Systematic errors are unfortunately common in analyses performed by students in teaching laboratories. Quality control (QC) tools are required to detect and solve bias in laboratory analyses. However, although QC has become routine in real-world laboratories, it is still rarely applied in teaching laboratories. For this reason, systematic errors…

The method of least-squares (LS) has a built-in procedure for estimating the standard errors (SEs) of the adjustable parameters in the fit model: They are the square roots of the diagonal elements of the covariance matrix. This means that one can use least-squares to obtain numerical values of propagated errors by defining the target quantities as…

Complex error propagation is reduced to formula and data entry into a Mathcad worksheet or an Excel spreadsheet. The Mathcad routine uses both symbolic calculus analysis and Monte Carlo methods to propagate errors in a formula of up to four variables. Graphical output is used to clarify the contributions to the final error of each of the…

The cross-proportion method allows both the instructor and the student to easily determine where an error is made during problem solving. The C-P method supports a strong cognitive foundation upon which students can develop other diagnostic methods as they advance in chemistry and scientific careers.