In your presentation, usually on one slide at the beginning in the motivation part, you compare your method to 1) methods widely accepted and recognized as adequate by the people in the field, or 2) the first (and now dated) method invented by the pioneer in the field or 3) only those selected methods that perform worse than yours. Actually, let me take back point 3 because you would never do that since all scientists display great intellectual honesty. You would never keep silent on methods that perform better than yours in certain aspects, or you would never filter out from your evaluation criteria the points where your method does not perform as well as other methods. After all, the reason why you can list the weaknesses of other people's methods is because they had the intellectual honesty to recognize them in their papers, or because you have the irrefutable evidence to support your assertions somewhere in your paper.
So what is wrong with comparing your method to other methods to claim superiority?
1) Because PowerPoint does not give you much space to illustrate or justify each limitation (font size 30 is restrictive), you list them all in bullet point form, relying mostly on the use of adverbs, adjectives, and judgmental verbs to validate your claim of superiority: slow, computationally intensive, limited, complex, expensive, fails to, suffers from…
2) In the room, attracted by your title, chances are you will find the very people whose methods you critique: the experts, the “related work” folks. They came to learn from you, not to have their contribution to the field questioned or featured in a poor light.
3) Your summary judgmental evaluation on their methods is probably based on old reading, and the state of the art may have progressed since then, thus rendering your evaluation inaccurate.
As a result, your comparison strikes a match that will light the short fuse of the bomb bound to explode during your Q&A. These scientists you indirectly attacked will dispute or question your claims; after all, any adjective or adverb is a claim and a claim deserves fair justification before it can be accepted. Because the reputation of their work is at stake, they will bring you onto their turf – a place you know little about – and they will take great pleasure to demonstrate how inaccurate are your claims!
So here are your solutions:
If you have to expose limitations:
1) Choose the main limitation, illustrate it visually and scientifically so that it cannot be contested, and make sure you clearly define the scope under which that limitation applies.
2) Find a way to praise the method whose limitation you are presenting.
But you do not have to expose limitations. If the experts are in the room, they will ask questions to assess how well your method is likely to work in their field (and this is good!). If you do not know, you will be able to deflect such questions on the grounds that you have not tried it on their problems. At the same time, you will welcome their interest in your work and propose to collaborate with them to extend the application range of your method to their work– or to discover its boundaries (don’t say limitations!)
If you do not know how well your method would perform on untried problems, be conservative. Do not say “This method should also work in your field, or on your problem”. They could call your bluff and ask “On what ground do you form this opinion?” If the experts in the audience detect what they consider unwarranted evidence in your answer, you will be seen as a scientist of much enthusiasm but somewhat delusional and lacking experience.
Look at the photo above, how much bigger the orange seems depends a lot on the perspective, doesn’t it? An architect who has studied perspective would have a more accurate answer than a researcher in life science. But someone who has handled both fruit would have the best answer.
By Jean-luc Lebrun