When I transferred from modern foreign languages to special educational needs in my secondary school in the mid-1990s, I was recommended to do the Advanced Diploma in Special Needs in Education with the Open University. I enjoyed the course very much, the more so as I could based my assignments on the teaching and learning support I was doing each day in school. The course content brought me up to speed on what were then the priorities of SEN in England, the assignments were appropriately challenging and the method of individual study with telephone conversations and occasional voluntary classes with my tutor all suited me. This said, I don't believe SEN teachers are appointed largely on the basis on the professional development course or university qualification they have completed. I have a couple of Masters degrees and neither of them made any difference career-wise. It's better not to rely overmuch on the perceived relative prestige of qualifications and to concentrate instead on building a portfolio of work that will demonstrate your understanding of good practice with children with SEN and your ability to exploit the SEN provision system to the advantage of the children you teach. I doubt very much that head teachers and other members of appointment panels make their judgments about teaching candidates on the basis of their having attended course X rather than course Y. If you read the messages in the TES SEN forum, you will also see that special schools, where children with the most severe cases of SEN are educated, provide their own in-service training rather than send their new teachers on courses.