A few months ago, the first mobile expression of a news concierge materialized in the form of NOD – News On Demand. NOD is an iPhone app that tailors news to the user’s available time and attention by providing three important stories daily, in two sizes, and allowing to find them from a catch up calendar.

It’s about separating signal from noise to a quite extreme extent (wtf, 3 news per day only??!) and I’ve received many questions – at presentations, in meet-ups and conferences – about the selection process of these 3 stories. Why only 3? And why these and not others? But the question that people are really asking me is: define “important”.

So, I tried to explain what I talk about when I talk about “important” news:

Interesting: is the story telling you something insightful, necessary or fascinating about the world we live in today?

Matter: will the story also matter tomorrow? Is this the beginning of something that you may hear from in the next few days (think: a trial start, a cop killing leading to protests)? Is this the conclusion of an event that will make history?

Pressing: is the event very likely to be in conversations with friends or at work today, or in a few days maybe? Then you may want to be caught up on it.

Original: is there an odd and unique angle to an apparently “light” news story? Taking the opportunity of George Clooney’s wedding to learn about the great work of human rights lawyer Amal Alamuddin makes a celebrity story more important.

Relevant: our users send us a lot of signals through their behavior. We try to act on them : for example, our users give a lot of “nods” to stories on climate change, so when Chile is flooded or a typhoon of uninque size hits the Philippines, it seems more relevant than a man past-retiring age saying he’ll retire.

Trending: is the story making headlines in a wide array of outlets, including major publications, aggregators like Google News and social media like Twitter and Facebook? Will our users wonder why everyone’s making a fuss about this?

Accurate: too often, stories are broken and then turn out to be falsely stated or completely trumped up. Fake kidnappings, murder charges that are dropped, people tested for Ebola who make headlines for 2 days cause they’re found to be healthy after all… So I’d rather wait 24 hours. For breaking news and breaking corrections, there are other outlets.

New: is the story about something we didn’t know yet? A lot of “NEWs” is merely an update in a longer story arch or a quote ping-pong (think Hillary’s email-gate, negotiation processes and plane crash theories).

Timely: obviously, all the stories we curate need to be fresh. If we put out an edition every 24 hours, the events have to have been reported on in the same time-frame.

There will be instances where at least one of these criteria may apply to something that doesn’t show up in the daily NOD edition. This is not enough, though: stories need to score, if not all, as many of those criteria as possible. Sometimes, I push the boundaries a bit: I do this on purpose to trigger user feedback and make NOD better (please write when you disagree!)

Of course, this is anything but perfect. Being human, we shouldn’t aim for perfection anyway, but for continuous improvement. So, I want to know: how do you define important news?