By: Dr. Catherine McGeoch | Senior Scientist (Retired) | D-Wave
An important but little recognized challenge facing the quantum industry today is not technical—it’s semantic.
Across quantum computing and optimization, researchers and practitioners debate concepts such as quantum advantage, performance speedup, and even what qualifies as a computer. But many of the industry’s most persistent disagreements are not actually about experimental results or hardware capabilities. They are about the meanings of the words themselves.
Philosophers of science call this phenomenon semantic discord: it refers to arguments that appear to be about facts but are really about definitions. In an emerging, interdisciplinary field such as quantum technology, semantic discord is unavoidable.
Quantum computing brings together experts in the fields of physics, computer science, engineering, mathematics, and operations research, each with their own technical vocabularies. As a result, the same term can mean very different things depending on who is using it.
Take the seemingly simple question: Is a quantum processing unit (QPU) a computer?
In everyday terms, the answer is obviously yes: if a device can execute programs, read inputs, and produce outputs, it’s a computer. But according to theoreticians, a QPU is just a circuit—analogous to the arithmetic logic unit [CF5] in any model of computation, which alone cannot achieve the full functionality of a universal Turing machine. Others have argued that some early noisy QPUs behaved more like random output generators than reliable computers.
These viewpoints do not dispute the underlying physics. Instead, they reflect different definitions of the word computer.
The same dynamic appears in discussions of quantum performance benchmarking. The past decade has seen scores of published benchmarking studies comparing performance of annealing-based QPUs and classical optimization solvers, which have been contributed by researchers in physics, computer science, applied fields like machine learning and operations research, and by quantum computing developers. Benchmark test design reflects one’s background and priorities: depending on how the tests are designed, it is possible to arrive at entirely different conclusions about whether a given quantum system outperforms classical methods.
Benchmarking design choices matter enormously:
Different combinations of choices can completely change outcomes. For example, in scaling studies of exact solution quality (percentage of solutions that are optimal), annealing QPUs compete with but rarely outperform classical solvers. But in studies that evaluate approximate solution quality (objective function distance from optimality) on large problems, under short time limits quantum advantages are routinely observed.
This variability creates an important challenge for the broader ecosystem. Two groups can examine the benchmarking literature and come away with completely different conclusions, not because one side misunderstands the results but because they define outperformance differently.
The debate surrounding quantum supremacy, quantum advantage, and quantum utility offers perhaps the clearest example of semantic discord in the field today. Different groups may assign the same meanings to different terms, or different meanings to the same terms. For some, demonstrating an efficient quantum computation beyond classical reach is sufficient to claim quantum supremacy. Others believe the demonstration should have practical or commercial relevance. Some prioritize comparisons against highly tuned classical solvers; others focus on comparisons to industry standards. As a result, one group may view a particular demonstration as a landmark achievement while another remains wholly unconvinced.
The disagreement is often less about what the hardware achieved and more about what the industry should call that achievement. While these debates can be frustrating, they are a natural sign of a rapidly evolving field.
Quantum technology is still defining itself. Standards are emerging. Benchmarking frameworks are maturing. Industry expectations are evolving and being negotiated across disciplines and stakeholder groups, exacerbating the need for clear communication.
One practical way to reduce semantic discord is surprisingly simple: In each instance, define terms explicitly. When discussing concepts such as quantum performance or scalability, start with a clear explanation of what those words mean in your specific framework. Doing so can quickly transform an unproductive argument into a constructive technical discussion, helping create better alignment and reducing time spent on debates that may be impossible to resolve.
Of course, some disagreements will remain. Semantic debates rarely disappear entirely. (Anyone who has participated in arguments like “Is a hot dog a sandwich?” or “Is cereal soup?” knows that definitions can be endlessly debatable.)
As the quantum ecosystem continues to grow, the industry’s ability to communicate clearly across disciplines may be just as important as advances in hardware performance itself. Sometimes the hardest challenge in quantum computing is not building the technology; it’s agreeing on what it all means.