\contentsline {chapter}{\numberline {1}Introduction}{1} \contentsline {section}{\numberline {1.1}Statement of Thesis}{4} \contentsline {section}{\numberline {1.2}Contributions of this Thesis}{4} \contentsline {section}{\numberline {1.3}Structure of this Thesis}{4} \contentsline {chapter}{\numberline {2}Background and Related Work}{5} \contentsline {section}{\numberline {2.1}Prototype Learning for Nearest Neighbor Classifiers}{6} \contentsline {subsection}{\numberline {2.1.1}Instance Selection}{6} \contentsline {subsubsection}{Condensed Nearest Neighbor (CNN)}{6} \contentsline {subsubsection}{Reduced Nearest Neighbor (RNN)}{8} \contentsline {subsubsection}{Minimal Consistent Set (MCS)}{8} \contentsline {subsection}{\numberline {2.1.2}Instance Abstraction}{9} \contentsline {subsubsection}{Chang}{9} \contentsline {section}{\numberline {2.2}Evaluation of Prototype Learning Schemes}{10} \contentsline {subsection}{\numberline {2.2.1}Storage Reduction}{10} \contentsline {subsection}{\numberline {2.2.2}Speed Increase}{10} \contentsline {subsection}{\numberline {2.2.3}Generalization Accuracy}{10} \contentsline {subsection}{\numberline {2.2.4}Noise Tolerance}{10} \contentsline {subsection}{\numberline {2.2.5}Probability of Detection and False Alarm}{10} \contentsline {chapter}{\numberline {3}CLIFF: Tool for Instance Selection}{12} \contentsline {section}{\numberline {3.1}CLIFF}{13} \contentsline {section}{\numberline {3.2}CLIFF: A Simple Example}{15} \contentsline {section}{\numberline {3.3}CLIFF: Time Complexity}{16} \contentsline {chapter}{\numberline {4}CLIFF Assessment}{17} \contentsline {section}{\numberline {4.1}Data and Preprocessing Tools}{17} \contentsline {subsection}{\numberline {4.1.1}Data Set Characteristics}{17} \contentsline {subsection}{\numberline {4.1.2}Pre-processing tools for Dimensionality Reduction}{18} \contentsline {subsubsection}{FastMap}{18} \contentsline {subsubsection}{Feature Subset Selection (FSS)}{19} \contentsline {section}{\numberline {4.2}CLIFF Assessment on Standard Data Sets}{22} \contentsline {subsection}{\numberline {4.2.1}Data}{22} \contentsline {subsection}{\numberline {4.2.2}Experimental Method}{22} \contentsline {subsection}{\numberline {4.2.3}Experiment ####1: Is CLIFF viable as a Prototype Learning Scheme for NNC?}{23} \contentsline {subsection}{\numberline {4.2.4}Experiment ####2: How well does CLIFF handle the presence of noise?}{23} \contentsline {chapter}{\numberline {5}Case Study: Solving the Problem of Brittleness in Forensic Models}{31} \contentsline {section}{\numberline {5.1}Introduction}{31} \contentsline {section}{\numberline {5.2}Visualization of Brittleness}{33} \contentsline {section}{\numberline {5.3}Glass Forensic Models}{33} \contentsline {subsection}{\numberline {5.3.1}Seheult 1978}{34} \contentsline {subsection}{\numberline {5.3.2}Grove 1980}{35} \contentsline {subsection}{\numberline {5.3.3}Evett 1995}{36} \contentsline {subsection}{\numberline {5.3.4}Walsh 1996}{37} \contentsline {section}{\numberline {5.4}Visualization of Brittleness in Models}{38} \contentsline {section}{\numberline {5.5}Introduction}{40} \contentsline {section}{\numberline {5.6}Dimensionality Reduction}{42} \contentsline {subsection}{\numberline {5.6.1}Principal Component Analysis}{42} \contentsline {section}{\numberline {5.7}Clustering}{45} \contentsline {section}{\numberline {5.8}Classification with KNN}{45} \contentsline {section}{\numberline {5.9}The Brittleness Measure}{47} \contentsline {section}{\numberline {5.10}Data Set and Experimental Method}{48} \contentsline {section}{\numberline {5.11}Experiment 1: KNN as a forensic model?}{49} \contentsline {subsection}{\numberline {5.11.1}Results from Experiment 1}{49} \contentsline {section}{\numberline {5.12}Experiment 2: Can brittleness be reduced?}{50} \contentsline {subsection}{\numberline {5.12.1}Results from Experiment 2}{52} \contentsline {chapter}{\numberline {6}Conclusion}{56}