Collaborative annotation tools allow you and your students to discuss a text, website, video, or other media through shared marginalia.  It's a form of asynchronous discussion, but instead of taking place within a message board tool (such as D2L Discussions), the conversation happens in comments attached directly on a digital document, web page, or video timeline track.  Better still, each discussion thread - a starting comment and subsequent replies - is keyed to a highlighted word or passage, or a specific time on the video timeline.  

Two collaborative annotation tools are available in all D2L Course Spaces.  

• Hypothes.is
• Perusall

Uses

Both tools serve PDF files to students.  But then each handles media that the other does not.  Here's a breakdown of their various features:

In most cases collaborative annotation should be an engagement or participation grade: incentivize students to read, watch or listen critically, and participate in conversation surrounding media, rather than assessing their performance along a steep grade range.   Keep the stakes low, and try to help students meet some basic learning objectives for critical reading and collaborative analysis, getting full credit in the process.  Some faculty might award a simple pass-fail or contract grade for a given number of reasonably composed comments.  Or, a simple rubric might offer a small grade scale.  Perusall offers a complex automated grading system built mainly to incentivize better work but nevertheless, Perusall counsels instructors to keep grading low-stakes and generous.  

Both Hypothes.is and Perusall offer sample instructions for students, that you can adopt or modify for your own classes.

Example uses, and other resources on pedagogy with Social Annotation

• Hypothes.is: Examples of Classroom Use
• Hypothes.is: 10 Ways to Annotate With Students
• Liquid Margins: A Webcast Show on using Social Annotation (Hypothes.is) to Teach
• Scholarship of Teaching and Learning surrounding Perusall (Collaborative Annotation)