3.8 of Chapter 25, what it means by the referred "factor-based approach"? seems not introduced in any place of the course notes, thanks for advise. and, furthermore, when it comes for the classification for the introduced 6 methods in part 3 of the chapter, may i understand that 3.1, 3.2, 3.3 and 3.6 are statistical methods while 3.4 and 3.5 are case-by-case methods? on that case, as the question above, what's the factor-based approach mean? does it required by the syllabus? concerning there are some analysis regarding the difference of these three method types for certain considerations in the content of 3.8.
3.3 is a factor-based approach - in other words, 'take one answer and multiply it by a factor to get the answer you need'. Yes, your generic classification would be ok, although some people might argue triangulation methods aren't very statistical. Statistical methods generally just mean something involving a distribution assumption somewhere, whereas case-by-case methods look at each, well, case by case.