optimiSe or optimiZe ?

I agree. Seeing these words end in -ise is strange and alien to me. Here in America they end in -ize.

Ad, are your clients Canadian or international? If they're Canadian, then will they use "-ise" when they search the web? If so, then "-ise" would be better optimized for search engines, wouldn't it? If, on the other hand, your clients are international, then why would you want to use Canadian spelling in the first place? You could always use both versions splayed out all over your website. The search engines would index both. That would look really wacky!

That's the rub, you see. It's a Canadian company, but because it's also a crown corporation, we should be using Canadian spelling standards. The clients are, naturally, international. As we don't use "optimization" in marketing texts, I use the "ise" for client stuff, and "ize" for internal and administrative stuff.

At least my inconsistency is...well, consistent.

From the Canadian Writer's Handbook: "Where alternatives exist, either is correct. But be consistent. In this book . . . we use the ize ending because we believe it to be the dominant form."
I have worked for Canadian newspapers, government agencies and NGOs, and in each place, ize was preferred. Even in Europe, where I now live and work for numerous international organizations, ize is used much more frequently than ise.

In Australia we use -ise, and most grammar schools are quite strict. Many old-fashioned university lecturers will take a dim-view of -ize from a thinly-veiled anti-americanisation perspective. We tend to hold onto our British heritage to demonstrate that we 'know' what we're writing, and don't just let Microsoft spell-check dictate auto-correct -ize!

Ah but alas, TJ, Microsoft too is the creation of a native English speaker...

Porsche,
The suffix ize or even ise or whatever is a weak sister of correct, clear usage.

Some such uses are accepted, but others are considered somewhere between tacky and illiterate.

Finalize was condemned by the Arkansas Gazette (now bought up by the Arkansas Gazette and absorbed out of existence). Old-fashioned writers and editors would write "put into final form" or "complete" or some other longer but more accurate word.

I think a little history lesson might be in order here. Jimmy is on the right track. The -ize ending was universal in ALL English until very recently, only about a hundred years ago. -ize isn't some rampant Americanism. It is the British (and Commonwealth) who diverged from the norm, influenced by the French spellings. That's why there is still resistance to -ise in the UK especially in academic circles.

I think a little history lesson might be in order here. Jimmy is on the right track. The -ize ending was universal in ALL English until very recently, only about a hundred years ago. -ize isn't some rampant Americanism. It is the British (and Commonwealth) who diverged from the norm, influenced by the French spellings. That's why there is still resistance to -ise in the UK especially in academic circles.

A very interesting discussion and what's been said is mostly true. In Britain we do use both ise and ize, and yes ize appears before ise in the OED. I'm also aware that the US spelling uses ize and it's the older form of English, however, I don't know when ise came into use, all I do know is that's how I was taught at school. The reason for both spellings, as I understand it, is the suffix being derived via French -iser from latin -izare and Greek -izein.

I have to say I prefer ise and in my job as proof reader we have that as our house-style. However, we are sometimes forced by some American client companies to use not only ize but all the other American spellings too, even though their products are for the European market which I find extremely irritating - are they trying to sell a product or America?

Was it Churchill who said: "We are are two countries separated by one language" or words to that effect? But to quote the French Vive la diffence!

I always write -ise, with me being English.
Apparently -ize is acceptable here, yet I have actually never seen a case when it has been accepted when seen.

-ize for Americans, -ise for everyone else is the norm...

Belize realise that it's optimise. They don't intellectualize it or dramatize it, they just socialize it.
English language, that compendium of 3 or 4 continental European languages, is constantly evolving & wonderfully adaptive. That boringly inevitable Englishman (or woman) who bobs up uninvited from across the bar or the bus or the table to "correct" Americans, Canadians or Australians, is not the "keeper" of the English language, nor has he (she) ever been. It is simply a case of looking it up in the Macquarie dictionary which says both “ize” and “ise” are perfectly ok.
Nobody outside England (& few inside England) care two hoots what the self-appointed "keepers of the old English language" think ... it's an evolving language and the time to update the Oxford "Dick&Mary" is well past due!

How would you say it out loud? If a 'z' sound comes out of my face then I spell it IZE. (which seems to always be the case). ISE sounds wrong and so, in my book, is wrong.

But I always say: If people didn't make up words we wouldn't have any.

"However, we are sometimes forced by some American client companies to use ... American spellings, even though their products are for the European market ..."

That's rather arrogant of them isn't it. I wonder how they would like it if France labelled all their products destined for the USA in French only. It shows a complete lack of respect.

I'm surprise no one is looking at the Greek root of this. The last letter of the Greek alphabet is the letter s. So, the usage of the letter s instead of the letter z is of Greek origin.

Actually, I take my previous comment back. The last letter of the Greek alphabet is not the letter s.

If the OED says "ize" first, then "ize" it is. It's also "ize" in the US (e.g. Webster's Dictionary of the American Language) except for words like advertise. Apparently someone (at the London Times perhaps) decided to distance him or herself both from America AND from the "official" dictionary at the same time, and this practice has spread....
Personally I wince every time I see someone spelling words like "realise" and "organise" with an "ess" rather than a "zee" not because I'm American, but because I'm English AND American, and I happen to think that this time we Yanks -- immigrant or not) got it right and kept it right.
As to web searching, one would be foolish to ignore the z....

Jim, I'm also glad the yanks kept it right with imperial measurements too :)

Somebody said it earlier. The Oxford English Dictionary (for whom I used to work), accepts both forms but gives 'ize' preference in UK English. I have no idea how 'ise' crept into modern teaching in UK (and Australian) schools. The problem now is that Word believes that 'ise' is British.

