diff --git a/app/controllers/discussion_topics_controller.rb b/app/controllers/discussion_topics_controller.rb
index 77541d13efe..6946d7962f0 100644
--- a/app/controllers/discussion_topics_controller.rb
+++ b/app/controllers/discussion_topics_controller.rb
@@ -48,6 +48,7 @@ class DiscussionTopicsController < ApplicationController
   # @response_field topic_children An array of topic_ids for the group discussions the user is a part of
   # @response_field user_name The username of the creator
   # @response_field url The URL to the discussion topic in canvas
+  # @response_field discussion_type The type of discussion. Values are 'side_comment', for discussions that only allow one level of nested comments, and 'threaded' for fully threaded discussions.
   # @response_field permissions[attach] If true, the calling user can attach files to this discussion's entries.
   #
   # @example_response
@@ -68,6 +69,7 @@ class DiscussionTopicsController < ApplicationController
   #        "topic_children":[],
   #        "root_topic_id":null,
   #        "podcast_url":"/feeds/topics/1/enrollment_1XAcepje4u228rt4mi7Z1oFbRpn3RAkTzuXIGOPe.rss",
+  #        "discussion_type":"side_comment",
   #        "attachments":[
   #          {
   #            "content-type":"unknown/unknown",
diff --git a/app/models/discussion_topic.rb b/app/models/discussion_topic.rb
index 6df78620046..a2ca7d1c5fa 100644
--- a/app/models/discussion_topic.rb
+++ b/app/models/discussion_topic.rb
@@ -26,7 +26,13 @@ class DiscussionTopic < ActiveRecord::Base
 
   attr_accessible :title, :message, :user, :delayed_post_at, :assignment,
     :plaintext_message, :podcast_enabled, :podcast_has_student_posts,
-    :require_initial_post, :threaded
+    :require_initial_post, :threaded, :discussion_type
+
+  module DiscussionTypes
+    SIDE_COMMENT = 'side_comment'
+    THREADED     = 'threaded'
+    TYPES        = DiscussionTypes.constants.map { |c| DiscussionTypes.const_get(c) }
+  end
 
   attr_readonly :context_id, :context_type, :user_id
 
@@ -48,6 +54,7 @@ class DiscussionTopic < ActiveRecord::Base
   belongs_to :user
   validates_presence_of :context_id
   validates_presence_of :context_type
+  validates_presence_of :discussion_type, :in => DiscussionTypes::TYPES
   validates_length_of :message, :maximum => maximum_long_text_length, :allow_nil => true, :allow_blank => true
   validates_length_of :title, :maximum => maximum_string_length, :allow_nil => true
 
@@ -65,9 +72,22 @@ class DiscussionTopic < ActiveRecord::Base
   after_create :create_participant
   after_create :create_materialized_view
 
+  def threaded=(v)
+    self.discussion_type = Canvas::Plugin.value_to_boolean(v) ? DiscussionTypes::THREADED : DiscussionTypes::SIDE_COMMENT
+  end
+
+  def threaded?
+    self.discussion_type == DiscussionTypes::THREADED
+  end
+
+  def discussion_type
+    read_attribute(:discussion_type) || DiscussionTypes::SIDE_COMMENT
+  end
+
   def default_values
     self.context_code = "#{self.context_type.underscore}_#{self.context_id}"
     self.title ||= t '#discussion_topic.default_title', "No Title"
+    self.discussion_type = DiscussionTypes::SIDE_COMMENT if !read_attribute(:discussion_type)
     @content_changed = self.message_changed? || self.title_changed?
     if self.assignment_id != self.assignment_id_was
       @old_assignment_id = self.assignment_id_was
@@ -106,7 +126,7 @@ class DiscussionTopic < ActiveRecord::Base
       topic.title = "#{self.title} - #{group.name}"
       topic.assignment_id = self.assignment_id
       topic.user_id = self.user_id
-      topic.threaded = self.threaded
+      topic.discussion_type = self.discussion_type
       topic.save if topic.changed?
       topic
     end
diff --git a/app/views/shared/_topic.html.erb b/app/views/shared/_topic.html.erb
index 9e2e545ad0f..3f979648455 100644
--- a/app/views/shared/_topic.html.erb
+++ b/app/views/shared/_topic.html.erb
@@ -119,7 +119,7 @@
       <span class="podcast_enabled"><%= (topic && topic.podcast_enabled) ? "1" : "0" %></span>
       <span class="podcast_has_student_posts"><%= (topic && topic.podcast_has_student_posts) ? "1" : "0" %></span>
       <span class="require_initial_post"><%= (topic && topic.require_initial_post) ? "1" : "0" %></span>
-      <span class="threaded"><%= (topic && topic.threaded) ? "1" : "0" %></span>
+      <span class="threaded"><%= topic.try(:threaded?) ? "1" : "0" %></span>
     </div>
   </div>
 </div>
diff --git a/db/migrate/20120328162105_add_discussion_topic_type.rb b/db/migrate/20120328162105_add_discussion_topic_type.rb
new file mode 100644
index 00000000000..30cfb59451d
--- /dev/null
+++ b/db/migrate/20120328162105_add_discussion_topic_type.rb
@@ -0,0 +1,13 @@
+class AddDiscussionTopicType < ActiveRecord::Migration
+  tag :predeploy
+
+  def self.up
+    remove_column :discussion_topics, :threaded
+    add_column :discussion_topics, :discussion_type, :string
+  end
+
+  def self.down
+    remove_column :discussion_topics, :discussion_type
+    add_column :discussion_topics, :threaded, :boolean
+  end
+end
diff --git a/lib/api/v1/discussion_topics.rb b/lib/api/v1/discussion_topics.rb
index 20516a088c5..52f96e15162 100644
--- a/lib/api/v1/discussion_topics.rb
+++ b/lib/api/v1/discussion_topics.rb
@@ -45,6 +45,7 @@ module Api::V1::DiscussionTopics
                   :methods => [:user_name, :discussion_subentry_count], }, [:attach]
     ).tap do |json|
       json.merge! :message => api_user_content(topic.message, context),
+                  :discussion_type => topic.discussion_type,
                   :podcast_url => url,
                   :read_state => topic.read_state(user),
                   :unread_count => topic.unread_count(user),
diff --git a/spec/apis/v1/assignments_api_spec.rb b/spec/apis/v1/assignments_api_spec.rb
index 960ad61e89b..7ecd8938dcb 100644
--- a/spec/apis/v1/assignments_api_spec.rb
+++ b/spec/apis/v1/assignments_api_spec.rb
@@ -243,6 +243,7 @@ describe AssignmentsApiController, :type => :integration do
       'url' => "http://www.example.com/courses/#{@course.id}/discussion_topics/#{@topic.id}",
       'attachments' => [],
       'permissions' => { 'attach' => true },
+      'discussion_type' => 'side_comment',
     }
   end
 
