As part of a package of measures designed to enrich the English language learning environment in Hong Kong schools, the government has recruited up to 700 native-speaking teachers of English (NETs) to join the predominantly non-native speaking Chinese staff teaching English in the local secondary schools. To get an accurate assessment of the operation of the NET scheme, an evaluation project entitled The Monitoring and Evaluation of the Native-speaking English Teacher Scheme (MENETS) was commissioned by a language and research funding body of the government. This large scale research project, involving some 100 schools, employs three major methods to achieve its investigative purposes: assessments, questionnaires, and case studies. In this paper, the presenter will focus on the quantitative measurement of the ESL learners' spoken & written language production before and after increased exposure to a native speaker model.