How to Read
the Numbers

The percentage (%) reflects the number of survey respondents who answered yes to a given survey question. All percentages have been rounded up at 0.5 and down at 0.4. Percentages do not necessarily total 100, because of multiple or missing responses.

The mean, or average, is all of the answers added together and then divided by the number of respondents. An average can be influenced by extremely high and extremely low numbers. In some cases, the extremely high and extremely low responses were eliminated to present a more accurate number.

The median is the midpoint, meaning that half of the respondents answered above and half answered below. A median is useful because, unlike an average, it is not influenced by high and low extremes.


In February 2006, three e-mails were sent to IDEA business and program director members who gave IDEA permission to contact them. Respondents linked to a Web-based survey. There were 286 completed questionnaires from the United States and Canada, for a 15% response rate. At a 95% confidence level, the margin of error is ±5%.

  • Percentages in this section are
    likely the respondents’ estimates or observations. Respondents may not have had reference data.

This section of the article is still in the process of conversion to the web.