Page 29 - Preparing equipment for the tests - of the KS2 ARA refers to dictionaries. Remember that it has to be "normal classroom practice" - i.e. your pupils would use a dictionary in any other writing test/individual task. You must also be able to prove it if the moderators drop in for a visit. At my school we don't usually allow dictionaries in any of the papers, even where allowed, unless specified on an IEP, in which case we can prove that it is normal classroom practice. If you're still not sure, your LA's assessment team should be able to help you, or the helpline (number at the back of the ARA) are usually quite helpful too. Hope that's helpful.