Language standardi[s/z]ation

Which spelling of the second word in this chapter title is correct? ‘standardisation’ or ‘standardization’? Do you think one form is ‘better’ than the other? Would it depend upon who was using the word? Your intuitions on which form is correct/better depend upon attitudes to Standard English, where you acquired English, and perhaps where you now live. Growing up in the US, I would have said the ‘z’ spelling, but after a decade in the UK, I would use ‘s’. The switch was determined by the domain for my language use. It first happened for me when writing for work, as the expectation of the UK audience was to use ‘s’, and eventually this work use spread to all my writing.