Trialling and standardisation
The sentence completion, reading comprehension and phonics questions for the New Group Reading Test (NGRT) were developed by English subject experts.
These questions were initially developed for the paper version of NGRT. They were trialled in 2009 using 2,481 students in 73 schools. After the trials seven paper tests were developed for standardisation for students ages 5 to 16 years. The paper standardisation was conducted in the United Kingdom and took place in 2010 using a total of 11,716 students from 476 schools. A further four paper tests were developed and trialled in 2013 using 1,635 students in 34 schools. The standardisation for these new paper tests took place in 2014 using a total of 4,960 students from 187 schools. The reliability of every paper test is above 0.9 which is high. More details of the trial and standardisation of the paper tests are given in the NGRT paper Teacher Guides.
The digital version of NGRT uses the same questions as those in the paper version. Three parallel versions of the standardised tests (Forms A, B and C) were created, with questions of similar levels of difficulties in each form. The individual question statistics, derived from the paper trials and standardisation, were used to map all the reading questions across all the booklets onto a common difficulty scale, and estimates of an overall reading ability were derived for the paper versions of the tests. The standardised scores for the digital version are based on the reading ability scores. Item Response Theory was used to derive the common difficulty scale and model the adaptive method used to select questions in the digital version of the test.