A flustered Australian once wrote, “Do you need a new bed mate?” But what he meant to ask was, “Do you need a new bed, mate?” The presence of one little comma can completely change the meaning, and the omission or misplacement of a single punctuation mark can confuse or mislead the reader. In technical documents, such misinterpretations can have serious—even drastic— consequences. This document (Chapter 4 from Technical Style) briefly discusses the mistakes commonly made in technical writing, and it shows you how they should be corrected.
To engineer is to exercise engineering judgment—to make decisions—and it is commonly held that good decisions require good data; but this is a fallacy. Good decisions depend on good analyses, and good analyses can be performed on data that are good or bad. However, a good analysis must begin by assessing the quality of the data we have, for little meaning can be attached to data of unknown quality. This document reviews standard ways for assessing quality; in particular, the emphasis is on distinguishing uncertainties from errors and properly reporting uncertainties.
When a fluid is subjected to an electric field, many properties of the fluid change relative to their values when no field is present; in general, the changes increase with increasing field strength. The purpose of this document is to explain those changes. To keep the discussion simple, we discuss the phenomena within the context of an ideal, parallel-plate capacitor. We focus on the dielectric constant in polar and nonpolar gases and liquids, and we show how the dielectric constant is related to the molecular polarizability, the molecular dipole moment, and the refractive index.