Ruling. Thompson acknowledges the four manuscript share an orderly layout and similar graphic style, creating the appearance of uniformity. Yet she warns that each manuscript page is a "complex object built up from different layers of scribal features applied in a given sequence. Each item (e.g. margins, rulings, scripts, corrections, annotations) when detached from the written web, provides evidence about the genesis of the manuscripts, and throws light on the chronology of scribal activity." She warns against studying only one of these characteristics and drawing conclusions based on information in isolation. Clearly having done the work as part of her dissertation, she chose to focus on staff ruling and music script.