Autocorrelation & Independence

These are two very important and intimately related statistical concepts that I’d like to cover so folk can get a better handle on the pitfalls associated with assessment of vaccine benefit/disbenefit. Understand this and you’ll understand a great deal.

The assumption of independence of measure critically underpins all statistical analysis. This is equivalent to assuming the heights of students coming into my classroom are appearing in a random manner as they file through the door. In stats talk we say student height is an independent measure, meaning the height of one student has no bearing whatsoever on the next student coming in to class. I can thus measure heights of the first 10 of 30 students coming in to my morning class and measure the heights of the first 10 of 30 students coming in to my afternoon class and compare them. If my morning class are first year students and my afternoon class final year students then I am going to detect a difference that is meaningful and based on…