Angular checkboxes example

Trying to make it work with required

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.4.2/underscore-min.js"></script>
<div ng-controller="myCtrl">
    <form name="myForm" ng-submit="submitSurvey(survey)">
        <span ng-repeat="choice in choices">
            <label class="checkbox">
            <input type="checkbox" required="required" value="{{choice.id}}" ng-change="updateQuestionValues()" ng-model="choice.checked" name="group-one" />
                {{choice.label}}
            </label>
        </span>
        <input type="submit" value="Send" ng-disabled="myForm.$invalid" />
    </form>
    {{value}}
</div>

JavaScript

function myCtrl($scope) {

    $scope.choices = [{
        "id": 1,
        "value": "1",
        "label": "Good"},
    {
        "id": 2,
        "value": "2",
        "label": "Ok"},
    {
        "id": 3,
        "value": "3",
        "label": "Bad"}];

    $scope.value = [];

    $scope.updateQuestionValues = function() {
        $scope.value = _.filter($scope.choices, function(c) {
            return c.checked;
        });
    };
}