Sentence:  Dr. Clark has served as teacher and principal in Oklahoma high schools , as teacher and athletic director at Raymondville , Texas , High School , as an instructor at the University of Oklahoma , and as an <WSD>associate</WSD> professor of education at Fort Hays , Kan. , State College . 
Meaning of the word marked with <WSD> tags:  a teacher lower in rank than a full professor but higher than an assistant professor