这种图示将文字教材贮存的大量知识信息经过精心提炼 ,以单词、短语、数码、符号、颜色等信号表现形式 ,依照知识的纵向关系和横向关系 ,通过科学的编排组合 ,形成大小不同的系列直观视觉图象 ,体现了少而精的原则 ,体现了直观形象的特点。视觉信号表现知识内容 ,图象体现整体 This type of illustration carefully abstracts a large amount of knowledge stored in text materials and uses signal expressions such as words, phrases, numbers, symbols, and colors to form different sizes according to the vertical and horizontal relationships of knowledge, through scientific arrangement and combination. The series of intuitive visual images embodies the principle of less and more refined, reflecting the characteristics of intuitive images. The visual signal expresses knowledge content, the image reflects the whole