Many letters could only be substituted by themselves and all other letters were in some cases substituted by themselves. As a consequence, many words may not have changed at all or only slightly rendering identification easier than in cases with multiple substitutions. Therefore, can the authors tell the percentage of words that were replaced by themselves or very similar strings? Moreover, some substitutions will have resulted in the creation of new valid words (e.g., arc <-> are, bill <-> hill, if <-> it; end <-> and). These cases may have encouraged readers to give incorrect responses. How often did such cases occur?