Is there material that does not contribute to one of the elements listed above?
If so, this may be material that you will want to consider deleting or moving.
You should then go on to explain why more work was necessary (your work, of course.) Quarantine your observations from your interpretations.
The writer must make it crystal clear to the reader which statements are observation and which are interpretation.
Because of the literature explosion, papers more skimmed than read.
Skimming involves reading the abstract, and looking at the figures and figure captions.
"Show them, don't just tell them…" Ideally, every result claimed in the text should be documented with data, usually data presented in tables or figures.
If there are no data provided to support a given statement of result or observation, consider adding more data, or deleting the unsupported "observation." Examine figure(s) or table(s) pertaining to the result(s).
This section should be rich in references to similar work and background needed to interpret results.
However, interpretation/discussion section(s) are often too long and verbose.