Not so much English during all intermediate lessons.

[kris]

Just a thought. It would be nice if the only English spoken during an intermediate class is the translation of the main conversation and vocabulary. When learning Japanese at a language school English is never spoken in class. I think it would make the podcast a little more fluid and make the listener concentrate harder. Thanks

[Belton]

my 2円

I agree the more Japanese and less English the better.
Chit-chat, asides etc could all be untranslated Japanese, so long as they are mostly using vocabulary and grammar already covered. An attempt could be made to explain grammar and vocabulary usage in Japanese but at Intermediate I think English would still have to be used to explain the core material.

I'm unsure of the point where it becomes feasible to be totally immersive in a passive all audio environment. At what point can you discuss the target language *in* the target language? I'd say that's fairly advanced.

My experience of face to face Japanese classes was immersive / communicative. However it relied a lot on visual aids, acting, roleplay and instant feedback to bridge the understanding gap and teach a grammar point. My teacher was also excellent at gearing down her language to our level. English wasn't used by the teacher (or the students if at all possible.)
Even then there was always a section at the end "Lets speak English and Japanese" where we could confirm and discuss the grammar etc. in English. The higher the level the shorter this section became and the more we were able to discuss Japanese in Japanese. But an intermediate level wasn't that point in our case.

I think this would be harder to do in a podcast, not least because of the lack of visual dimension and lack of instant student - teacher feedback loop.