I received this message last week:
"I am trying to find a book to buy written in ITA. I learned ITA at school from 1965 to about 1968. I think it must have been pretty new then because when I went up to the junior school, there were only 6 of us who read ITA. They had to split the class and write everthing twice, once in ITA and again in English"
Yes, it was a very odd period in British education - a really mad-cap idea that was dominant for several years and then dropped rapidly from favour. Although I was born in 1964 so must be a bit younger than you, I managed to escape ITA, although my cousins (about 6 years younger than me and so learning to read in the early 70s, were taught using ITA and still blame it to this day for their problems with spelling! So that would span about a decade.
If you have no idea what ITA is - and many people look completely blank if I mention it - this picture above should give you an idea.
Ladybird were only following a widespread initiative in issuing books in the ITA alphabet; I remember most children's publishers doing the same.
As I say, I had always thought of ITA as an experiment of the early 1970s and considered that my cousins were 'hit' with ITA as a result of being that bit younger than me. But clearly this correspondent was a little older than me and she was taught to ITA. That must be the case, thinking about it, because I have heard of Ladybird books in ITA with dustwrappers - so earlier than 1965.
So what dictated the decision to adopt ITA? Why did some schools adopt it and others did not over quite a number of years? And why did it sink so quickly and almost without a trace? If anyone knows, do get in touch.