The feasibility of a self-scoring flexilevel test was investigated in terms of practical effectiveness and criterion related validity. The test was administered to over 2,000 students studying secondary school mathematics in Thailand. The study was conducted, and the test administered, in two phases: test development and evaluation. The test was designed to measure a single ability and the items were multiple choice. A large item bank was used in order to spread item difficulty values over a wide range and to have a constant distance between item difficulty values. Results indicated that the self-scoring flexilevel test had a criterion related validity of .7238. This was statistically significant and different from the validity coefficient (.6109) of the comparative conventional test. Results of an attitude measure indicated that the students had a favorable impression of the self-scoring flexilevel test. It was concluded that this type of test is effective and practical. (GDC)