9. A method for triggering a sub-word unit recognition comprising: drawing one or more strokes of a desired sub-word unit using a stylus on a touch screen, wherein one of the drawn one or more strokes is a first head-line stroke and is a last drawn stroke in the drawn one or more strokes of the desired sub-word unit; inputting an associated data of the drawn one or more strokes via the touch screen into a handwriting recognition engine; computing stroke recognition characteristics of each of the drawn one or more strokes with reference to a horizontal reference line, wherein the stroke recognition characteristics are selected from the group comprising aspect ratio and slope; determining a first trigger stroke in the drawn one or more strokes of the desired sub-word unit that can be used to trigger the sub-word unit recognition based as a function of the computed stroke recognition characteristics of each of the multiple drawn strokes, wherein the first trigger stroke is the first head-line stroke which is drawn substantially parallel to the horizontal reference line; and triggering sub-word unit recognition for the drawn one or more strokes by the handwriting recognition engine upon determining the first trigger stroke.
9. A method for triggering a sub-word unit recognition comprising: drawing one or more strokes of a desired sub-word unit using a stylus on a touch screen, wherein one of the drawn one or more strokes is a first head-line stroke and is a last drawn stroke in the drawn one or more strokes of the desired sub-word unit; inputting an associated data of the drawn one or more strokes via the touch screen into a handwriting recognition engine; computing stroke recognition characteristics of each of the drawn one or more strokes with reference to a horizontal reference line, wherein the stroke recognition characteristics are selected from the group comprising aspect ratio and slope; determining a first trigger stroke in the drawn one or more strokes of the desired sub-word unit that can be used to trigger the sub-word unit recognition based as a function of the computed stroke recognition characteristics of each of the multiple drawn strokes, wherein the first trigger stroke is the first head-line stroke which is drawn substantially parallel to the horizontal reference line; and triggering sub-word unit recognition for the drawn one or more strokes by the handwriting recognition engine upon determining the first trigger stroke. 18. The method of claim 9 , wherein, in determining the first trigger stroke and the second trigger stroke, the first trigger stroke and the second trigger stroke are associated with drawing a punctuation mark, head line of the sub-word unit, a repetitive stroke of the sub word unit, and reliably recognizable stroke of the sub-word unit.