Avoid direct questions (ending with a question mark)

Direct questions, as in (1a), are effective in oral presentations because they engage audience members and focus their attention. However, these questions often reduce the formality of scientific writing and give the text a more "chatty" impression. The alternatives in (1b) and (1c) still involve a question and the word why, but these are now formed as indirect questions, which are more formal.

Less formal (direct question):

(1a) Why has the use of alternative therapies increased?  

More formal (indirect question):

(1b) It remains unclear why the use of alternative therapies has increased.

(1c) Previous research has offered several theories as to why the use of alternative therapies has increased.

Grammar note: As indicated by the underlined words, the word order in direct questions (1a) differs from the word order in indirect questions (1b) and (1c). The punctuation is also different: direct questions have a question mark, whereas an indirect question is part of a sentence which ends with a full stop.

Can I write my research question as a direct question?

In some research papers and degree projects, you will see the research question written out as a direct question at the end of the Introduction. This can be a good way of highlighting your specific question; however, in running text, direct questions should be avoided.