# Hypothesis#

Hypothesis is a centralized web service that allows you to comment and annotate arbitrary web pages across the web. It allows your readers to log in and comment on your book.

Note

Hypothesis is activated on this page. You can see the web overlay by clicking on the < button in the upper-right corner of this page.

## Activate Hypothesis#

You can activate Hypothesis by adding the following to your _conf.yml file:

html: