Research examining adult tennis players' problem representations accessed during competition is limited to women collegiate varsity and beginner players (McPherson, 1999a, 1999b, 2000). This study extended this line of research to male professionals (n=6) and novices (n=6). During competition, an immediate recall and planning interview (i.e., "What were you thinking about while playing that point?" and "What are you thinking about now?") were conducted between points. Players competed within their respective groups. Player's utterances were analyzed according to a model of protocol structure for tennis. Units of information were identified according to 5 major categories: goal (e.g., "get it over the net"), condition (e.g., "he has a weak return of serve on the backhand side"), action (e.g., "I will hit a volley down the line"), do (e.g., "toss my ball higher") , and regulatory concepts (e.g., "I missed my groundstroke"). Concept content was measured in each major category for total (sum of all concepts) and variety (sum of all subconcept categories). Also, conditions and actions were measured according to 4 levels of sophistication (inappropriate or weak; appropriate-no feature; appropriate-one feature; appropriate-two features; or appropriate-three or more features) and goals were measured according to 3 hierarchical levels (skill-themselves; themselves-opponent; or win attributes). Content association was measured according to 3 linkage categories (one concept; two concepts; or three or more concepts) and total connections (if, so) linking any two concepts. Mann Whitney U tests were conducted on frequency scores for the variables previously presented. Immediate recall interview results indicated professionals accessed significantly more total, varied, and sophisticated condition concepts than novices. Also, novices generated significantly more total and varied do concepts than professionals. Although measures of action concepts did not reach significance, professionals applied actions more consistently than novices. Novices exclusively generated weak or inappropriate conditions and actions. Also, professionals accessed more associated concepts than novices. Planning interview results indicated experts generated significantly more total goals and goals at the skill and themselves level; more total, varied, and sophisticated conditions; and more sophisticated actions than beginners. Novices exclusively generated do concepts and weak conditions and actions. Measures of association indicated professionals generated more connections and double and triple linkages, and fewer single concepts than novices. During competition, novices accessed weak problem representations and at best rudimentary action plan profiles. In contrast, professionals accessed tactical problem representations that included action plan and current event profiles to mediate their response selections during competition.Keyword(s): . NA