Add default, update docs.

@@ -78,6 +78,17 @@
       },
 
       /**
+       * When `true`, multiple items may be selected at once (in this case,
+       * `selected` is an array of currently selected items).  When `false`,
+       * only one item may be selected at a time.
+       */
+      multi: {
+        type: Boolean,
+        value: false,
+        observer: '_resetSelection'
+      },
+
+      /**
        * When `multi` is true, this is an array that contains any selected.
        * When `multi` is false, this is the currently selected item, or `null`
        * if no item is selected.
@@ -94,16 +105,6 @@
       toggle: {
         type: Boolean,
         value: false
-      },
-
-      /**
-       * When `true`, multiple items may be selected at once (in this case,
-       * `selected` is an array of currently selected items).  When `false`,
-       * only one item may be selected at a time.
-       */
-      multi: {
-        type: Boolean,
-        observer: '_resetSelection'
       }
     },
 
@@ -128,6 +129,13 @@
       }
     },
 
+    /**
+     * Returns whether the item is currently selected.
+     *
+     * @method isSelected
+     * @param {*} item Item from `items` array to test
+     * @return {boolean} Whether the item is selected
+     */
     isSelected: function(item) {
       if (this.multi) {
         return this._selectedColl.getKey(item) !== undefined;
@@ -138,6 +146,9 @@
 
     /**
      * Deselects the given item if it is already selected.
+     *
+     * @method isSelected
+     * @param {*} item Item from `items` array to deselect
      */
     deselect: function(item) {
       if (this.multi) {
@@ -156,6 +167,9 @@
     /**
      * Selects the given item.  When `toggle` is true, this will automatically
      * deselect the item if already selected.
+     *
+     * @method isSelected
+     * @param {*} item Item from `items` array to select
      */
     select: function(item) {
       var icol = Polymer.Collection.get(this.items);