Confused in "analogous estimating" method
I'm confused in the "Analogous estimating" method
in PMBOK 4th version, page 171 states that "analogous estimating uses the value of parameters, such as scope, cost, budget, and duration or measures of scale such as size, weight, and complexity, from a previous, similar project as the basis for estimating the same parameter or measure for a current project."
1. From the definition, it's very much we need to use the actual historical data for it. However, in Rita's book 6th edition, question 5, page 250, the choice "Analogous estimating use historical data" is not a correct choice.
2. in my experience, I usually use Analogous estimating as bottom-up approach, but not sure why it seems PMBOK promote this method as "top-down", which I feel quite unconfortable and don't know how what to call the estimating way that I'm doing so far (as I also try to use the same term that PMI promote)
Any advise on this?