Performance evaluation while trying to classify structural classes using functional classes as the features. The low F-measure values indicate that though structure is dependent on function of the protein, the present features are incapable in distinguishing them completely. F-measure was calculated as the harmonic mean between Recall and Precision. Presented table lists classes which showed significant F-measure values. Class-name refers to superfamily in SCOP database. Highly significant F-measure values are shown in bold.