An aptitude test requiring 10-minutes' administration time was administered to high school students learning Forkner, Century 21, and Gregg shorthand for the purpose of determining test validity for different shorthand systems. Validity data were obtained from approximately 2000 students. Aptitude test reliability ranged from KR20=0.88 to 0.90. Validity coefficients with shorthand dictation achievement ranged from r=0.44 to 0.55. Because of significant differences in student achievement with different shorthand systems, the aptitude test may be used along with other student background information to assist students and teachers in choosing among alternative shorthand systems. The Lambrecht Shorthand Aptitude Test (LSAT) Test Booklet is appended to the Teacher's Manual. The Teacher's Manual contains the following six sections: (1) Purpose of the LSAT; (2) Administering the LSAT; (3) Scoring the LSAT; (4) Interpreting LSAT scores; (5) Technical Data from Three Validations Studies; and (6) Collecting Other Validity Data. (Author/RL)