Professor Kravchenko studies low-temperature (millikelvin) properties of low-dimensional electron systems using transport, capacitance, thermopower, and magnetization measurements. His primary interest is to understand the nature of the metal-insulator transition in strongly interacting two-dimensional electron systems, discovered by him and his collaborators. This discovery was the subject of numerous editorial papers in Physics Today, Nature, Science, Science Daily, The Economist, and elsewhere, and was listed on the American Physical Society timeline “A Century of Mesoscopic Physics (1899-1999)” as one of 50 main discoveries of the last century, together with the discovery of the superconductivity, the quantum Hall effect, etc. A broader goal is to study the effects of strong correlations on the properties of the electrons in two dimensions. This is a forefront area of Condensed Matter Physics, where theoretical methods are poorly developed, and experimental results are in great demand. The experiments include studies of Si metal-oxide-semiconductor field-effect transistors, p-SiGe heterostructures, GaAs/AlGaAs heterostructures, and SiGe/Si/SiGe quantum wells at temperatures down to 20 millikelvin and at magnetic fields up to 15 tesla.