stored in the Internet Archive that are considered to be books have an associated record in the Open Library (OL) catalogue. Only texts with an OL record have been included in this dataset.
 
 In order to find public domain books, the dataset was curated using two approaches:
-1. Identify and download IA collections that are specified to be entirely in the public domain, e.g. the [Cornell University Library](https://archive.org/details/cornell/about?tab=about) collection.
-2. Use the `possible-copyright-status` query parameter to search for the status `NOT_IN_COPYRIGHT` using the IA [Search API](https://archive.org/help/aboutsearch.htm).
+1. Identify and download IA collections that exclusively contain public domain materials, e.g. the [Cornell University Library](https://archive.org/details/cornell/about?tab=about) collection.
+2. Use the `possible-copyright-status` query parameter to search for the status `NOT_IN_COPYRIGHT` across all IA collections using the IA [Search API](https://archive.org/help/aboutsearch.htm).
+
+## Metadata
+
+The book texts are accompanied by basic metadata fields such as title, author and publication year (see [Data Fields](#data-fields) below), as well as IA and OL identifiers. The metadata can be expanded to include more information about e.g. subjects, authors or the files, by using the [OL Books API](https://openlibrary.org/dev/docs/api/books) or [OL Bulk Data Dumps](https://openlibrary.org/developers/dumps) and the [IA Metadata API](https://archive.org/developers/md-read.html).