Derived market estimates use available secondary research combined with original research from a Wikibon contributor to create a market estimate that is deemed by the community to be credible and defensible. A Wikibon contributor will use secondary research, primary research, statistical analysis, financial analysis and modeling to derive estimates for market sizes.
Top Down / Bottom Up
Frequently, Wikibon contributors will use a so-called "Top Down / Bottom Up" methodology to derive estimates. Top down refers to a technique of estimating a market size using a global figure, for example the size of the entire IT business, to estimate a sub-market, for example, storage spending. Surveys of corporations, for example, might suggest that on average, companies spend 50% of hardware budgets on storage. This figure is applied in a "Top Down" manner to a global figure from secondary market sources, for example the size of the hardware market in a given year, to derive an estimate for storage spending in a given time period.
Bottom up refers to a methodology that would use a units X average price = total spend approach. For example, secondary sources might indicate how many units were shipped in a given year. Primary research can uncover the average price per unit and total spending can be derived.
It is common for contributors to use both methods in deriving market estimates and comparing these with secondary sources. Contributors will also account for differences in methodologies in the various secondary sources (e.g. global factors, OEM vs. end user spending, street vs. list prices, etc).