One disadvantage of a niche field like patent law is that misinformation amongst the general public is as common as a Form P.4, while a sound understanding of patents is as rare as a compulsory license in South Africa. 

To most, the term “patent” is not completely foreign. However, it usually conjures up fleeting memories of the reality TV show “Dragons’ Den” and then, well, not much else. It comes as no surprise, therefore, that patents and the protection they provide are shrouded in myths and misconceptions. 

One such misconception lies within the very heart of the patent industry and undermines public confidence in the patent system as it spreads the idea that avoiding patent infringement is simply a matter of tweaking an invention by some arbitrary percentage. To those holding this belief, patent protection seems pointless considering the high price tag that it carries. Such an attitude fuels their conviction that the patent system is merely a scheme to make scientists-turned-lawyers wealthy, while providing minimal benefits to inventors themselves. When professionals in this industry are faced with this scenario, the instinctive response is usually a defensive one – which is understandable since the time taken to qualify in this profession is comparable to that of a medical specialist or neuroscientist. In an effort to uphold the integrity of the public’s perception of patents, it is tempting to resort to lengthy and complicated explanations, which in most cases, leaves the listener feeling even more bewildered and uneducated than they did before. Even worse, the listener may take this defensive approach as affirmation that their beliefs are correct. 

The solution lies in providing explanations in a way that re-establishes the faith in the patent industry. Starting by remembering that the likelihood of inventors having an in-depth knowledge of patent law is slim, this misconception can be exposed for what it is: absurd. No such percentage rule exists in the world of patents. The patent industry does not lie in the black and white realm of simple mathematics; instead, it resides in an abstract, yet colourful world of dictionary definitions floating around trying to bound undefined shapes – incidentally, the world in which patent attorneys find themselves most comfortable. The question of patent infringement cannot be answered by numerical methods but is instead determined by a conceptual piece-by-piece analysis of a patent claim and an allegedly infringing product, with a sharp focus on word choice. This might seem obvious to a patent attorney, but ironically, in this field, “obviousness” is a word loaded with subjective meaning. 

The key to understanding patent infringement is intertwined with a patent’s claims. Patent attorneys are intimately familiar with claims, having spent countless hours learning to craft and interpret them. To the layperson, however, a claim is just a bunch of bizarre words strung together into an unusually long sentence. 

The experience of a furrowed brow and rise in blood pressure while reviewing some of an inventor’s amendments to claims is fairly common – especially when the inventor needs to be convinced that certain words actually exist; like “adsorption”, “juxtapose”, “bifurcation” and “foraminous”, to name but a few. Unsurprisingly, this is the root of the percentage change fallacy and in order to quell this false belief, inventors should be given a better idea of the intricacies embedded in the art of claim drafting. 

It turns out that a simple visual analogy for what a claim is and how infringement is tested is fairly tough to conjure up. Some ideas include a food recipe, a lock and key, overlapping Venn diagrams, or perhaps a ten-dimensional hypervolume, for the brave at heart. Possibly the simplest analogy would be to think of an invention and the claim that defines it, as a jigsaw puzzle made up of specific pieces, where each piece represents an integer of the claim or part of the invention. These individual pieces fit together beautifully to create an image representing the claim and the invention itself. If a product, also thought of as a jigsaw puzzle defined by its own pieces, includes all the necessary pieces to produce the same image as the invention’s puzzle, infringement would take place. Of course, infringement would still take place even if the product has additional pieces – i.e. despite an extra puzzle piece, the image created by the product’s puzzle would still match the invention’s puzzle. On the other hand, if the product’s puzzle does not produce the same image, either because a piece is missing or it has a piece that fits but has a different image on it, there would be no infringement. 

However, when attempting to visualise the broadness and scope of a claim and its parts, the jigsaw puzzle analogy falls somewhat short. The analogy requires another layer: pieces that are filled to varying degrees, as illustrated below. 

With this added variable, the broadness of an integer can be visualised – the less a piece is filled in, the broader its scope. Naturally, a piece filled in completely would represent an extremely specific integer, narrowing the claim’s scope. The image below illustrates how the same integer could be described in different ways with varying degrees of broadness. 

When drafting patent claims, great care is taken to maximise broadness yet ensure that the invention as described remains clear. Applying this to the analogy, drafters attempt to construct pieces which show as little as possible while ensuring that the image produced when the puzzle is completed is easily discernible. The more detail included in the image produced by the puzzle, the narrower the scope of the claim becomes, which would make it easier for others to change their product’s puzzle piece sufficiently to create a new image, or simply, avoid infringement. 

That being said, two more aspects guide the construction of an invention’s puzzle pieces: novelty and inventive step. For novelty, the image created by the pieces of the invention’s puzzle must be different from all those that came before. A “Goldilocks” amount of detail must be added to provide the limitation necessary for the claim to be new – not too broad, not too narrow, but just right. As for inventive step, the added detail itself or the final image produced must be impactful on the human mind, somehow. Although the actual invention provides parameters within which to operate, this detail can be just as tricky to define as it is to paint a sunrise. All the variables of the image must be considered: the size, shape, colour, and placement of the sun, the type of landscape, which elements are contained in the landscape, how the sun’s light influences that landscape and its elements – the list can go on forever. This is what makes drafting patent specifications and claims as challenging as it is. 

When it comes to infringement, it may seem simple to compare two images with each other – and in some cases, it is indeed simple – but in others, the comparison equates to a game of spot-the-difference between two satellite images of a desert. In practice, this method of detailed analysis and comparison is known as “construing” the claims of a patent, meaning to “interpret (a word or action) in a particular way,” or to “analyse the syntax of (a text, sentence, or word),” according to the Oxford English Dictionary. Therefore, when the claims of a patent are construed, the specific words used, and the meanings attached to them are analysed and interpreted individually and within the context of the invention as a whole. 

Ultimately, the problem at the core of the percentage change fallacy is not the concept of patents themselves, but rather a lack of understanding of what patent attorneys spend years perfecting. It is all too easy to blame a patent attorney for an invalidated patent or avoided infringement when the complexities of the profession are reduced to arbitrary metrics or misunderstood criteria. Given that patent attorneys revel in technically defining the abstract, to maintain public faith in the patent industry, inventors should be taught and reminded of the “basics” in a way that is simple enough to ensure that the reality of the profession prevails over any misconceptions. By using analogies like the jigsaw puzzle to aid in conveying the complicated world of patent infringement and claim drafting in a simpler, albeit possibly flawed, manner, perhaps the value of the patent system will be appreciated for the wonderful beast that it is.