diff --git a/js/statements/abstractStatementModel.js b/js/statements/abstractStatementModel.js
index fb412d2..06d8f4c 100644
--- a/js/statements/abstractStatementModel.js
+++ b/js/statements/abstractStatementModel.js
@@ -1,176 +1,176 @@
-define([
-  'core/js/adapt',
-  '../utils'
-], function(Adapt, Utils) {
+import Adapt from "core/js/adapt";
+import Utils from "../utils";
 
-  var AbstractStatementModel = Backbone.Model.extend({
+export default class AbstractStatementModel extends Backbone.Model {
 
-    defaults: {
+  defaults() {
+    return {
       recipeLang: 'en',
       lang: 'en',
       activityId: null,
       registration: null,
       revision: null,
+      contentRelease: null,
       actor: null,
       contextActivities: {
         grouping: []
       }
-    },
+    };
+  }
 
-    getData: function(model, state) {
-      const statement = new ADL.XAPIStatement();
-      statement.id = ADL.ruuid();
-      statement.actor = new ADL.XAPIStatement.Agent(this.get('actor'));
-      statement.verb = this.getVerb(model);
-      statement.object = this.getObject(model);
-      statement.context = this.getContext(model, state);
-      statement.timestamp = Utils.getTimestamp();
+  getData(model, state) {
+    const statement = new ADL.XAPIStatement();
+    statement.id = ADL.ruuid();
+    statement.actor = new ADL.XAPIStatement.Agent(this.get('actor'));
+    statement.verb = this.getVerb(model);
+    statement.object = this.getObject(model);
+    statement.context = this.getContext(model, state);
+    statement.timestamp = Utils.getTimestamp();
 
-      return statement;
-    },
+    return statement;
+  }
 
-    getVerb: function(model) {
-      // intentionally empty to be overriden by subclass
-    },
+  getVerb(model) {
+    // intentionally empty to be overriden by subclass
+  }
 
-    getActivityType: function(model) {
-      // intentionally empty to be overriden by subclass
-    },
+  getActivityType(model) {
+    // intentionally empty to be overriden by subclass
+  }
 
-    getObject: function(model) {
-      const object = new ADL.XAPIStatement.Activity(this.getUniqueIri(model));
+  getObject(model) {
+    const object = new ADL.XAPIStatement.Activity(this.getUniqueIri(model));
 
-      const definition = {
-        type: this.getActivityType(model),
-        name: this.getName(model)
-      };
+    const definition = {
+      type: this.getActivityType(model),
+      name: this.getName(model)
+    };
 
-      const extensions = this.getObjectExtensions(model);
+    const extensions = this.getObjectExtensions(model);
 
-      if (!(_.isEmpty(extensions))) definition.extensions = extensions;
+    if (!(_.isEmpty(extensions))) definition.extensions = extensions;
 
-      object.definition = definition;
+    object.definition = definition;
 
-      return object;
-    },
+    return object;
+  }
 
-    getObjectExtensions: function(model) {
-      const extensions = {};
-      const type = model.get('_type');
+  getObjectExtensions(model) {
+    const extensions = {};
+    const type = model.get('_type');
 
-      if (type) extensions['https://adaptlearning.org/xapi/extension/model'] = type;
+    if (type) extensions['https://adaptlearning.org/xapi/extension/model'] = type;
 
-      return extensions;
-    },
+    return extensions;
+  }
 
-    getContext: function(model, state) {
-      const context = {
-        contextActivities: this.getContextActivities(model),
-        extensions: this.getContextExtensions(model, state),
-        language: this.get('lang')
-      };
+  getContext(model, state) {
+    const context = {
+      contextActivities: this.getContextActivities(model),
+      extensions: this.getContextExtensions(model, state),
+      language: this.get('lang')
+    };
 
-      const registration = this.get('registration');
-      if (registration) context.registration = registration;
+    const registration = this.get('registration');
+    if (registration) context.registration = registration;
 
-      const revision = this.get('revision');
-      if (revision) context.revision = revision;
+    const revision = this.get('revision');
+    if (revision) context.revision = revision;
 
-      return context;
-    },
+    return context;
+  }
 
-    getContextActivities: function(model) {
-      const contextActivities = _.clone(this.get('contextActivities'));
-      contextActivities.grouping = this.getContextActivitiesGrouping(model);
+  getContextActivities(model) {
+    const contextActivities = _.clone(this.get('contextActivities'));
+    contextActivities.grouping = this.getContextActivitiesGrouping(model);
 
-      return contextActivities;
-    },
+    return contextActivities;
+  }
 
-    getContextActivitiesGrouping: function(model) {
-      const grouping = this.get('contextActivities').grouping.slice();
+  getContextActivitiesGrouping(model) {
+    const grouping = this.get('contextActivities').grouping.slice();
 
-      grouping.push(this.getCourseContextActivity());
+    grouping.push(this.getCourseContextActivity());
 
