ASQ

Exclusive Content & Downloads from ASQ

Problems with Interval Estimation When Data are Adjusted via Calibration

Summary: The analysis of adjusted data arising from a linear calibration curve is considered. Although it is obvious that adjusted values contain errors due to estimation of the calibration curve, some investigators may be tempted to analyze such data as if they are true values of the property of interest. We illustrate some of the problems that arise if one applies "naive" analyses to calibrated data. In particular, it is shown that standard one-sample confidence intervals have actual confidence levels that are always less than the nominal value. We also propose and evaluate two other methods for constructing confidence intervals. Tolerance intervals derived from adjusted data also may yield deceiving results, having actual probability levels that are usually greater than the desired level but smaller in some cases

Anyone with a subscription, including Site and Enterprise members, can access this article.


Other Ways to Access content:

Join ASQ

Join ASQ as a Full member. Enjoy all the ASQ member benefits including access to many online articles.

Subscribe to Journal of Quality Technology

Access this and ALL OTHER Journal of Quality Technology online articles. You'll also receive the print version by mail.

  • Topics:
  • Keywords: Calibration,Confidence intervals,Error,Tolerances
  • Author: Mulrow, Jeri M.; Vecchia, Dominic F.; Buonaccorsi, John P.; Iyer, Hari K.
  • Journal: Journal of Quality Technology