Tutoring, such like TutorVista, is referred to as e-moderation and facilitation to achieve goals of independent learning, learner autonomy, self-reflection, knowledge construction, collaborative or group-based learning, online discussion, transformative learning and communities of practice (Salmon, 2004;Benson, 2001; Mezirow, 2000; Schon, 1987; Wenger, 1998). These goals of moderation are based on principles of constructivist or social-constructivist principles of learning. E-moderation is a term synonymous with tutoring online. Peer tutoring involves peers within a course/subject tutoring each other for the mutual benefit of learning an area of study. for example, online tutoring in chemistry( you can get Chemistry Problems and  Chemistry Answers @tutorvista). Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, the study of inorganic matter; organic chemistry, the study of organic (carbon based) matter; biochemistry, the study of substances found in biological organisms; physical chemistry, the study of chemical processes using physical concepts such as thermodynamics and quantum mechanics; and analytical chemistry, the analysis of material samples to gain an understanding of their chemical composition and structure. Many more specialized disciplines have emerged in recent years, e.g. neurochemistry the chemical study of the nervous system. sometimes we need Chemistry help in learning chemistry as we need help in Physics help by asking help to Physics problem solver. Physics Problems and Physics Answers are provided by tutorvista and tutoring is available 24X7.