What kind of mistake is represented by the spelling "slideing" for "sliding"?

The spelling "slideing" for "sliding" is a representation of a spelling generalization error. This type of mistake occurs when a learner applies their understanding of spelling patterns to a word but modifies it in a way that reflects a misunderstanding of the specific rules governing that word's spelling.

In this case, the learner likely recognizes a pattern in spelling that allows for the addition of a suffix — typically, while forming the present participle of verbs, an 'e' is often dropped before adding "ing." However, "sliding" does not follow this rule because the base word "slide" ends in an 'e,' requiring it to be dropped when the suffix is added to maintain correct spelling. The learner's application of a general spelling rule led them to incorrectly spell the word, resulting in "slideing" instead of "sliding."

In contrast, a transposition error would involve switching the order of letters, an orthographic error relates specifically to visual representations affecting the ability to spell correctly, and a phonological error would be based on the sound and pronunciation, rather than the rules of spelling.