Evening News 24 - Refuse fire near City Hall  Arsonists sparked an emergency response after setting light to a rubbish container near City Hall on Saturday evening.

The suspects started the fire shortly after 7pm on St Giles Street.

Two fire engines were sent to the scene and firefighters used hoses to extinguish the flames.

This is an online newspaper article in its entirety. What caught my attention was the use of the word 'suspects'. By the rules of pragmatic implicature, this word is out of place in this context (we could even call it wrong or agrammatical). Suspects implies that the article is about people who have already been apprehended and it is not clear whether they had committed the crime (or legal restrictions require this unclarity). However, is we're talking about the people who really committed the crime, even though they remain unknown, the word perpetrators or vandals or arsonists (as inthe introductory sentence) would be much more appropriate. In that case, there would be no confusion.

This created an interesting garden path text (flow of inference). When I caught sight of 'suspects' I had to go back to reread the article to make sure whether they had been caught or not. And I'm still not sure. This is a quick bit of online news rather than a published and copy-edited piece (although similar errors slip through anyway) so the source of the error could be in both directions: 1. the writer misspoke or 2. forgot to mention the arrests. The former is more likely but the latter is not impossible particularly if the arrests had already been mentioned elsewhere or are being kept out.

But what is the source of this slip? Quite obviously the implicature of the word 'suspect' was overridden by the constructional conventions of journalistic prose where 'suspect' is used to describe agents in crimes as a matter of course. To use the word 'suspect' is always safer and largely understandable so the pragmatic concerns can be shelved. So what we have here is a clash in constructional conventions which both enter into the cognitive modeling of the situation as described. In this case, the convention of genre-specific language use won over the the use where the logic of implicature is preserved. This is important to keep in mind when looking at pragmatics as equivalent to the study of logic.

The importance of convention in these cases reminded of the principle of 'convention over configuration' introduced by the programming framework Ruby on Rails:

"Convention over Configuration" means a developer only needs to specify unconventional aspects of the application. For example, if there's a class Sale in the model, the corresponding table in the database is called sales by default. It is only if one deviates from this convention, such as calling the table "products_sold", that one needs to write code regarding these names.

This is exactly what happened in this case. The use of 'suspect' causes the reader (or rather some readers) to search for information about the implied arrest. When none is forthcoming other avenues of resolving the conflict need to be sought. However, even though the process can be described broadly algorithmically, it is really much fuzzier and parallel and could not be all that easily modeled through a conventional flowchart that would be appropriate for a computer language. But the analogy is striking nevertheless. Particularly, since we could see this RoR convention as an expression of a hypostasis of the underlying pragmatic principles of language.