The article by John Middleton and Jeffrey E. Vaks entitled "Evaluationof Assigned Value Uncertainty for Complex Calibrator Value AssignmentProcesses: A Prealbumin Example" (Clin Chem 2007;53:73541),contains several errors. In the first section of Results, page739, the text should be changed from "The IWC value assignmentresults are shown in Table 1" to "The IWC level 8 results aregiven in Table 1". Also, in Table 2, for IWC5 to IWC8, the decimalpoint in the uncertainty SDs should be shifted one digitto the left. Additionally, in Table 3, footnote b, the referenceinterval should be changed from "... based on width of 20 mg/Lof the... 1838 mg/L" to "... based on width of 200 mg/Lof the ... 180380 mg/L." Also, in Table 3, the superscript"a" should be removed from the 180 and 380 mg/L table entries.Finally, in the 4th paragraph in Results (page 739), the textshould be changed from "... we made 48 measurements (4 instruments,12 replicates per sample) ... to "... we made 96 measurements(4 instruments, 24 replicates per sample) ... ." The authorsregret the errors.