編按：基於各種技術原因，香港民研暫時擱置所有自費研究活動。不過，自去年推出的民調科普文章，將會繼續發佈。文章嘗試以淺白語言、簡短篇幅，讓讀者掌握解讀數據的方法，並以不定期形式發佈。
【民調101】百分比不易用？
幾乎所有社會科學的調查，都會以百分比來表達結果。例如最近有媒體報導：「調查顯示，38% 中小企表示，營業信心受美國總統換屆影響，其中 62% 因為美國可能對進口商品徵收新關稅，59% 因為經濟環境改變。」
這個報導準確引述數字，但以科普教育來說，我們大可以討論一下百分比基數的問題。數據顯示，38% 中小企當中的 62% 擔心美國新關稅，其實只佔受訪中小企的 24%。同樣，因為經濟環境改變而影響信心者，其實只是 38% 當中的 59% ，即 22%。雖然數字的確反映兩個因素同屬重要，但只要留意每個數字的基數，便會發現這些擔心未必屬於「主流意見」。
因此，以下的描述可能更加理想：「調查顯示，超過三分之一中小企表示，營業信心受美國總統換屆影響，尤其是美國可能對進口商品徵收新關稅，以及經濟環境改變，各佔五分之一受訪中小企。」
Editor’s Note: Due to various technical reasons, HKPORI has suspended all self-financed research activities. However, our effort to promote popular science launched last year will continue. We will use sharp plain languages to help readers grasp the skills of reading figures, and publish these short articles from time to time.
[Polling 101] Percentages Are Not Easy to Use?
In almost all social science surveys, the results are expressed in percentages. For example, a recent media report says, “The survey shows that 38% of SMEs said their business confidence was affected by the change of the U.S. President, of which 62% were due to the possibility of the U.S. imposing new tariffs on imports, and 59% were due to changes in the economic environment.”
This report is accurate in citing figures, but for the purpose of popular science education, we can discuss the issue of percentage base. The figures show that 62% among the 38% of SMEs are worried about new U.S. tariffs, which is actually only 24% of the SMEs surveyed. Similarly, those whose confidence has been affected by changes in the economic environment only accounted for 59% of the 38%, that is, 22%. While the figures do reflect that both factors are important, if one pays attention to the base of each figure, one will realize that these concerns may not necessarily be the “mainstream view”.
Therefore, the following description may be more desirable: “The survey shows that more than one-third of SMEs said their business confidence has been affected by the change of U.S. President, especially the possibility of new tariffs on imports from the U.S., as well as the change in the economic environment, each accounting for one-fifth of the SMEs interviewed.”
