This book constitutes the joint refereed proceedings of the 6th International Workshop on Approximation Algorithms for Optimization Problems, APPROX 2003 and of the 7th International Workshop on Randomization and Approximation Techniques in Computer Science, RANDOM 2003, held in Princeton, NY, USA in August 2003.

Contributed Talks of APPROX.- Correlation Clustering with Partial Information.- Improved Linear Time Approximation Algorithms for Weighted Matchings.- Covering Graphs Using Trees and Stars.- An Improved Decomposition Theorem for Graphs Excluding a Fixed Minor.- Approximation Algorithms for Channel Allocation Problems in Broadcast Networks.- Asymmetry in k-Center Variants.- An FPTAS for Quickest Multicommodity Flows with Inflow-Dependent Transit Times.- On the Complexity of Approximating k-Dimensional Matching.- Approximating Market Equilibria.- Approximating the Degree-Bounded Minimum Diameter Spanning Tree Problem.- On the Hardness of Approximate Multivariate Integration.- A 2-Approximation Algorithm for the Soft-Capacitated Facility Location Problem.- Approximating Rooted Connectivity Augmentation Problems.- Effective Routing and Scheduling in Adversarial Queueing Networks.- Approximation Schemes for Generalized 2-Dimensional Vector Packing with Application to Data Placement.- An Improved Algorithm for Approximating the Radii of Point Sets.- Contributed Talks of RANDOM.- Testing Low-Degree Polynomials over GF(2).- Computational Analogues of Entropy.- Bounds on 2-Query Codeword Testing.- The Lovász Number of Random Graphs.- Perfectly Balanced Allocation.- On Extracting Private Randomness over a Public Channel.- High Degree Vertices and Eigenvalues in the Preferential Attachment Graph.- The Satisfiability Threshold for Randomly Generated Binary Constraint Satisfaction Problems.- Continuous-Time Quantum Walks on the Symmetric Group.- Distribution-Free Property Testing.- On the Graph-Density of Random 0/1-Polytopes.- A Gambling Game Arising in the Analysis of Adaptive Randomized Rounding.- Tight Bounds for Testing Bipartiteness in General Graphs.- Discrete Quantum WalksHit Exponentially Faster.- Approximate Testing of Visual Properties.- Faster Algorithms for MAX CUT and MAX CSP, with Polynomial Expected Time for Sparse Instances.- A Nearly Linear Size 4-Min-Wise Independent Permutation Family by Finite Geometries.