Using transitional words and phrases
helps papers read more smoothly.  
They provide logical organization and understandability
and improve the connections and transitions between thoughts
A coherent paper allows the reader
to flow from the first supporting point to the last.
Transitions indicate relations,
whether within a sentence, paragraph, or paper.
This list illustrates "relationships" between ideas,
followed by words and phrases that can connect them.
Addition:
also, again, as well as, besides, coupled with, furthermore, in addition, likewise, moreover, similarly
Consequence:
accordingly, as a result, consequently, for this reason, for this purpose, 
hence, otherwise, so then, subsequently, therefore, thus, thereupon, wherefore
Generalizing:
as a rule, as usual, for the most part,
generally, generally speaking, ordinarily, usually
Exemplifying:
chiefly, especially, for instance, in particular, markedly, namely, 
particularly,  including, specifically, such as
Illustration:
for example, for instance, for one thing, as an illustration, 
illustrated with, as an example, in this case
Emphasis
above all, chiefly, with attention to, especially, particularly, singularly
Similarity:
comparatively, coupled with, correspondingly, identically, likewise, similar, moreover, together with
Exception:
aside from, barring, besides, except, excepting, excluding, exclusive of, other than, outside of, save
Restatement:
in essence, in other words, namely, that is, that is to say, 
in short, in brief, to put it differently
Contrast and Comparison:
contrast, by the same token, conversely, instead, likewise,
on one hand, on the other hand, on the contrary, rather,
similarly, yet, but, however, still, nevertheless, in contrast
Sequence:
at first, first of all, to begin with, in the first place, at the same time,
for now, for the time being, the next step, in time, in turn, later on,
meanwhile, next, then, soon, the meantime, later, while, earlier,
simultaneously, afterward, in conclusion, with this in mind, 
Summarizing:
after all, all in all, all things considered, briefly, by and large, in any case, in any event, 
in brief, in conclusion, on the whole, in short, in summary, in the final analysis, 
in the long run, on balance, to sum up, to summarize, finally
Diversion:
by the way, incidentally
Direction:
here, there, over there, beyond, nearly, opposite, under, above,
to the left, to the right, in the distance