The book provides an overview of the author's work devoted to experimental study of hopping conductivity, which includes substantial contributions, such as solving the problem of critical indices of the metal-insulator transition in doped semiconductors, investigation of transitions from different kinds of hopping conductivity, development of the "e;hopping spectroscopy"e; method that allows to reveal the details of the density-of-states near the Fermi level — appearance of a hard "e;magnetic gap"e;, temperature induced smearing of the soft Coulomb gap, the "e;phononless"e; hopping and so on. A separate chapter is devoted to the hopping photoconductivity and inter-impurity radiative recombination of non-equilibrium carriers. This book is suitable for undergraduate and graduate students in physics, researchers in semiconductor electronics and even for the non-experts who wish to have a notion about hopping mechanism of transport. The explanations in the book are simple and detailed enough to capture the interest of the curious reader.Contents:Critical Indices of the Metal-Insulator TransitionDifferent Types of Hopping Conductivity"e;Hopping Spectroscopy"e;Spin-Dependent and "e;Phononless"e; Hopping Conductivity1/f NoiseApplication of the Hopping ConductionInter-Impurity Radiative Recombination and Hopping PhotoconductivityReadership: This book is suitable for undergraduate and graduate students in physics, researchers in semiconductor electronics and even for the non-experts who wish to have a notion about hopping transport.Key Features:The phenomena described and discussed in this book (with few exceptions) are not covered in the existing textbooks and reviewsA new method of "e;hopping spectroscopy"e;, which allows to reveal the details of the density-of-states near the Fermi level, is developedThis book is suitable for undergraduate and graduate students in physics, researchers in semiconductor electronics and even for the non-experts who wish to have a notion about hopping transport.