The word knowledge is defined first as the “acquaintance with facts, truths or principles, as from study or investigation; general scholarship.” We must equate knowledge with firmly held true belief. Asking just how firm that belief must be is akin to asking just how big something has to be to count as being big. There is no answer to the question because ‘big’ lacks the sort of boundary enjoyed by precise words. To that extent, ‘know’ is vague. If knowledge entails certainty, then too little will count as known.
For scientific purposes, the best we can do is to give up the notion of knowledge and make do rather with its separate ingredients. We can still speak of a belief as true, and of one belief as firmer or more certain, to the believer’s mind, than another.
Analytics provide assertion for the beliefs expressed by the analysts. Analysts have trouble telling us, ‘there is no knowledge.’ Beliefs asserted by the big-data analysts are taken as sufficient for the analysed states of buying, consuming, or behaving. However, assertion does indeed require the analysts to attribute knowledge to themselves.