How do I assess the provenance of a primary source?

This answer specifically applies to OCR A-level History, with reference to the Britain 1900-51 as examples, but can also be used in conjunction with AQA and Edexcel.Provenance of a source is an essential aspect of an source essay and for the top marks should be used in conjunction with the evaluation of the source and 'to what extent' it supports the given view or statement. The key aspects of provenance can simply be remembered as 'who, what, when, where and why;' my advice in an exam would be to quickly jot this on your source handout to ensure it is always something you look out for when annotating your sources.Here's a brief explanation of what to look out for:WHO - Who is the source credited to? Do they hold a position of power or influence (for example, a politician), do they have a particular reputation ascribed to them? A good example here would be in answer to he question 'how far do the four sources support the view that the 1909 budget was a popular measure?' If the source in question was from David Lloyd-George, it would be important to mention 'although this source does support the given view, its scope could be limited due to his nature as the Chancellor of the Exchequer for the Liberal party as he would evidently not oppose the very measures he himself proposed.' (Note this is also adding specific general knowledge, another aspect of the exam criteria.)WHAT - What is the source; a diary, a public speech? What would their intentions have been in using this medium? For example, if the source is a public speech, what is the speaker trying to do, convince someone of something? Warn people of the dangers of something else? Why would the audience affect the way in which a speaker would convey themselves?WHEN - When was the source published, how close was it to the event/ subject being discussed? What else occurred during that time that could have influenced the person's view? For example, Asquith changed his view on women's suffrage over the course of WW1, what changed between this time? Contextually here, you could then mention something such as the loss of his two sons during the war as an explanation; showing that you have paid attention to the date and its surrounding events is always smiled on by the examiners.WHERE- where was the source produced? This could be location-wise, but also pay attention to who published the source. For example, If the source was published in The Times newspaper, it would be good to acknowledge its right-wing stance and evaluate how this would affect its support for the given statement.WHY - Already touched upon under 'what', it is always important to consider why the source is in existence. The perfect example here would be if a source was written in defence of a particular policy or idea; WHY did this policy need defending? If it needs defending then surely it also implies that controversy towards it existed in the first place? This would then be the perfect opportunity to explain how one source both supports and disagrees with the given statement.Any opportunity to cross-reference or contrast sources through mention of their provenance will also help to gain the high marks.