The article by Kim, Gibbs, Tang, Wang, and Snyder discusses the characterization of the Lorenz number using Seebeck coefficient measurements. The authors propose an equation, \( L = 1.5 + \exp[-\frac{S}{16}] \), to estimate the Lorenz number \( L \) based on the measured thermopower \( |S| \). This equation is derived from the single parabolic band (SPB) model with acoustic phonon scattering and is accurate within 5% for single parabolic band materials and within 20% for more complex materials like PbSe, PbS, PbTe, and Si$_{0.8}$Ge$_{0.2}$. The proposed equation simplifies the estimation of \( L \) without requiring numerical solutions, which is crucial for improving the accuracy of lattice thermal conductivity estimates in thermoelectric materials. The study highlights the importance of careful evaluation of \( L \) to avoid misleading results, especially in materials with non-degenerate semiconductors where \( L \) deviates significantly from the degenerate limit.The article by Kim, Gibbs, Tang, Wang, and Snyder discusses the characterization of the Lorenz number using Seebeck coefficient measurements. The authors propose an equation, \( L = 1.5 + \exp[-\frac{S}{16}] \), to estimate the Lorenz number \( L \) based on the measured thermopower \( |S| \). This equation is derived from the single parabolic band (SPB) model with acoustic phonon scattering and is accurate within 5% for single parabolic band materials and within 20% for more complex materials like PbSe, PbS, PbTe, and Si$_{0.8}$Ge$_{0.2}$. The proposed equation simplifies the estimation of \( L \) without requiring numerical solutions, which is crucial for improving the accuracy of lattice thermal conductivity estimates in thermoelectric materials. The study highlights the importance of careful evaluation of \( L \) to avoid misleading results, especially in materials with non-degenerate semiconductors where \( L \) deviates significantly from the degenerate limit.