This is an account of some of the issues raised during 5 years of design, development and operation of the English Language Testing Service (ELTS). The measures in question are made up of five sub-tests: two general tests of reading and listening comprehension, and three modular tests of language study skills in reading, writing, and speaking. The modular tests are in six versions according to the special purpose for which English will be studied. The stages of the work discussed are design, development, operation, and validation. Work in the design stage isolated two major issues: the specification of test content and the different types of test-users. Work in development included overall shape of the test, test realization and pre-testing. The particular issue isolated for discussion in the operation of ELTS is the control of 80 test centers. With regard to on-going evaluation, analyses of test items for each quarter's tests, analyses of sub-test specifications, and validation of profiles (predictive validity) are being carried on. (AMH)