Gabriel-Roiter measure (H. Krause) ---------------------- Given a finite dimensional algebra A, the Gabriel-Roiter measure provides a method to study the combinatorial properties of the set of isomorphism classes of indecomposable A-modules. For instance, Roiter used this measure to prove the first Brauer-Thrall conjecture. More recently, Ringel extended this theory, proving for example a refinement of the first Brauer-Thrall conjecture. In my lecture, I will give an elementary introduction into this beautiful theory. A reference is Ringel's survey "Foundation of the Representation Theory of Artin Algebras, Using the Gabriel-Roiter Measure", which is available from his homepage http://www.math.uni-bielefeld.de/~ringel/.