BBBT Analysis - Spelling
This verbal subtest has 20 items. Only 1 of them is obviously bad. I quickly analysed 96 scores by native English speakers using first attempt only. The reliability is 0.77 and the average corrected item-total correlation is 0.32. The mean was 10.45/20 and the SD was 3.8.
The reliability could be increased by:
Selecting the best items from a large pool. So far there has been 20 items selected from a pool of 21.
Making the test easier. For optimal discrimination the average for r/CT should be closer 14/20.
Administering the subtest to an average IQ audience, since reliability falls as IQ increases.
If these were accomplished the reliability should increase to around 0.84, which is good for a 20-item test. All things considered it is a fine concept and a decent subtest, although it could be improved. Next up is subtest inter-correlation matrix and FSIQ reliability analysis.
Big Beautiful Brain Test is HERE.
