Mathematicians have long recognized the distinction betweenan argument showing that an interesting object exists and aprocedure for actually constructing the object. Computerscience adds a new dimension of interest in constructivity,since a computer program is a formal description of aconstructive procedure that can be executed automatically.It has beenover a decade since a conference was devoted toconstructivity, and never before has one been heldspecifically relating computer science to constructivity.Thus, this proceedings volume is the most concentratedoffering ever produced of the diverse ways in whichconstructivity and computer science are related. The paperscover semantics and type theory, logic and theorem proving,real and complex analysis, topology and combinatorics,nonconstructive graph-theoretical techniques, and curriculumand pedagogic issues.The book offers a concentrated view of the many ways inwhich constructivity has assumed importance in computerscience, and contains results available nowhere else.