-      const modelType = model.get('_type');
-
-      if (modelType && modelType !== 'course') {
-        grouping.push.apply(grouping, this.getContentObjectsContextActivities(model));
-      }
+    const modelType = model.get('_type');
 
-      return grouping;
-    },
-
-    getCourseContextActivity: function() {
-      const object = AbstractStatementModel.prototype.getObject.call(this, Adapt.course);
-      object.definition.type = ADL.activityTypes.course;
+    if (modelType && modelType !== 'course') {
+      grouping.push.apply(grouping, this.getContentObjectsContextActivities(model));
+    }
 
-      return object;
-    },
+    return grouping;
+  }
 
-    getContentObjectsContextActivities: function(model) {
-      const contentObjects = model.getAncestorModels(true).filter(function(model) {
-        const modelType = model.get('_type');
-        const isContentObject = modelType === 'menu' || modelType === 'page';
+  getCourseContextActivity() {
+    const object = AbstractStatementModel.prototype.getObject.call(this, Adapt.course);
+    object.definition.type = ADL.activityTypes.course;
 
-        if (isContentObject) return model;
-      });
+    return object;
+  }
 
-      contentObjects.reverse();
+  getContentObjectsContextActivities(model) {
+    const contentObjects = model.getAncestorModels(true).filter(function(model) {
+      const modelType = model.get('_type');
+      const isContentObject = modelType === 'menu' || modelType === 'page';
 
-      const activities = [];
+      if (isContentObject) return model;
+    });
 
-      contentObjects.forEach(function(model) {
-        activities.push(this.getContentObjectContextActivity(model));
-      }, this);
+    contentObjects.reverse();
 
-      return activities;
-    },
+    const activities = [];
 
-    getContentObjectContextActivity: function(model) {
-      const modelType = model.get('_type');
-      const isContentObject = modelType === 'menu' || modelType === 'page';
-      const contentObject = (isContentObject) ? model : model.findAncestor('contentObjects');
-      const object = AbstractStatementModel.prototype.getObject.call(this, contentObject);
-      object.definition.type = ADL.activityTypes.module;
+    contentObjects.forEach(function(model) {
+      activities.push(this.getContentObjectContextActivity(model));
+    }, this);
 
-      return object;
-    },
+    return activities;
+  }
 
-    getContextExtensions: function(model, state) {
-      const buildConfig = Adapt.build;
-      const frameworkVersion = (buildConfig) ? buildConfig.get('package').version : '<3.0.0';
+  getContentObjectContextActivity(model) {
+    const modelType = model.get('_type');
+    const isContentObject = modelType === 'menu' || modelType === 'page';
+    const contentObject = (isContentObject) ? model : model.findAncestor('contentObjects');
+    const object = AbstractStatementModel.prototype.getObject.call(this, contentObject);
+    object.definition.type = ADL.activityTypes.module;
 
-      const extensions = {
-        'https://adaptlearning.org/xapi/extension/framework': 'Adapt',
-        'https://adaptlearning.org/xapi/extension/framework_version': frameworkVersion
-      };
+    return object;
+  }
 
-      return extensions;
-    },
+  getContextExtensions(model, state) {
+    const buildConfig = Adapt.build;
+    const frameworkVersion = (buildConfig) ? buildConfig.get('package').version : '<3.0.0';
+    const specificationRevision = this.get('revision');
+    const contentRelease = this.get('contentRelease');
 
-    getName: function(model) {
-      const name = {};
-      name[this.get('lang')] = model.get('title') || model.get('displayTitle');
+    const extensions = {
+      'https://adaptlearning.org/xapi/extension/framework': 'Adapt',
+      'https://adaptlearning.org/xapi/extension/framework_version': frameworkVersion,
+      'https://adaptlearning.org/xapi/extension/specification_revision': specificationRevision,
+      'https://adaptlearning.org/xapi/extension/content_release': contentRelease
+    };
 
-      return name;
-    },
+    return extensions;
+  }
 
-    getUniqueIri: function(model) {
-      let iri = this.get('activityId');
+  getName(model) {
+    const name = {};
+    name[this.get('lang')] = model.get('title') || model.get('displayTitle');
 
-      if (model && model.get('_type') !== 'course') {
-        iri += '/' + model.get('_id');
-      }
+    return name;
+  }
 
-      return iri;
-    },
+  getUniqueIri(model) {
+    let iri = this.get('activityId');
 
-    getISO8601Duration: function(milliseconds) {
-      return Utils.getISO8601Duration(milliseconds);
+    if (model && model.get('_type') !== 'course') {
+      iri += '/' + model.get('_id');
     }
 
-  });
-
-  return AbstractStatementModel;
+    return iri;
+  }
 
-});
+  getISO8601Duration(milliseconds) {
+    return Utils.getISO8601Duration(milliseconds);
+  }
+}