The art of oratory can determine a politician's destiny, but how often do you analyse the language used by one against another?

Here's your chance. The diagram above contrasts David Cameron's speech at the Conservative party conference today with Gordon's Brown's at the Labour conference last week.

The blue bubbles show words used more frequently by Cameron; the red ones are those used more by Brown. The more purple (or central) a word, the more common it was to both leaders' speeches.

The bigger the bubble, the more frequently a word was used; the higher the bubble, the earlier on in the speech. The top of the graph represents the start of each speech, moving through to the end of the speech at the bottom.

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So, Cameron started with the war, moved on to the problems in the financial system and 'broken Britain', and finished with words like 'decade', 'happen' and 'unimaginable' .

The columns on the left and right hand sides represent the length of each speech - so Brown's was marginally longer. The columns also show the course of the speech from start to finish, and are divided into squares which show the speech's sections. The colour of a square shows the extent to which that section used words that were unique to that leader's speech. (A blue square in the Cameron column reflects a section where he used words that Brown did not use; a purple one indicates a section which used words similar to Brown.

The triangles next to each square are an attempt to capture the 'emotional tone' of that section. (Positive words - like 'love' and 'peace' - are represented by upward-pointing green triangles; negative words like 'hate' and 'racism' by downward-pointing red ones.) The stronger the colour in the triangle, the stronger the tone. So, you get a sense - albeit subtle - of how both speeches finished on more positive notes.

The bar at the top shows how much vocabulary was unique to each speech and how much was shared (in purple).

We've also run through the system comparing the then Mrs Thatcher's 1978 speech to conference - the year before she was elected Prime Minister - and Tony Blair's address from 1996, seven months before he entered Number 10. Enjoy the analysis!

(Thanks to Jeff Clark at Neoformix.com for his help.)

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