專利指標是用以衡量專利價值的一種方式，常應用於評估企業或公司的技術能力，主要分為二類，包含量之指標，以及質之指標，為度量專利資訊的重要參考。專利分類號為專利書目資料中重要的資訊，能夠代表不同的技術領域，賦予專利不同的專利分類就可對其進行分類，同時，過去也曾有文獻認為能夠以專利分類號的數量來代表專利廣度，進而測量專利的質量，即將專利分類號視為質之專利指標之一。迄今仍有許多學者認同這種說法，並沿用此觀念進行研究。然而，本研究對此學說抱有疑慮，認為專利分類號有不同的系統，不同的分類系統又皆有階層關係，此外，無論是同階層或不同階層之間似乎也有迥異的涵蓋範圍大小。因此本研究希望能夠藉由已被認同為專利指標之一的專利被引用數來驗證專利分類號是否能夠真正反映專利的價值。
本研究首先以觀察個案的狀況來決定要採取的分析方式，發現不同階層的情況可能不同，且樣本數太小的話容易被侷限在特定領域，或是結果會有所偏頗無法看出整體趨勢。因此最後本研究決定採用大數據分析方式，以美國資料庫在2007年、2009年、2011年公告的所有發明專利作為研究對象，來探討專利分類號與專利被引用數之間的關聯性。在專利分類號的選用上，會分別擷取3階、4階、5階三種階層，採取對照不同階層來觀察的方式進行。另一方面，被引用數數據則是直接採用先前研究已整理之資料，比對三個不同年份所產生之結果是否相似。經過初步分析，本研究發現兩者之間似乎展現其中之一數量漸增或漸減時，另一者也會相對增加或減少。更進一步運用統計軟體SPSS進行雙變數間的相關係數分析後，再經過一些調整，最後再以關聯性統計檢驗得出分析的專利之分類號數若落在特定區間時，專利分類號數與被引用數間確實有關聯性的結論，並且兩變數間的關聯性是呈正相關，即分類號數確實可作為專利指標之一，能夠反映專利的某種品值或價值。

Patent Index is a way to measure the value of patents, often used to evaluate the technical capacity of enterprise or company, mainly divided into two categories comprising the amount index and the quality index. It is also an important reference to measure patent information. Patent Classification is one of the patent bibliographic information and represents different technical fields. Patents assigned different patent classification can be classified; meanwhile, some researches think that the number of patent classification can represent patent scope and further measure the quality of patents. So far, there are many scholars agree with this statement, and continue to apply this concept in their study. However, the present study have doubts about this hypothesize since there are different patent classification systems and all of them divided into many classes. Therefore, this study hope to verify whether there is a correlation between patent classification and patent citations, which is identified as one of the patent indicators.
In this study, big data analysis methods is been used. The data are granted patents in 2007, 2009, 2011 from the United State Patent and Trademark Office database. The selection of the Patent Class are class three , class four, and class five. In addition, the data of patent citation is from previous studies. Compared with three different years and three different class of patent classification, observing the relation between the number of patent classification and the amount of patent citations. After the preliminary analysis, the study found that the two variables seem to be increasing or decreasing together by the correlation coefficient analysis of statistical software SPSS. In another word, the conclusion shows that if the number of patent classification of analysis data falls in a certain interval, two variables are certainly highly positive correlation. Thus, patent classification is one of the patent indexes and can reflect certain values of patent.

