方以智作為一名融貫中西的學者，其科學性著作《通雅》與《物理小識》中，提出了涵蓋古今中外的兩個研究方法－－「通幾」與「質測」，認為學術研究不能脫離此二準則，進而提出「質測即藏通幾」、「通幾護質測之窮」之語，以明二者之不可偏廢，並從觀察事物變動的規律處解「通幾」，於考察事物變動的過程釋「質測」。然其「質測」為西方學術所啟發，並以為西方「通幾」之不足，故要融通二者。而《通雅》書中屢見「詳考〈質測〉」之語，亦可知方以智當有〈質測〉之作。考《物理小識》內容，即通過實際觀測所成，乃質測之學的代表作，亦與《通雅》之語「質測」相符。《物理小識》本收錄在《通雅》之後，所以單行，乃其子方中通摘出。質測既與《物理小識》密不可分，則「通幾」當有相應之作，則其實踐的代表當是《通雅》。

Fang Yi-zhi proposed two methods of observation--Tong Ji and Zhi Ce, in one of his most famous books--Tong Ya. In his opinion, Tong Ji and Zhi Ce have the same level of importance. Tong Ji is for observing the pattern of change, which is more based on the philosophy of the observation itself; while Zhi Ce focuses on the process of the changes that were inspected. The author advocates combining the benefits ofthese two methods. In Wu Li Hsiao Shi, another one of his most well-known works, he puts forth that knowledge should be found through evidence and proof. Wu Li Hsiao Shi was originally a part of Tong Ya, and were later published independently by the author's son. The representative work of Zhi Ce is Wu Li Hsiao Shi; therefore, Tong Ya would be the representative work of Tong Ji.