Likelihood of Success in Percentage Terms; What Does It Really Mean?

Anyone who practices trademark prosecution has likely faced that most dreaded of questions: "what is the percentage likelihood that you can overcome the examiner's objection". Indeed, some of you may have put that question (or have been made to do so by your client) to your associate. I have thought long and hard about this, both from the vantage of being asked it as well as seeking the information from others. Here are some of my thoughts.

First and foremost, there is the issue of applying numerical percentages to an inherently uncertain activity. Frank Knight, the famous economist from the University of Chicago, taught us nearly 90 years ago that there is a fundamental difference between uncertainty and risk. In his own words:
"Uncertainty must be taken in a sense radically distinct from the familiar notion of Risk, from which it has never been properly separated.... The essential fact is that 'risk' means in some cases a quantity susceptible of measurement, while at other times it is something distinctly not of this character; and there are far-reaching and crucial differences in the bearings of the phenomena depending on which of the two is really present and operating.... It will appear that a measurable uncertainty, or 'risk' proper, as we shall use the term, is so far different from an unmeasurable one that it is not in effect an uncertainty at all."
In other words, uncertainty is characterized by being incalculable, as opposed to risk, for a which a meaningful calculation is possible (à la probability). In truth, the decade's most prominent curmudgeon, Nassim Nicholas Taleb, expressed skepticism over whether any risk can really be calculated. Thus, in The Black Swan, Taleb famously questioned Knightian uncertainty in the following words:
"In real life you do not know the odds; you need to discover them, and the sources of uncertainty are not defined. Economists, who do not consider what was found by noneconomists worthwhile, draw an artificial distinction between Knightian risk (which you can compute) and Knightian uncertainty (which you cannot compute), after one Frank Knight, who rediscovered the notion of unknown uncertainty and did a lot of thinking but perhaps never took risks, or perhaps lived in the vicinity of a casino. Had he taken financial or economic risk he would have realized that these "computable" risks are largely absent from real life! They are laboratory contraptions."
Whether or not one accepts Knight's or Taleb's view of things on this point, the

upshot for us is the same. There is something deeply troubling about being asked to give a percentage to the likelihood of success of a trademark application, an activity that certainly lies within the broad field of uncertainty.


Rare is the slam dunk rejection ("Coca Cola" for soft drinks; "table" for tables) or slam dunk acceptance ("UBUGUGU for any goods or services). Not infrequently, the tendency of a trademark owner is to select a mark that, at least obliquely, seeks to relate to the goods or services to which the mark is being used. As such, the ultimate fate of such a mark upon examination or the like (depending upon whether the jurisdiction addresses relative grounds only upon a challenge by a third party) will usually fall within the parameters of Knightian uncertainty. And yet--there I am, being asked (or asking) for a percentage view of likeklihood of success.

For students of psychological measurement, it would be a fascinating study to map out the parameters by which we trademark practitioners give a percentage estimate for likelihood of registration success. Some of these considerations may be the following:

  1. How broad a band are we setting when we use the ubiqitous 50/50 as the anchor?
  2. Do we err on the side of overstating or understating the likelihood of success?
  3. If so, what are the factors that lead us to overstate or understate?
  4. If so, how does that tendency affect the percentage that we give?
  5. Are the percentages that we give linear or non-linear? If so, in what maner?

From the point of view of the person seeking the percentage, the focus is on how such person uses such information. To wit:

  1. Does it affect a decision to instruct the associate to proceed with prosecution?
  2. If so, how is the information used to reach the decision?
  3. Does it matter if the percentage given by the associate is accompanied by a narrative that further describes the factors underlying the likelihood of sucess?
  4. Does the decision-making of the instructing party differ, depending upon whether the request for a percentage estimate comes from the instructing party or the client?

Questions galore--any thoughts or guidance would be most welcome.



Questions, questions, questions