
<p>Raw GPS-data reflect series of locations rather than activity per se. However, measures of activity can be extracted from these data.</p>
<p>Table <a href="activity.html#tab:GPSfeatures">6.1</a> shows some of the measures that were derived from GPS data in a small (n = 28) study exploring the correlation between passive EMA data and depression, conducted by researchers of Northwestern University <span class="citation">(Saeb et al., <a href="#ref-Saeb2015">2015</a>)</span>. The researchers calculated tot