Learn English – untypical, atypical, nontypical

adjectivesnegationprefixesun-notword-choice

I'm trying to label customer data with a word describing how typical they are. There is basically 3 possible values: typical, temporarily untypical, untypical. But I'm not sure if "untypical" is the correct word. Should it rather be "atypical" or "nontypical"? Does it matter if we're talking about technical things? Is there a difference for british and american english?

EDIT:

Considering the recent activity and interest, I'll give an explanation of what we're doing. We're trying to predict customer behaviour (product consumption per day). To do this, we have a long history of measured product consumption for every customer. When we get those values, we label them as either "typical", "atypical", "shortterm typical" (this is our solution to the question. I know I wrote "temporarily untypical" earlier, that was wrong, sorry).

When we predict future behaviour, we usually only use the "typical" values from the past. The "atypical" values are considered correct, but not a good information to predict future behaviour. The "shortterm typical" values are for special times. For example when a customer is in an economic crisis, his yesterday's product consumption will be good information to predict his product consumption for tomorrow; but it is not good information to predict his product consumption in 2-3 years.

Best Answer

Atypical is by far the most common of the three, as confirmed in a Google Ngram search, so that would be my suggestion.

Untypical is apparently most often used in the phrase "not untypical". Another Google Ngram search supports this.

Nontypical, and with a hyphen non-typical, are hardly used at all. I cannot find an entry for either in any popular online dictionary.

This Ask the Editor response has more details, which basically echo what I said. I'll quote it below:

Because the prefixes a- and un- can both mean not, atypical and untypical have the same meaning: not typical, not usual or [not] normal. However, the contexts in which these two words are used are different. There is also a 3rd choice with the same meaning, which will be discussed below.

1. atypical Atypical is the most common of these choices. However, it is used mostly in formal language about medical topics, as in these examples:

  • These cases were atypical because the patients were diabetic.

  • The biopsy showed a few atypical cells.

2. untypical Untypical is used much less often than atypical, and it is becoming rarer. When untypical is used, it is most often after the word not, as in this example:

  • The summer weather arrived suddenly, which is not untypical for New Orleans. (not + untypical = typical)

3. not typical The phrase not typical is used more than untypical. Not typical can be used in a variety of contexts to talk about all kinds of topics, as shown in these examples:

  • This was not typical behavior for a 10-year-old.

  • It was not a typical business meeting.

  • This is not typical weather for Miami.