Correction
After publication of our article [1] it has come to our attention that Fig. 3 was accidentally omitted. In the section “Ease of reading”, the sentence “FRE scores were recorded for the original, author-revised and independently edited PES (Fig. 2).” should read “FRE scores were recorded for the original, author-revised and independently edited PES (Fig. 3).” Figure 3 and its legend appear below.