If algorithms are described then note any bugs in them. Note any incorrect or inconsistent use of terminology. Note any discrepancy between algorithms described and worked exam- ples that illustrate them. If experimental work is described then check the methodology of the experiments and ensure that they justify any conclusions drawn from them. Even if there are no technical errors there may be gaps or faults in informal arguments or unjustified assertions made.
Work is unoriginal if published either by the authors or by someone else.
Often the situation is not quite clear-cut, e.g. the work is a slight advance on earlier work, or the presentation makes comparison difficult. Addition of such a comparison might be made a condition of acceptance. Identify the nature of the contribution before deciding on originality. For instance, a technique might be well-known, but the originality may lie in a novel application of it or in an experimental comparison with some other technique. Presentation covers overall organization, readability and the use of English.