Final answer:
Participant reactivity can be reduced by using a variety of methods including time sampling, naturalistic observation, event sampling procedures, and unobtrusive measures. All of these techniques help to minimize the influence of observation on participant behavior.
Step-by-step explanation:
Participant reactivity can be reduced by a) Using Time Sampling Procedures, b) Using Naturalistic Observation, c) Using Event Sampling Procedures, and d) Using Unobtrusive Measures. The correct answer is e) All of the Above. Participant reactivity refers to the changes in behavior or responses of study participants when they are aware they are being observed. Each of these methods aims to minimize the influence that the awareness of observation has on participants by blending into the natural environment (naturalistic observation), only observing at specific times or during specific events (time/event sampling), or by collecting data without the direct interference of the researcher (unobtrusive measures).