In 2006, the International Astronomical Union approved a new definition of planet. Pluto, considered a planet since its discovery in 1930, does not meet all of the requirements of this new definition and so was reclassified as a dwarf planet.

The decision sparked heated discussion and debate among scholars and scientists, but according to Dr. Jeffrey Parsons, professor and associate dean (research) in the Faculty of Business, the real controversy should be the assumptions we make about classification.

In an essay published in the Oct. 23 issue of Nature, Dr. Parsons and Yair Wand, professor with the University of British Columbia, argue that ill-conceived classifications can prove futile and even harmful to scientific progress.

“At best, they might result in wasted time spent arguing over terminology. More seriously, they can misdirect research efforts and funding. And at worst, in cases such as the misclassification of medical conditions, the result can be serious harm, including misdiagnosis, improper treatment and even death,” they explain in the essay.

Drs. Parsons and Wand were inspired to write the essay by their work on the importance of classification in computerized information systems. The difficulties in organizing data in ways that are useful and acceptable to different users of the data are immense.

The basic problem is that different classifications are useful for different purposes. Their work on the usefulness of supporting alternative classification schemes led them to realize that the same issues occur in other areas, including many scientific disciplines.

Dr. Parsons suggests that, as a variety of relationships occur in nature and different ones can be of interest to scientists for different objectives, different classification schemes can coexist.

“For example, classes of bodies in our Solar System can be defined in many ways: reflecting interrelationships associated with how they were formed, their physical characteristics, or even whether they have an environment that supports life,” he said. “Each of these definitions is useful for different reasons.”

Here on earth, classification systems are used everywhere, from the folder systems that most of us use to organize e-mail to diagnosing illness. Dr. Parsons maintains that we must avoid the trap of imposing a categorization where it does not fit. The consequences of doing otherwise can range from annoyance (such as when we forget where we put a particular email) to disaster (such as when we misdiagnose and mistreat an illness).

For example, in the 1950s, ulcers were classified as a disease caused by environmental factors, as opposed to genetic or pathogenic. A decade earlier there had been indications that peptic ulcers could be cured by antibiotics, but the widespread belief that bacteria could not live in the acidic environment of the stomach prevented scientists and doctors from accepting the true etiology. In 1982  the bacteria H. pylori was strongly implicated as a possible major cause of ulcers but it was not until 1994 that antibiotics were recommended for treatment. In 2005, this led to the awarding of the Nobel Prize in medicine for the discovery.

Dr. Parsons says this incorrect classification of a medical condition not only hindered the discovery of causative factor but also delayed its acceptance.

“The main problem was the misattribution of the property ‘cannot grow in the acidity of the stomach’ to the class of bacteria. Reevaluating this fundamental property involved a major mind-shift that was difficult to accept,” he explained.

Dr. Ray Gosine, Memorial's vice-president (research), Pro Tempore, believes that the potential for this work to have impact beyond a specific discipline is substantial.

“That Dr. Parsons’ work, which has its roots in business, is being recognized for its potential impact on the natural sciences, and beyond I’m sure, is an example of how advances in research increasingly depend upon and benefit from interdisciplinary approaches and analysis,” he said.

“Nature is among the most prestigious and consequently difficult journals in which to publish scholarly results. This achievement brings credit to Dr. Parsons, the Faculty of Business and to Memorial University in general.”

To read A Question of Class, visit Nature online, http://www.nature.com/nature/journal/v455/n7216/full/4551040a.html.