The Variability of Selected Features in Cursive Handwriting: Categorical Measures

Abstract A scheme for the classification of a selected set of cursively handwritten letters is outlined. It is used to describe the variation of letter forms generated in samples of handwriting taken from 61 right-handed people under controlled conditions. A new measure is presented that summarizes variability within any one individual's handwriting relative to the variability observed between individuals. This measure is termed the Discrimination Index (DI), since it provides an index of the power of a given feature to discriminate between writing samples from different authors. The DI is used to rank the potential usefulness of different features of various letters and letter pairs. The single feature with the overall highest DI was the form taken by the top of letter ascenders ("top of staff") of the six letters studied. The letter k has the highest DI taken over all features. Higher DIs for certain letters were observed when those letters appeared in frequently occurring digrams. A complete tabulation of DIs for all letter/feature combinations examined is provided.