We present methods for the automatic classification of patent applications using an annotated dataset provided by the organizers of the ALTA 2018 shared task - Classifying Patent Applications. The goal of the task is to use computational methods to categorize patent applications according to a coarse-grained taxonomy of eight classes based on the International Patent Classification (IPC). We tested a variety of approaches for this task and the best results, 0.778 micro-averaged F1-Score, were achieved by SVM ensembles using a combination of words and characters as features. Our team, BMZ, was ranked first among 14 teams in the competition.
investigated in depth the hierarchical problem of WIPO-alpha with SVMs @cite_8 @cite_13 @cite_6 . They showed that using a hierarchical approach produced better results. Many studies showed that evaluating a hierarchical classification task is not trivial and many measures can integrate the class ontology. Still, using multiple hierarchical measures can introduce bias @cite_1 . Yet, there was much improvement in the last 3-4 years in the text classification field. This is one reason, why, when reengaging again in the WIPO-alpha dataset, investigating only the top nodes of WIPO class ontology might be a good start for future successive tasks.
@cite_1 @cite_13 @cite_6 @cite_8
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Multi-label Classification (MC) often deals with hierarchically organized class taxonomies. In contrast to Hierarchical Multilabel Classification (HMC), where the class hierarchy is assumed to be known a priori, we are interested in the opposite case where it is unknown and should be extracted from multi-label data automatically. In this case the predictive performance of a classifier can be assessed by well-known Performance Measures (PMs) used in flat MC such as precision and recall. The fact that these PMs treat all class labels as independent labels, in contrast to hierarchically structured taxonomies, is a problem. As an alternative, special hierarchical PMs can be used that utilize hierarchy knowledge and apply this knowledge to the extracted hierarchy. This type of hierarchical PM has only recently been mentioned in literature. The aim of this study is first to verify whether HMC measures do significantly improve quality assessment in this setting. In addition, we seek to find a proper measure that reflects the potential quality of extracted hierarchies in the best possible way. We empirically compare ten hierarchical and four traditional flat PMs in order to investigate relations between them. The performance measurements obtained for predictions of four multi-label classifiers ML-ARAM, ML-kNN, BoosTexter and SVM on four datasets from the text mining domain are analyzed by means of hierarchical clustering and by calculating pairwise statistical consistency and discriminancy. Patent lawsuits are costly and time-consuming. An ability to forecast a patent litigation and time to litigation allows companies to better allocate budget and time in managing their patent portfolios. We develop predictive models for estimating the likelihood of litigation for patents and the expected time to litigation based on both textual and non-textual features. Our work focuses on improving the state-of-the-art by relying on a different set of features and employing more sophisticated algorithms with more realistic data. The rate of patent litigations is very low, which consequently makes the problem difficult. The initial model for predicting the likelihood is further modified to capture a time-to-litigation perspective. Abstract Automatically extracting semantic information about word mean-ing and document topic from text typically involves an extensivenumber of classes. Such classes may represent prede ned wordsenses, topics or document categories and are often organized in ataxonomy. Thelatterencodesimportantinformation,whichshouldbe exploited in learning classi ers from labeled training data. Tothat extent, this paper presents an extension of multiclass SupportVector Machine learning which can incorporate prior knowledgeabout class relationships. The latter can be encoded in the form ofclass attributes, similarities between classes or even a kernel func-tion de ned over the set of classes. The paper also discusses howto specify and optimize meaningful loss functions based on the rel-ative position of classes in the taxonomy. We include experimentalresults for text categorization and for word sense classi cation. 1 Introduction Manyreal-worldclassi cationtasksaremulticlassproblemsinvolvinglargenumbersof classes. This is in particular true for application domains like information re-trieval and natural language processing, where classes may correspond to documentcategories or word senses: several thousand or even tens of thousands of classes arenot uncommon. For instance, the International Patent Classi cation (IPC) scheme[8] consists of approximately 69,000 classes (called groups) that are used to catego-rize patent documents and WordNet 2.0 [3] consists of almost 80,000 word senses(called synsets) de ned by lexicographers to classify the meaning of English nouns.Multiclass problems of this scale pose a severe challenge for learning algorithms andclassi cation accuracies obtained by even the best classi cation methods are oftendisappointingly poor.