Algorithms on Trees -- Range Quantile Queries: Another Virtue of Wavelet Trees -- Constant Factor Approximation of Edit Distance of Bounded Height Unordered Trees -- k2-Trees for Compact Web Graph Representation -- On-Line Construction of Parameterized Suffix Trees -- Compressed Indexes -- Succinct Text Indexing with Wildcards -- A Compressed Enhanced Suffix Array Supporting Fast String Matching -- Compressed Suffix Arrays for Massive Data -- On Entropy-Compressed Text Indexing in External Memory -- Compression -- A Linear-Time Burrows-Wheeler Transform Using Induced Sorting -- Novel and Generalized Sort-Based Transform for Lossless Data Compression -- A Two-Level Structure for Compressing Aligned Bitexts -- Directly Addressable Variable-Length Codes -- Content Analysis -- Identifying the Intent of a User Query Using Support Vector Machines -- Syntactic Query Models for Restatement Retrieval -- Use of Co-occurrences for Temporal Expressions Annotation -- On-Demand Associative Cross-Language Information Retrieval -- A Comparison of Data-Driven Automatic Syllabification Methods -- Indexing -- Efficient Index for Retrieving Top-k Most Frequent Documents -- Fast Single-Pass Construction of a Half-Inverted Index -- Two-Dimensional Distributed Inverted Files -- Indexing Variable Length Substrings for Exact and Approximate Matching -- String Algorithms and Bioinformatics -- Expectation of Strings with Mismatches under Markov Chain Distribution -- Consensus Optimizing Both Distance Sum and Radius -- Faster Algorithms for Sampling and Counting Biological Sequences -- String Algorithms and Theory I -- Towards a Theory of Patches -- The Frequent Items Problem, under Polynomial Decay, in the Streaming Model -- Improved Approximation Results on the Shortest Common Supersequence Problem -- String Algorithms andTheory II -- Set Intersection and Sequence Matching -- Generalised Matching -- Practical Algorithms for the Longest Common Extension Problem -- Using and Understanding Usage -- A Last-Resort Semantic Cache for Web Queries -- A Task-Based Evaluation of an Aggregated Search Interface -- Efficient Language-Independent Retrieval of Printed Documents without OCR -- Sketching Algorithms for Approximating Rank Correlations in Collaborative Filtering Systems.

This book constitutes the refereed proceedings of the 16th String Processing and Information Retrieval Symposium, SPIRE 2009 held in Saariselkä, Finland in August 2009. The 34 revised full papers were carefully reviewed and selected from 84 submissions. The papers are organized in topical sections on algorithms on trees, compressed indexes, compression, indexing, content analysis, string algorithms and bioinformatics, string algorithms and theory, and using and understanding usage.