<ul>Estimated completion time:
<li>up to 2 min => very short survey</li>
<li>2-5 min => short survey</li>
<li>5-10 min => medium length survey</li>
<li>10-15 min => long survey</li>
<li>15-30 min => very long survey</li>
<li>30-45 min => extensive survey</li>
<li>more than 45 min => very extensive survey</li>
</ul>