Similar to the Indian tradition, Chinese philology, "Xiaoxue" (小學 "elementary studies"), began as an aid to understanding classics in the Han dynasty (c. 3rd century BCE). "Xiaoxue" came to be divided into three branches: "Xungu" (訓詁 "exegesis"), "Wenzi" (文字 "script and "Yinyun" (音韻 "[study of sounds") and reached its golden age in the 17th century CE (Qing Dynasty). The glossary "Erya" (c. 3rd century BCE), comparable to the Indian "Nighantu", is regarded as the first linguistic work in China. "Shuowen Jiezi" (c. 2nd century BCE), the first Chinese dictionary, classifies Chinese characters by radicals, a practice that would be followed by most subsequent lexicographers. Two more pioneering works produced during the Han Dynasty are "Fangyan", the first Chinese work concerning dialects, and "Shiming", devoted to etymology.