A paper may:

• present some results of significance in a way that demonstrates their validity and implications
• illustrate some important specific cases
• outline a new method, instrument or algorithm
• review existing work and point the way forwards
• present a critique or new interpretation of existing results or works.

In general, a paper should not:

• consist mostly of the authors’ unsupported opinions
• attack the authors behind existing results, rather than the technical validity of the results
• make unsubstantiated assertions
• present work that has been published elsewhere
• present work that is not a reasonable contribution to the field.