廣泛學習（Extensive）和集中學習（Intensive）之間有什麼差別？這看來是個簡單的問題，通過查詢字典就能輕鬆回答。我參考了四本字典：
Merriam-Webster Unabridged（第3版）、The New Shorter Oxford English Dictionary, Webster’s New World College Dictionary（第4版）及The American Heritage Dictionary（第5版），結論如下：
Intensive＝深刻的；高度集中；徹底；詳盡的
Extensive＝範圍或數量大；深遠；全面；寬廣
您可以看出在某些意義上，這兩個詞「集中」與「廣泛」看起來像是反義詞，而在其他意義上，它們卻幾乎是同義詞：「詳盡」與「全面」。也正因為如此，作者有時會對這兩個詞感到困惑時。
這兩個詞「extensively」和「intensively」經常被誤用在錯誤的情況中。有一個現象很有趣，Google Scholar的搜索顯示，「extensively」的使用頻率高過「intensively」的三倍。讓我們一起來看看如何正確使用這兩個詞以及它們的優劣之處。
在提及專注於特定議題，且是由一小組研究人員進行的耗費心神的深入研究時，應使用「intensively」，也就是「深度」。相反地，針對描述涵蓋問題的各種面向，且可能由眾多研究小組在相對較長的時間內進行的全面研究，則應使用「extensively」，也就是「廣度」。
以下是一些這兩個副詞慣用的例子：
At an intensively studied site within the region, >90% of the dominant overstory tree species died after 15 months of depleted soil water content.
The figure illustrates a typical spine synapse that makes intimate contact with an apical dendrite of a pyramidal cell. The ultrastructure of such synapses has been intensively studied in our laboratory.
Plasma membrane transporters have been intensively studied at the mechanistic, biochemical, and molecular levels.
The asymmetric aldol condensation has been the subject of intensive study in our laboratory.
The asymmetric aldol condensation is among the most powerful reactions in synthetic organic chemistry and has been extensively studied over the past 15 years.
As surrogates for the central nervous system, peripheral samples such as blood, saliva, and skin have been extensively used in psychiatric research for decades.
Because of its importance in cholesterol biosynthesis, HMG-CoA reductase has been extensively studied.
另一個層面的問題是，有些研究議題已經經過深入且廣泛的研究，那麼這兩個詞可以在同一個句子中使用嗎？我在Google Scholar搜索中發現這類的相關例子很少，僅提出以下一個例子：
One-dimensional ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their current and future diverse technological applications.
使用「Concerning」（有關）一詞
當您在科學期刊提交論文時，您希望編輯與評審們將重點放在您的科學研究而非寫作上，您的寫作則必須正確地傳達您的意思。當然，正確的文法、標點符號與拼法很重要，但您的寫作對母語人士來說也必須讀起來很自然才行。實現此目的的一個方法是避免使用錯誤的單詞。我在編輯母語非英語的文章中經常遇到的一個問題是將「concerning」當作形容詞：
「There was a concerning trend toward long-term late deterioration in the laminectomy-alone group.」
這是錯誤的用法。
Google Scholar搜索「a concerning trend」只有大約500個搜索結果，而「an alarming trend」及「a disturbing trend」則分別有超過3500個與7000個結果。我會建議將以上句子修改為下列其中一個句子：
- There was a disturbing trend toward long-term late deterioration in the laminectomy-alone group.
- In the laminectomy-alone group, there was a trend toward long-term late deterioration, which is a cause for concern.
以下是來自已經出版文獻的一些範例：
原句：
We observed a concerning trend toward a higher incidence of postoperative bleeding in patients who received clopidogrel within 5 days of undergoing coronary artery bypass grafting.
修訂後：
We observed a worrisome trend toward a higher incidence of postoperative bleeding in patients who received clopidogrel within 5 days of undergoing coronary artery bypass grafting.
原句：
Although we have not yet seen this phenomenon with ZD1839, this is still a concerning result that will require additional study.
修訂後：
Although we have not yet seen this phenomenon with ZD1839, this alarming result will require additional study.
原句：
This concerning state of affairs led to a surge in research activities to discover and develop new antibiotics to combat the increasing threat of bacterial resistance.
修訂後：
Concern about this state of affairs led to a surge in research activities to discover and develop new antibiotics to combat the increasing threat of bacterial resistance.
這看似只是個次要的問題，但要避免引起讀者對您句意內容的爭議，請將「concerning」當作意為「in reference to」或「about」的介詞，例如：
「Controversy concerning the mechanism of cell-penetrating peptides has recently arisen」
