The CQI is a composite score of the ratings that were found for each winery for the seven major varietal categories: Sauvignon Blanc, Chardonnay, Pinot Noir, Riesling, Merlot, Cabernet Sauvignon, and Aromatic Whites. Seven major sources, books and periodicals, were used for the 2004 revision. Some sources rate the wineries and some rate the wines. Some use a 1 to 5 rating and some use a 100 point scale. All the available information was digested to give you a composite score on the 1 to 5 scale. There were over 5000 reviews from the seven sources which were categorized into approximately 3200 review units; which is one source for one winery for one varietal. Note that some sources may review more than half a dozen different label designations from a single winery for a specific varietal which were averaged for that review unit.
While the results are generally in line with conventional wisdom, there may be some raised eyebrows (mine included) about some of the results. In some cases where a top brand is not on the list, a notable producer may have a range of wines with different label designations i.e. Reserve, single vineyard, etc. While the average or lower range wines can lower the overall rating for the winery, the Reserve wine may be extraordinary, a point the consumer should keep in mind while reading and shopping.
Another factor affecting the composite rating is the variance between the reviewers and the "reputation" factor. Different review sources can be more conservative or more generous in their scoring. Established wineries with solid reputations tend to maintain their scores while new wineries may be disadvantaged by their lack of reputation. Conversely, the well-known wineries are more often reviewed by sources that are conservative, lowering their average, while the newer winery can benefit from having a limited number of reviews from generous sources.
Future revisions of the CQI will look to incorporate other sources such as competition results (which would also add a new set of footnotes and caveats). In the meantime, everyone is encouraged to try New Zealand wine and form his or her own opinions.