What historical sources do you have on early literacy attainment?
We have a number of special collections that may be useful for your research. A description of these collections is available at http://libguides.ioe.ac.uk/specialcollections. In particular, we would recommend you consider the History of Education Collection.
In addition, there are some useful links and descriptions of sources on the Literacy Attainment LibGuide which has been created by Professor Gemma Moss of the Institute of Education.