Compostable Material

I'm starting an experiment today.

The question was posed: Are the claims of degradation of plastic alternatives justified?  Do they biodegrade as efficiently as they claim?

Today this bag has gone into my compost dalek, along with the usual kitchen vegetable waste.  I will leave all alone for three months when I will make my first check on progress. 

A few notes:

This was promoted as a people's science experiment but after volunteering I have heard nothing further from the organisers, so I am doing this off my own bat.

Biodegradability is different from home compostability and isn't on its own a cure for all aspects of the recycling problem - see the thought provoking article here  

I have been caught out before, most notably with teabags, which it turns out have a plastic element (glue?) to them.  Worse still the seemingly "paper" sachets some come in turn out to be plasticised and turn up years later when harvesting potatoes.