Strictly, strictly speaking, educated writing everywhere should use 'ize' - but we have a changing situation where people think it's British to use 'ise'

Just to add to the discussion - I'm Canadian and finished university there, and I NEVER used -ise. Hardly ever saw it either. -ize is definitely the dominant form, used in primary school spelling lessons, newspapers and academic university texts (which are often American of course).

Now I work in Europe and try to use British spellings when writing in English for my company. But what I have noticed is that only the British use these spellings...non-native speakers of English generally use spellings like 'optimize'. I found this page because I'm now considering just sticking to 'American' spellings - I would have a lot fewer corrections to make in the texts I proofread!

Even if the 'standard' form is -ise in several English-speaking countries, I think that -ize can be considered the global norm.

"I have found both terminations in verbs like optimiz(s)e, prioritiz(s)e, criticis(z)e. Which (or when, or where) is the academically correct form ?"

The answer is yes.

This is not a regional variance issue. Simplifying it as such is obtuse and demonstrates a lack of proper education.

The UK used the -ize form correctly on most words up until World War 2 then started getting lazy and began to use -ise for everything. The Americans did the same, but from the other direction, using the -ize form for words that had always been spelled with an -ise.

This is an excellent article I suggest you read:
http://www.metadyne.co.uk/ize.html

This is a quality discussion. I'm British and lecture on optimization at a major UK university where I have crossed swords occasionally with colleagues and students who insist on change my -ize to -ise. Unfortunately I can't see the preferred usage becoming universal since it would mean asking academics in other groups not to use -ise. UK engineers seem to be the worst when it comes to using -ise, and you can draw your own conclusions regarding their insularity! I appreciate the link in the previous post, too.

As several correspondents have said, the 'ize' spelling is the traditional British form. That is the spelling that our grandparents and grandparents used. The Americans have simply retained that traditional form. Going on about this is simply another boring example of anti-Americanism.

Sorry - grandparents and great-grandparents. Please may we have an 'edit' facility?

The changeover seemed to have happened rather earlier than WW2. These graphs are all for British books:

realise / realize - http://books.google.com/ngrams/graph?content=realise%2Crealize&year_start=1800&year_end=2000&corpus=18&smoothing=3

criticise / criticize - http://books.google.com/ngrams/graph?content=criticise%2Ccriticize&year_start=1800&year_end=2000&corpus=18&smoothing=3&share=

Optimise and prioritise are interesting, as they entered British English well after the change, but the results are different: with optimise the 'ise' version was dominant from the start, but with prioritise it's much less clear cut, perhaps because it's so closely connected with business jargon, which has a heavy American influence:

optimise / optimize - http://books.google.com/ngrams/graph?content=optimise%2Coptimize&year_start=1800&year_end=2000&corpus=18&smoothing=3&share=

prioritise / prioritize - http://books.google.com/ngrams/graph?content=prioritise%2Cprioritize&year_start=1800&year_end=2000&corpus=18&smoothing=3&share=

As a serial 'iser', I can't see what laziness has to do with it, I'm merely using the variation which I was brought up with and which is dominant in the quality press and most publishing in the UK.

@Skeeter Lewis - while I agree there is rather a lot of silly anti-Americanism on some of these pages, I don't really see it here. Writing 'honour' rather then 'honor' doesn't strike me as being anti-Americanism unless I start trying to say it's better. The same with 'ise'. And, don't forget, we have a choice; nobody's forcing anyone to use 'ise'.

@WW - prioritise /proritize is of course a newish verb made from a noun, used predominantly in business, and I think the Z version may be more common here. Other newish businessy verbs made from nouns, like incentivize, also seem to lean towards the Z spelling in BrE.

@WW - I hate to say it, but I misread some of those graphs - in fact optimize with a z was the clear winner from the start. With the older -ise/-ize words, -ise seems to have been dominant between the 1870s and the 1920s, with -ize taking the lead again after that.

I had a look at that Metadyne piece linked to above and have one or two issues with it. My (very) detailed response with lots of examples can be found here:

http://random-idea-english.blogspot.com/2013/01/some-random-thoughts-about-ise-and-ize.html

@Skeeter Lewis - it depends what you call traditional. Until the eighteenth century -ize seems to have dominated, yes. But in the nineteenth century it was the turn of -ise, and writers like Dickens, George Eliot and the Brontes were all first published with -ise verbs. It is -ize that has made a re-appearance, not -ise. And I doubt very much whether my either my parents or grandparents used -ize. Here's David Crystal, who knows more about British English than most people:

"The influence of American textbooks in Britain has caused US spellings to become common in the UK - such as the often encountered -z for -s in such words as atomize, atomizer, atomizable, atomization." (Stories of English p477)

Thank you, Will. Very interesting. It's true I don't remember 'ize' in Dickens.....

Miriam Webster. Realisation, Realism ? hello?? Realise is proper. Don't even get me going on "colour" !!!

@jacksalemi1 - And your point is?

Dear all !
I don't know about 18' th or 19' th Century...all I know is that we are in 21'
st century....communication is must no matter if it is ise or ize....I personally use ize ..It hardly matter if I am interacting with UK client or US..Eg. If I write optimization while communicating with some UK person ...then of course he will know what I mean...and if I write optimisation to my US client he will also know what I am talking about ...as far as spelling check is concerned I think every one know how to change language of laptop or any electronic media .....just change language from UK English to US English and see the difference..

@Mahesh - sure we are in the 21st century, and communication is what language is all about. But language also has a history; we're allowed to be interested in that, aren't we? :)

Incidentally, The Times of India seems surprisingly even-handed in this. A site search brings up:
realise - 41,200, realize - 33,400
recognise - 17,000 recognize - 20,000
optimisation - 2,150, optimization - 5,000
nationalisation - 1,260 nationalization - 1,130

It's an 'S'. It is an English word, that is how the English spell it. American English is simply badly spelt English.