Man you were so hard, I think he meant the functions behind the algorithms responded to O(log2(n)) asymptotic performance. The big o notation has many uses in other fields but in computing is used with its basic meaning, that's to remark the asymptotic character of the expression enclosed for the function being referred.
Man it seemed you were dying to get the book out of the shelf and spit out some theoretical speech. I think you got the point first time, didn't you?
Peace