Singular subjects require singular verbs and plural subjects require plural verbs… except when they don’t.
A singular noun. Yes, the origin of the word is the Latin plural of datum, but that’s not the point. Languages are dynamic and changing; if you don’t go with the flow, it can sound hypercorrect.
American spelling uses -ize; British spelling uses either -ize or -ise and may vary from one publication to the next. But be consistent!