Hi: Are you perhaps thinking of conjoint analysis?
Dennis On Wed, Jan 5, 2011 at 1:30 AM, Graham Smith <myotis...@gmail.com> wrote: > Ben > > > > Perhaps you can specify your question more precisely, or differently. > > The way I interpret it, if there are no interactions in price > > (e.g. you get a discount for buying more than one book at a time) > > or in value (e.g. you learn more from one book having read another), > > then you get the best value/price ratio by taking only the book with > > the highest value/price. (If you take no books at all, your value/price > > ratio is undefined.) The algebra below shows that combining a lower > > value/price book with a higher one always lowers your overall value/price > > ratio. > > > > Thanks, for the pointers on R functions. My question was as superficial as > it sounded. I have a commercial programme that does this (one of several > that are available), and wondered if there was an R package that provided > the same tools. It's a common tool, and I had hoped to have explained > enough > to allow an appropriate package to be identified, so I could have a quick > look at what it does. > > But having started this, I now feel obliged to clarify the question. I only > chose books as an easy example, you could substitute alternative marketing > strategies, monitoring programmes, choice of ornaments for a new house, or > holidays etc. So there could be only a few potential combinations or > hundreds. > > But to stick with the books, and only three options: A, B and C > > Book A costs $100 and I have given it a subjective value of 50 > Book B costs $36 and I have given it a subjective value of 60 > Book C costs $50 and I have given it a subjective value of 80 > > So book A is costing me $2 per value unit, Book B $0.6 per value unit and > book C £0.63 per value unit. > > Buying books A+B gives me a $1.24 per value unit > Buying books A+C gives $1.07 per value unit > Buying books B+C gives 0.61 per value unit > Buying books A+B+C gives 0.97 per value unit > > So in terms of value for money, there are three contenders > > Book B on its own, Book C on its own, or buying both books B and C. > > Book B $36.00 and value 60 > Book C $50.00 and value 80 > Book B+C at $76.00 and value 140 > > Depending on how you are using this tool, you can either use it to decide > how spend an existing budget, or use it to set a budget. > > Seems hardly worth the bother for three books but if you are looking at 20 > books or 30 different monitoring options etc, it gives a useful insight > into > how best to spend or set a budget > > The commercial software graphs this costs vs values so you usually end up > with some sort of an asymptotic graph where you can see that spending below > a certain budget gives a very poor return. > > Graham > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
