Analysis

Analysis can be very challenging. Not only are speech and language both enormously complex. But children react in their own ways to any attempt to measure those capacities. And, in the limit, the very act of measurement can modify a capacity.

As far as language is concerned, in my view, the most reliable data is from everyday, round the clock observation of the child in the most familiar environment at home.

As far as speech is concerned, the actual process of recording observation requires special training. There is an International Phonetic Alphabet which is much better than English for this purpose. But it can still be difficult to decide which articulators are being used how.

And whatever is being observed, it is necessary to decide how the child is arriving at some particular form.