diff --git a/spec/apis/v1/discussion_topics_api_spec.rb b/spec/apis/v1/discussion_topics_api_spec.rb
index d3a223b7955..c853fc39269 100644
--- a/spec/apis/v1/discussion_topics_api_spec.rb
+++ b/spec/apis/v1/discussion_topics_api_spec.rb
@@ -95,6 +95,7 @@ describe DiscussionTopicsController, :type => :integration do
                                    "size"=>attachment.size,
                   }],
                   "topic_children"=>[sub.id],
+                  "discussion_type" => 'side_comment',
                   "permissions" => { "attach" => true }}
   end
 
@@ -165,6 +166,7 @@ describe DiscussionTopicsController, :type => :integration do
                           "posted_at"=>gtopic.posted_at.as_json,
                           "root_topic_id"=>nil,
                           "topic_children"=>[],
+                          "discussion_type" => 'side_comment',
                           "permissions" => { "attach" => true }}
   end
 
@@ -826,6 +828,12 @@ describe DiscussionTopicsController, :type => :integration do
     end
 
     context "in the original API" do
+      it "should respond with information on the threaded discussion" do
+        json = api_call(:get, "/api/v1/courses/#{@course.id}/discussion_topics",
+                 { :controller => "discussion_topics", :action => "index", :format => "json", :course_id => @course.id.to_s })
+        json[0]['discussion_type'].should == 'threaded'
+      end
+
       it "should return nested discussions in a flattened format" do
         json = api_call(:get, "/api/v1/courses/#{@course.id}/discussion_topics/#{@topic.id}/entries",
                  { :controller => "discussion_topics_api", :action => "entries", :format => "json", :course_id => @course.id.to_s, :topic_id => @topic.id.to_s })
diff --git a/spec/factories/discussion_topic_factory.rb b/spec/factories/discussion_topic_factory.rb
index e986d4febaf..83295b027b6 100644
--- a/spec/factories/discussion_topic_factory.rb
+++ b/spec/factories/discussion_topic_factory.rb
@@ -40,7 +40,7 @@ end
 def topic_with_nested_replies(opts = {})
   course_with_teacher(:active_all => true)
   student_in_course(:course => @course, :active_all => true)
-  @topic = @course.discussion_topics.create!(:title => "title", :message => "message", :user => @teacher, :threaded => true)
+  @topic = @course.discussion_topics.create!(:title => "title", :message => "message", :user => @teacher, :discussion_type => 'threaded')
   @root1 = @topic.reply_from(:user => @student, :html => "root1")
   @root2 = @topic.reply_from(:user => @student, :html => "root2")
   @reply1 = @root1.reply_from(:user => @teacher, :html => "reply1")
diff --git a/spec/models/discussion_topic_spec.rb b/spec/models/discussion_topic_spec.rb
index cbc7fab1b12..e0a1292cf92 100644
--- a/spec/models/discussion_topic_spec.rb
+++ b/spec/models/discussion_topic_spec.rb
@@ -25,6 +25,17 @@ describe DiscussionTopic do
     @course.discussion_topics.first.message.should eql("<a href=\"#\">only this should stay</a>")
   end
 
+  it "should default to side_comment type" do
+    d = DiscussionTopic.new
+    d.discussion_type.should == 'side_comment'
+
+    d.threaded = '1'
+    d.discussion_type.should == 'threaded'
+
+    d.threaded = ''
+    d.discussion_type.should == 'side_comment'
+  end
+
   it "should update the assignment it is associated with" do
     course_model
     a = @course.assignments.create!(:title => "some assignment", :points_possible => 5)
@@ -248,10 +259,10 @@ describe DiscussionTopic do
     it "should copy appropriate attributes from the parent topic to subtopics on updates to the parent" do
       topic_for_group_assignment
       subtopics = @topic.refresh_subtopics
-      subtopics.each {|st| st.threaded.should be_nil }
-      @topic.threaded = true
+      subtopics.each {|st| st.discussion_type.should == 'side_comment' }
+      @topic.discussion_type = 'threaded'
       @topic.save
-      subtopics.each {|st| st.reload.threaded.should == true }
+      subtopics.each {|st| st.reload.discussion_type.should == 'threaded' }
     end
   end