Reliance on PhD students to deliver undergraduate tutorials and seminars has - particularly in the US - enabled undergraduate expansion while keeping tuition fees under control ("PhDs told to avoid too much teaching", June 30).
For decades, teaching assistantships have been a source of financial support for PhD students. A benefit for those who've taught is their edge over others in the job market. PhD teaching and research must be balanced, but who is better placed to offer advice than a research-active supervisor?
Martha Young-Scholten
Newcastle University