A cover letter can be used for many different
things (job applications etc).
On this course the cover letter is intended for
manuscript submissions.
It is important to be polite, use the name
of the person you are writing to if possible.
Summarize the main findings of your work,
and describe why this would be interesting for
the readers of the journal. Here it of course helps
if you have a major finding.
One school of cover letter writing insists
you make it loooong, about two-three pages.
The theory is that you thereby force the Editor to
commit his/her time to it, and that this makes a
subconscious impact of that it is somehow important.
By contrast, a very short letter is more easily forgotten
and dismissed. But you need also to check the Instructions
for Authors, there may be limits or guidelines you should adhere to.
I am more sort of in favor of the short cover letter,
focused on the main, strong findings, so that you
don't bore the Editor to death with fluff.
Here is a brief template:
'Dear Sirs/Madams,
enclosed please find a manuscript entitled 'xxxxxxxxx',
where we show for the first time that blablabla.
These findings should be of interest for readers of
The Journal, especially for those in the field of yyyyyyyyy.
Others have previously shown that blablabla, however,
here we blablabla and blablabla.
This is in contrast with the current research of
blablabla and blablabla.
Looking forward to hearing from you.
Sincerely, ...'
When re-submitting a revised manuscript, you also add
a cover letter, but now typically appending an itemized rebuttal list,
addressing the concerns of the reviewers, point-by-point.
You can find some examples of such on the previous page.
