Carrying on from my post last week about spelling variations of names—particularly surnames—it is worth considering why a name might be written differently than what might be expected.
Phonetic spellings
On many occasions, it wasn’t even our ancestors who wrote their names down. The name would have been said to a scribe, and the said scribe would have been the one who wrote the name down. For example, if a couple wed at a church, the bride and groom would have spoken their names and then those would have been written in the register by the official conducting the ceremony. From 1754 in England and Wales, the bride and groom should have signed their names, but you will often find that these were simply crosses, described as their marks, i.e. they couldn’t write their names. On many occasions, they wouldn’t know how to read their names either, and so would have no idea if the name was written “wrongly”.
A local scribe, marrying a local couple, would probably have a better idea of how the name was written than if one of the parties were from further away. The different accent and unfamiliarity to locally occurring names means that if an ancestor moved a long way that the variations can be quite extreme, or may have been modified into a name that the scribe was more familiar with. A non-local accent could also change what the scribe thought they heard.
Copying or transcription errors.
This happens when someone couldn’t read what was originally written and so an error was introduced. That someone might be a modern transcriber or indexer, trying to make the best out of a poor quality image or damaged document. This is what often occurs with indexes and why you should always look at the original document rather than relying on an index. The copying error might have happened much closer to the event. For example, what we see today for censuses prior to 1911, aren’t the original forms completed by our ancestors, but they are compiled lists created by the enumerators from the said forms. Whenever something is copied, errors can be introduced.
There are of course of reasons too, but the above probably cover in excess of 80% of name variation occurrences, at least for non-permanent and not deliberate changes.