Erratum

The original article [1] contains an error whereby the caption of Fig. 2 incorrectly describes respective lines in the associated graph.

Fig. 2
figure 1

Relative precision of a domain score by number of items. Shaded lines vary from correlation between items of 0.40 (black line) to 0.90 (red line)

The article has now been updated so that the caption to Fig. 2 correctly reads as such:

Relative precision of a domain score by number of items. Shaded lines vary from correlation between items of 0.40 (black line) to 0.90 (red line)