Computing Science is a science of constructive methods. The solution of a problem has to be described formally by constructive techniques, if it is to be evaluated on a computer. The Marktoberdorf Advanced Study Institute 1988 presented a comprehensive survey of the recent research in constructive methods in Computing Science. Some approaches to a methodological framework and to supporting tools for specification, development and verification of software systems were discussed in detail. Other lectures dealt with the relevance of the foundations of logic for questions of program construction and with new programming paradigms and formalisms which have proven to be useful for a constructive approach to software development. The construction, specification, design and verification especially of distributed and communicating systems was discussed in a number of complementary lectures. Examples for those approaches were given on several levels such as semaphores, nondeterministic state transition systems with fairness assumptions, decomposition of specifications for concurrent systems in liveness and safety properties and functional specifications of distributed systems. Construction methods in programming that were presented range from type theory, the theory of evidence, theorem provers for proving properties of functional programs to category theory as an abstract and general concept for the description of programming paradigms.