BizWritingTip reader: “Is it ‘incidence’ or ‘incidents?’ For example: ‘While the incidence or incidents of illegal dumping has decreased…’ ”
BizWritingTip response: This is a great question. Sometimes our English words sound so much alike it is difficult to know which one to use.
“Incidence” is a singular noun and refers to the frequency of an occurrence. It cannot be counted.
On hot summer days, there is a higher incidence of road rage.
“Incidence” may also mean the range, scope, or extent of a thing or a thing’s influence.
Scientists are studying the incidence of swine flu in North America.
We are comparing the incidences of swine flu in Canada, U.S., and Britain.
“Incidents” is a plural noun and means events or occurrences. You can count them.
There were three incidents of road rage last week.
Three hundred incidents of swine flu were documented at the university.
In the original example, I believe the reader was referring to a decrease in the number of occurrences so I would write: “While the incidents of illegal dumping have decreased…”