diff --git a/src/utils/AppUsage.js b/src/utils/AppUsage.js
index 9131049..0818e10 100644
--- a/src/utils/AppUsage.js
+++ b/src/utils/AppUsage.js
@@ -7,22 +7,35 @@ export default class AppUsage {
         return currentUsage;
     }
     
+    /**
+     * Initialize currentUsage for attaching to Analytics events from
+     * the usage cookie if it is set. currentUsage is blank if the cookie is
+     * not set.
+     */
     static initUsage () {
         const usageCookie = Cookie.get('usage');
-        currentUsage =  usageCookie ? usageCookie + '::' : '';
+        currentUsage =  (usageCookie) ? usageCookie + '::' : '';
     }
     
+    /**
+     * Check whether the App should ask for the usage data (first time launched)
+     * @return {boolean} True if the usage cookie has never been set
+     */
     static askForUsage () {
         var usageCookie = Cookie.get('usage');
         return usageCookie === null;
     }
     
+    /**
+     * Set the usage cookie for tracking Analytics Events
+     * @param {string} kind answer from user to the usage survey (home, school, other, noanswer)
+     */
     static setUsage (kind) {
         if (kind === '') {
             Cookie.set('usage', 'noanswer');
         } else {
             Cookie.set('usage', kind);
         }
-        currentUsage = kind === 'noanswer' ? '' : '_' + kind;
+        currentUsage = (kind === '') ? 'noanswer::' : kind + '::';
     }
 }