Constitutes the refereed proceedings of the 12th International Conference on String Processing and Information Retrieval, SPIRE 2005, held in Buenos Aires, Argentina in November 2005. These papers address issues in various aspects of string processing, information retrieval, pattern matching, computational biology, and related applications.

String Processing and Information Retrieval 2005.- Enhanced Byte Codes with Restricted Prefix Properties.- Experimental Analysis of a Fast Intersection Algorithm for Sorted Sequences.- Compressed Perfect Embedded Skip Lists for Quick Inverted-Index Lookups.- XML Retrieval with a Natural Language Interface.- Recommending Better Queries from Click-Through Data.- A Bilingual Linking Service for the Web.- Evaluating Hierarchical Clustering of Search Results.- Counting Suffix Arrays and Strings.- Towards Real-Time Suffix Tree Construction.- Rank-Sensitive Data Structures.- Cache-Conscious Collision Resolution in String Hash Tables.- Measuring the Difficulty of Distance-Based Indexing.- N-Gram Similarity and Distance.- Using the k-Nearest Neighbor Graph for Proximity Searching in Metric Spaces.- Classifying Sentences Using Induced Structure.- Counting Lumps in Word Space: Density as a Measure of Corpus Homogeneity.- Multi-label Text Categorization Using K-Nearest Neighbor Approach with M-Similarity.- Lydia: A System for Large-Scale News Analysis.- Composite Pattern Discovery for PCR Application.- Lossless Filter for Finding Long Multiple Approximate Repetitions Using a New Data Structure, the Bi-factor Array.- Linear Time Algorithm for the Generalised Longest Common Repeat Problem.- Application of Clustering Technique in Multiple Sequence Alignment.- Stemming Arabic Conjunctions and Prepositions.- XML Multimedia Retrieval.- Retrieval Status Values in Information Retrieval Evaluation.- A Generalization of the Method for Evaluation of Stemming Algorithms Based on Error Counting.- Necklace Swap Problem for Rhythmic Similarity Measures.- Faster Generation of Super Condensed Neighbourhoods Using Finite Automata.- Restricted Transposition Invariant Approximate String Matching UnderEdit Distance.- Fast Plagiarism Detection System.- A Model for Information Retrieval Based on Possibilistic Networks.- Comparison of Representations of Multiple Evidence Using a Functional Framework for IR.- Deriving TF-IDF as a Fisher Kernel.- Utilizing Dynamically Updated Estimates in Solving the Longest Common Subsequence Problem.- Computing Similarity of Run-Length Encoded Strings with Affine Gap Penalty.- L 1 Pattern Matching Lower Bound.- Approximate Matching in the L ??? Metric.- An Edit Distance Between RNA Stem-Loops.- A Multiple Graph Layers Model with Application to RNA Secondary Structures Comparison.- Normalized Similarity of RNA Sequences.- A Fast Algorithmic Technique for Comparing Large Phylogenetic Trees.- Practical and Optimal String Matching.- A Bit-Parallel Tree Matching Algorithm for Patterns with Horizontal VLDC’s.- A Partition-Based Efficient Algorithm for Large Scale Multiple-Strings Matching.