DescriptionSocial facilitation is the oldest experimental concept in social psychology. Throughout decades of social facilitation research, social presence has typically been viewed as a dichotomous variable which affects individuals while performing a task. However, this dissertation attempts to investigate whether social presence may be viewed as continuous variable, differing on the salience of presence. In addition, it seeks to determine whether changes in performance can be elicited by prior social presence (residual presence) and the expectation of future social presence (anticipatory presence). Study 1 compared the effects of 6 different levels of presence (absence, artificial presence, passive presence, implied presence, embodied presence, and active presence) on simple and complex task performance. It provides evidence that the various levels of social presence did have a differential impact on participants. From the questionnaire responses, social presence was able to be classified into three distinct categories: low (absence, artificial and passive presence), intermediate (implied presence), and high salience (embodied and active presence). Study 1 also provides some support for the expectation that presence results in simple task facilitation. However, instead of an expected linear relationship between salience of presence and simple task enhancement, a quadratic inverted U-shaped curve was observed. Implied presence, a type of presence of intermediate salience, produced the strongest effects. Study 2 showed that social presence can enhance simple task performance even after the stimulus has been removed (residual presence). Study 2 also provided some indication that anticipating a supervisor could cause social facilitation effects even before the supervisor’s arrival. Questionnaire responses showed that participants expecting the presence of a supervisor, like those exposed to residual presence, were more affected on perceived distraction, immediacy, impact, and stress compared to control participants. Implications of the present results provide the rationale for a modified conceptualization of social facilitation.