Incident vs. Incidence – What’s the Difference?

In formal writing situations, many writers attempt to make their writing overly technical or complex. This desire is understandable—academic and professional writing deal with more technical and complex topics than everyday English, and in these highly competitive settings, young writers often feel pressure to make themselves stand out from the crowd.

While elevated language has its place, writers must still be careful in areas like word choice and sentence structure.

The homophones incidents and incidence both refer to multiple events, but there is an important difference in their meanings when they are used correctly. In academic and professional scenarios, you will need to remember which is which.

What is the Difference Between Incident and Incidence?

In this post, I will compare incident vs incidence. I will use each of these words in at least one example sentence, so you can see them in context. Plus, I will show you a helpful memory tool that will allow you to choose incidence or incident correctly every time.

When to Use Incident

What does incident mean? Incident is a noun. It means an event or occurrence. Just about anything that happens could be considered an incident, but in everyday English, it usually refers to something that is distressing or problematic.

For example,

• Kelsey is back to work, but ever since the incident, she has been quiet and withdrawn.
• “We had a little incident in the porta-potty,” said the toddler’s father.
• The incident in 2014 could have led to a serious loss of military technology, officials told the paper. –BBC News

The plural form of incident is incidents, which is a homophone of incidence. That is part of the reason these two words are confusing.

Note: the plural form of incident is not incidences.

When to Use Incidence

What does incidence mean? Incidence is also a noun. It refers to the rate of occurrence for something that happens regularly. A crime that has a high incidence is one that is committed often. Likewise, an intersection with a high incidence of vehicle accidents should be evaluated by a traffic committee.

Here are a few sentences that show incidence in context,

• The high incidence of problematic behavior in structured settings is evidence that Colten struggles with focused attention and task perseverance.
• Corrine has been tracking the incidence of attempted theft at her grocery store.
• Significantly, the decline in new dementia cases, or incidence, occurred only with people who had at least a high school diploma. –The New York Times

Trick to Remember the Difference

Since incidents and incidence are homophones, there is confusion on when to use each. Particularly in academic contexts, when young writers have incentive to write in an overly formal or technical style, incidence is often misused for incidents.

• If you are referring to an event, use incident.
• For more than one event, use its plural, incidents.
• Use incidence only when referring to an event’s rate of occurrence over time.

Since incidents is a plural, and ends in the characteristic -s, you can use the plural suffix as a reminder that incidents refers to events themselves, rather than rate or frequency.

Summary

Is it incident or incidence? Incidence is a homophone of incidents, which causes confusion.

• An incident is one event.
• If the event happens more than once, incidence is the rate of occurrence for that event.

You should only use incidence when referring to the rate or frequency of an event, and incident or incidents when referring to the events themselves.