This paper describes the validation of actual and preferred forms of a new classroom environment instrument--the Technology-Rich Outcomes-Focused Learning Environment Inventory (TROFLEI)--using multitrait-multimethod modelling. The 80-item TROFLEI assesses 10 classroom environment dimensions: Student Cohesiveness, Teacher Support, Involvement, Investigation, Task Orientation, Cooperation, Equity, Differentiation, Computer Usage and Young Adult Ethos. A sample of 1,249 high school students from Western Australia and Tasmania responded to actual and preferred forms of the TROFLEI. Separate exploratory factor analyses for the actual and preferred forms supported the 10 scale "a priori" structure of the instrument. The use of multitrait-multimethod modelling with the 10 scales as traits and the two forms of the instrument as methods supported the TROFLEI's construct validity. The results of this research provide strong evidence of the sound psychometric properties of this new learning environment instrument. (Contains 7 tables and 1 figure.)