My experience is that the expectations of "spelling ages" seem quite low - ds9 seems like an awful speller to me, but consistently given a spell age 1-2 yrs ahead of chronological. Of course his writing is so dreadful it can be hard to tell what the spelling is - but that is a different problem ;-)
The Peters Spelling test and the Schonell test are different tests that both provide a 'spelling age' based upon children's ability to spell a series of words. I personally prefer the Peter's test as the words are are bit more
familiar, but just as difficult, to spell. to spell
Peter's and Schonell are not tests that should be done at home regularly as then you are just teaching to the test and that's going to make the school results pointless. It is only done at the beginning and end of a year to see how much they have gained over the year. It's just a guide. They are natural words and sounds you pick up throughout school/home/life.
If you go to the TKI site, you can have a look at information about both the tests you ask about, though not the tests themselves. One is a regular spelling test, as in words called out and children write them down, the other is a test of spelling in context, ie from a passage of text. The link to the TKI site is:
Just one thing about spelling. Sometimes we think kids are not great spellers but they seem to still score quite highly in tests, so then we as parents may assume that the tests are not expecting a high level of achievement.
Another explanation is that often children will spell a word correctly in a spelling test, but may not necessarily do so when they are doing say creative writing. I notice this a lot with my 7 year old daughter, there can be huge discrepancies between her spelling in story writing compared to in a spelling list-I'd assumed she was just a terrible speller,as she writes pretty detailed and imaginative stories but the spelling can be rather random. However, at her parent interview her teacher showed me her spelling list and she spells well above her age level.
Curious as to why you would need it! School will provide spelling words for kids or let them set their own if they are advanced spellers. It's unlikely that anyone can send you a copy of the Peter's Test as it is a diagnostic test used in schools. It is no longer available for purchase.