Our tables rating individual firms will be more valuable to you if you know how the data were gathered and how they should be interpreted.

Opinion Surveys

Customer survey scores reported on our tables are from our surveys of Consumer Reports and CHECKBOOK subscribers, conducted via mail and the Internet.

Since many firms were rated by rather small numbers of raters, small differences between two firms in the percentage of raters who gave a particular rating (say, "superior") should be ignored. The table below gives a rough guide to minimum differences you should look for in deciding on one firm over another.

When using these survey data, remember that the questions are to some degree subjective and that the differences among firms might be explained by differences in the personalities, backgrounds, critical standards, and other characteristics of the raters or by biases these raters might have.

Survey of Firms

To gather much of the other information on our tables, we surveyed the firms. In general, our researchers surveyed firms by phone (sometimes without revealing their affiliation with CHECKBOOK), but in some cases data were collected by mail or from firms' websites, or phone responses were confirmed by mail follow-up.

Timeliness of the Data

All of the data must be interpreted in view of timeliness. Our customer survey data are from surveys conducted from April 2002 to June 2008. Survey respondents were asked to report on experiences in the preceding year or, in some cases, two years or three years. Our survey of physicians was conducted from April to September 2001. The data from our survey of firms were collected from December 2003 to February 2004.

For the most part, our tables include firms for which we collected 10 or more ratings on our customer survey during the customer survey period mentioned above, but we do not report data for periods prior to firms' changes of name and ownership. As a result, some large firms are not listed at all. If only name or ownership changed, we do report the data. Changes subsequent to the dates listed above may not be taken into account.

Top Ratings

We give checkmarks to firms that score highest on a scoring system that we devise for each service field. Our scoring systems weight the various data in our tables and text based on our subjective judgment of their importance. Since the scores are based entirely on information presented, you can apply your own subjective judgments, and decide whether you prefer firms we have not given checkmarks. Where we do not have important data on a firm, we cannot give our checkmark.