Trichology Course aimed at practitioners who desire more knowledge about hair but do not want to become fully qualified trichologists. This is offered by home-study but also taught in America and Singapore. A Chinese version of this course is available. Registered members of the IAT can use the letters "IAT" after their name. Members are controlled by a code of ethics. Trichology Trichology is the branch of dermatology that deals with the scientific study of the health of hair and scalp. Trichologists are hair and scalp specialists (one type of skin specialist) who diagnose the causes of hair fall, hair breakage,
The Philadelphia study development to display any social significance. The nearly completed and most advanced changes displayed the most stability within the study and showed intermediate correlation with the middle classes. The new and vigorous changes—the focal point of the study—displayed the strongest curvilinearity and most clearly encompassed the linguistically innovative nature of the inner classes. Through these Results, Labov asserted the truth and significance of what he named the Curvilinear Principle. With the social information gathered from the interviews, he discovered that it is not the education or occupation factors that drove the middle class to spur linguistic change. Rather, it was