When General Certificates of Secondary Education (GCSEs) were introduced in the late 1980s, coursework was included as a requirement in many subjects. Coursework was intended to help best represent students' attainments, but concerns about various issues (e.g., tasks becoming formulaic, authenticity of student work, workload) led to a review and ultimately to its replacement with "controlled assessments". This research investigated the effects of this change. A questionnaire was completed by 346 teachers across 6 subjects. Most teachers felt the risks of plagiarism are similar or have reduced. Two thirds of teachers reported that the introduction of controlled assessment has affected the way they teach, and around 60% feel it has affected the nature of the knowledge and skills learnt by students. There are reportedly practical challenges relating to timetabling, student absence, and increased administration. However, over 70% of teachers consider it "important" or "very important" to have some form of internal assessment in their subject.