independent the results of an observation are i. of another obeservation when the outcome of the one observation makes no difference to the outcome of the other, e.g., observing blue-eyed people does not effect the observance of tall people; independence guides the techniques for combining probabilities, cf. depend, Carol Ash (1993), pp. 37-45); probability calculations follow the principle of i. probabilities; cf. Ch. 2, §2, ¶5 & Chapter 5, §3, ¶1