Jerome Workman Jr. serves on the Editorial Advisory Board of Spectroscopy and is currently with Unity Scientific LLC. He is also an adjunct professor at Liberty University and U.S. National University. He can be reached at jworkman04@gsb.columbia.edu.

Statistics and Chemometrics for Clinical Data Reporting, Part II: Using Excel for Computations

October 1st 2009In this installment, columnists Jerome Workman and Howard Mark describe the statistical underpinnings related to computation and interpretation of chemometric methods and statistics for reporting clinical quantitative measurement methods.

Statistics and Chemometrics for Clinical Data Reporting, Part I

June 1st 2009This article describes the application of chemometric methods and statistics for reporting clinical quantitative measurement methods. The equations and terminology are consistent with the Clinical and Laboratory Standards Institute (CLSI) guidelines. These chemometric and statistical methods describe the accuracy and precision of a test method compared to a reference method for a single analyte determination. Part I will introduce these concepts and Part II will discuss the statistical underpinnings in greater detail.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part VI

February 1st 2009This column is a continuation of the set we have been working on to explain and derive the equations behind principal components (1–5). As we usually do, when we continue the discussion of a topic through more than one column, we continue the numbering of equations from where we left off.

Addendum to Chemometrics in Spectroscopy

June 1st 2007This column is the continuation of a series (1-5) dealing with the rigorous derivation of the expressions relating the effect of instrument (and other) noise to its effects on the spectra we observe. Our first column in this series was an overview. While subsequent columns dealt with other types of noise sources, the ones listed analyzed the effect of noise on spectra when the noise is constant detector noise (that is, noise that is independent of the strength of the optical signal). Inasmuch as we are dealing with a continuous series of columns, on this branch in the thread of the discussion, we again continue the equation numbering and use of symbols as though there were no break. The immediately previous column (5) was the first part of this set of updates of the original columns.

Linearity in Calibration: Quantifying Nonlinearity, Part II

January 1st 2006At this point in our series dealing with linearity, we have determined that the data under investigation do indeed show a statistically significant amount of nonlinearity, and we have developed a way of characterizing that nonlinearity. Our task now is to come up with a way to quantify the amount of nonlinearity, independent of the scale of either variable, and even independent of the data itself.

Chemometrics in Spectroscopy ? Linearity in Calibration: Quantifying Nonlinearity, Part II (PDF)

January 1st 2006At this point in our series dealing with linearity, we have determined that the data under investigation do indeed show a statistically significant amount of nonlinearity, and we have developed a way of characterizing that nonlinearity. Our task now is to come up with a way to quantify the amount of nonlinearity, independent of the scale of either variable, and even independent of the data itself.

Published: April 29th 2024 | Updated: May 10th 2024

William F. Meggers: The Dean of American Spectroscopists

Published: September 10th 2024 | Updated: September 17th 2024

MRR: A New Tool in Applied Analysis for the Pharmaceutical Industry

Published: September 11th 2024 | Updated: September 17th 2024

In-Service Samples: An Infrared Differential Spectra Issue

Published: September 4th 2024 | Updated: September 17th 2024

Rapid Quantitative Method in the Determination of Total Flavonoids in Tibetan Medicine Meconopsis integrifolia (Maxim.) Franch. from Qinghai-Tibet Plateau by Near Infrared Spectroscopy

Published: September 5th 2024 | Updated: September 17th 2024

Advances in Infrared Spectroscopy for Today’s Spectroscopists

Published: September 3rd 2024 | Updated: September 17th 2024

Lithium-Ion Battery Analysis: A Virtual Symposium