英文部份
Lerner, J. (1991). The impact of patent scope: an empirical examination of new biotechnology firms. Retrieved from http://belfercenter.hks.harvard.edu/files/disc_paper_91_04.pdf
Lerner, J. (1994). The importance of patent scope: an empirical analysis. The RAND Journal of Economics, 25(2), 319-333.
Ernst, H. (2003). Patent information for strategic technology management. World patent information, 25(3), 233-242.
Allison, J. R., Lemley, M. A., Moore, K. A., & Trunkey, R. D. (2004). Valuable Patents. Georgetown Law Journal, 92(3), 435-1309.
Kim, D. J., & Kogut, B. (1996). Technological platforms and diversification. Organization Science, 7(3), 283-301.
EPO&USPTO. (2011). CPC Presentation.
Alexandria. (2012). General Introduction into CPC. Retrieved from http://www.cooperativepatentclassification.org/publications/UsptoUserDayGeneralIntro.pdf
Griliches, Z. (1990). Patent statistics as economic indicators: a survey. National Bureau of Economic Research.
Silverman, B. S. (1999). Technological resources and the direction of corporate diversification: Toward an integration of the resource-based view and transaction cost economics. Management Science, 45(8), 1109-1124.
Trajtenberg, M., Henderson, R., & Jaffe, A. (1997). University versus corporate patents: A window on the basicness of invention. Economics of Innovation and new technology, 5(1), 19-50.
Breschi, S., Lissoni, F., & Malerba, F. (2003). Knowledge-relatedness in firm technological diversification. Research Policy, 32(1), 69-87.
Garcia-Vega, M. (2006). Does technological diversification promote innovation?: An empirical analysis for European firms. Research Policy, 35(2), 230-246.
Ozman, M. (2007). Breadth and depth of main technology fields: an empirical investigation using patent data. Science and Technology Policies Research Center Working Paper Series, 7(1).
Leten, B., Belderbos, R., & Van Looy, B. (2007). Technological diversification, coherence, and performance of firms. Journal of Product Innovation Management, 24(6), 567-579.
Chen, J. H., Jang, S.-L., & Wen, S. H. (2010). Measuring technological diversification: identifying the effects of patent scale and patent scope. Scientometrics, 84(1), 265-275.
Su, H. N., Chen, C. M. L., & Lee, P. C. (2012). Patent litigation precaution method: analyzing characteristics of US litigated and non-litigated patents from 1976 to 2010. Scientometrics, 92(1), 181-195.
Hu, X., & Rousseau, R. (2015). A simple approach to describe a company’s innovative activities and their technological breadth. Scientometrics, 102(2), 1401-1411.
Molina, E. P. (2014). The Technological Roots of Computer Graphics. IEEE annals of the history of computing, 36(3), 30-41.
Trajtenberg, M. (1990). A penny for your quotes: patent citations and the value of innovations. The Rand Journal of Economics, 21(1), 172-187.

中文部份
陳達仁、黃慕萱（民91）。 專利資訊與專利檢索。文華圖書館管理資訊公司。
朱雪忠、漆苏（民100）。美国专利改革法案内容及其影响评析。知识产权，第9期，79-89。
經濟部智慧財產局（民101）。 合作專利分類(CPC)的最新進展。Retrieved from https://www.tipo.gov.tw/ct.asp?xItem=318848&ctNode=7124&mp=1
黃慕萱（民94）。從專利引用與技術分類探討美國高科技公司之發展歷程與趨勢。Retrieved from http://ntur.lib.ntu.edu.tw/bitstream/246246/20436/1/932413H
賴奎魁、吳曉君、張善斌（民94）。建立產業專利分類系統－共同引証分析的觀點。管理學報，第22卷第2期，261-276。
許旭昇（民94）。專利組合分析方法之建構—以磁阻性隨機存取記憶體為例。真理大學企業管理學系所碩士論文。
周永銘（民95）。應用專利分類號於專利技術叢集化之研究。臺灣大學機械工程學研究所碩士論文。
陳省三（民95）。淺談專利分類之發展與應用。萬國法律，第148期，16-21。
阮明淑、梁峻齊（民98）。專利指標發展研究。圖書館學與資訊科學，第35卷第2期，88-106。
潘明禎（民99）。技術多角化與廠商績效之間的關聯性─以智慧資本為調節變數。中興大學企業管理學系所碩士論文。
許珂、陳向東（民99）。基於專利技術寬度測度的專利價值研究。科學學研究，第28卷第2期，202-210。
王玉娟（民100）。基於專利技術寬度測度的外資在華合作專利價值研究——以生物技術領域為例。科技和產業，第11卷第6期，86-89。
鄭祥瑞（民104）。忽略專利公開案的引用對專利引用分析之影響研究。臺灣科技大學專利研究所碩士論文。
陳景堂（民92）。統計分析: SPSS for Windows入門與應用。儒林圖書有限公司。
陳淼勝、李德治（民105）。 統計學概論。前程文化。