Integer quantum Hall effect and related phenomena

Experimental and theoretical research on the integer quantum Hall effect is reviewed, together with other transport phenomena in a two-dimensional electron gas in a quantizing magnetic field. Particular emphasis is placed on primary experimental data, on the comparison of experimental and theoretical results, and on the analysis of theoretical predictions from the point of view of their experimental verification. Among experiments conducted in recent years, those that have raised questions to be resolved are highlighted. Possible directions of further research are suggested.