Keyword Extraction from Swedish Court Documents

Sammanfattning: This thesis addresses the problem of extracting keywords which represent the rulings and and grounds for the rulings in Swedish court documents. The problem of identifying the candidate keywords was divided into two steps; first preprocessing the documents and second extracting keywords using a keyword extraction algorithm on the preprocessed documents. The preprocessing methods used in conjunction with the keywords extraction algorithms were that of using stop words and a stemmer. Then, three different approaches for extracting keywords were used; one statistic approach, one machine learning approach and lastly one graph-based approach. The three different approaches used to extract keywords were then evaluated to measure the quality of the keywords and the rejection rate of keywords which were not of a high enough quality. Out of the three approaches implemented and evaluated the results indicated that the graph-based approach showed the most promise. However, the results also showed that neither of the three approaches had a high enough accuracy to be used without human supervision.