This study examined test takers' perception of assessment demand and its impact on the measurement of intended constructs. More than 800 test takers took a pre- and a posttest of College English Test Band 4 and filled in a perception questionnaire to report the skills they perceive as necessary for answering the test. The study found test takers perceived language skills and test-taking skills as equally necessary. Perception of linguistic knowledge negatively affected performance on the reading test, while perceptions of test-taking skills positively affected performance on the reading test and the essay test. Test takers' perception of assessment seemed to affect the measurement of the intended construct, although the effects are marginal. The study also found instrumentally oriented test takers and test takers with higher starting English ability tend to perceive the test as more demanding, such perception, in turn, contributed to better test performance. (Contains 7 tables and 2 figures.)