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We regularly survey area CHECKBOOK and Consumer Reports subscribers for their feedback on services they have used. For our survey on window washing services, we asked consumers to rate their experiences with firms they had most recently used "inferior," "adequate," or "superior" on several aspects of service, including "doing service properly on the first try," "starting and completing service promptly," "letting you know cost early," "neatness of work," and "overall performance." Our ratings tables show the percent of each firm's surveyed customers who rated it "superior" (as opposed to "inferior" or "adequate") on each question. Our ratings tables show the percent of each firm's surveyed customers who rated it "adequate" or "superior" (as opposed to "inferior") for "overall performance."
We have included in our ratings tables all of the firms for which we received at least 10 ratings on our customer surveys. If a firm is not listed in our ratings tables, it simply means we did not receive at least 10 ratings for it; that fact has no negative or positive implications.
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.
Information reported in our ratings tables regarding areas served came directly from the firms' representatives. We mailed a survey to each firm. If a firm did not respond to our mailed survey, we called it and completed the survey over the phone, then followed up with a mailed verification form.
To compare prices, our shoppers made a number of calls to each of the firms included in our last full, published report and, without revealing their affiliation with CHECKBOOK, obtained prices for three hypothetical window washing jobs.
To compute our price index scores, we calculated an average price for each job or item for all the firms that quoted on that job or item. Next we compared each firm's price to the average. One firm might come in at 120 percent of the multi-firm average for a particular job, and another firm might come in at 90 percent. We took each firm's percentage score on each job or item, standardized it, and assigned a weight to each job or item, based on our judgment. We then averaged the standardized, weighted percentage scores to find how the firm compared to other firms overall. Finally, we multiplied this overall percentage score by a flat dollar amount, say, $100.
The price index score, then, is intended to indicate the relative prices we found for the firms, adjusted to the base of this flat dollar amount. These index scores are imperfect for various reasons: for instance, the jobs or items checked may not be representative; the weighting of various jobs or items in the index may not accurately reflect typical expenditure patterns; and the number of jobs or items is small.
All of the data must be interpreted in view of timeliness. Our customer survey data are from surveys conducted from September 2003 to April 2011. Survey respondents were asked to report on experiences in the preceding year. The data from our survey of firms were collected from September to November 2008. Our price data were collected from May to September 2008.
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.
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