“…However, MCS also poses several challenges, including efficient task design and allocation, target participant selection, incentive mechanisms, security and privacy concerns, and ensuring the reliability, trustworthiness, and quality of the collected data. Many of these issues have been addressed in prior research [15], [16], [17], [18], [19], [20]. While early MCS studies have focused on a few very common sensor devices, such as GPS traces and accelerometer readings, more recent efforts include many other types of sensor readings, such as physiological data (e.g., heart rate and calorie burn), behavioral data (e.g., sleep habits, battery recharge patterns, and different types of physical activities), social networking data, and systems information, including scans of Wi-Fi, Bluetooth, and cell radios.…”