span class="header-section-number">Chapter 4</span> Data Management</h1>

<p>In a typical EMA study, lots of data are collected. Repeated self-reports, GPS-data, accelerometer data, background demographic data and traditional questionnaire data quickly add up to gigabytes of raw data. Without proper data management, the EMA researcher would drown in these data. Fortunately, R and RStudio are useful aids to prevent this from happening. R is very flexible in the management of multiple data files, and RStudio 