Posts Tagged 'data mining'

‘AI’ performance not what it seems

As I’ve written about before, ‘AI’ tends to be misused to refer to almost any kind of data analytics or derived tool — but let’s, for the time being, go along with this definition.

When you look at the performance of these tools and systems, it’s often quite poor, but I claim we’re getting fooled by our own cognitive biases into thinking that it’s much better than it is.

Here are some examples:

  • Netflix’s recommendations for any individual user seem to overlap 90% with the ‘What’s trending’ and ‘What’s new’ categories. In other words, Netflix is recommending to you more or less what it’s recommending to everyone else. Other recommendation systems don’t do much better (see my earlier post on ‘The Sound of Music Problem’ for part of the explanation).
  • Google search results are quite good at returning, in the first few links, something relevant to the search query, but we don’t ever get to see what was missed and might have been much more relevant.
  • Google News produces what, at first glance, appear to be quite reasonable summaries of recent relevant news, but when you use it for a while you start to see how shallow its selection algorithm is — putting stale stories front and centre, and occasionally producing real howlers, weird stories from some tiny venue treated as if they were breaking and critical news.
  • Self driving cars that perform well, but fail completely when they see certain patches on the road surface. Similarly, facial recognition systems that fail when the human is wearing a t-shirt with a particular patch.

The commonality between these examples, and many others, is that the assessment from use is, necessarily, one-sided — we get to see only the successes and not the failures. In other words (HT Donald Rumsfeld), we don’t see the unknown unknowns. As a result, we don’t really know how well these ‘AI’ systems really do, and whether it’s actually safe to deploy them.

Some systems are ‘best efforts’ (Google News) and that’s fair enough.

But many of these systems are beginning to be used in consequential ways and, for that, real testing and real public test results are needed. And not just true positives, but false positives and false negatives as well. There are two main flashpoints where this matters: (1) systems that are starting to do away with the human in the loop (self driving cars, 737 Maxs); and (2) systems where humans are likely to say or think ‘The computer (or worse, the AI) can’t be wrong’; and these are starting to include policing and security tools. Consider, for example, China’s social credit system. The fact that it gives low scores to some identified ‘trouble makers’ does not imply that everyone who gets a low score is a trouble¬† maker — but this false implication lies behind this and almost all discussion of ‘AI’ systems.

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New data on human trafficking

The UN’s International Organisation for Migration has just released a large tranche of data about migration patterns, and a slick visualization interface:

https://www.ctdatacollaborative.org/

Some of the results are quite counter-intuitive. Worth a look.

And so it begins

Stories out today that Google is now able to connect the purchasing habits of anyone it has a model for (i.e. almost everybody who’s ever been online) with Google’s own data on online activity.

For example, this story:

http://www.smh.com.au/technology/technology-news/google-now-knows-when-its-users-go-to-the-store-and-buy-stuff-20170523-gwbnza.html

Google says that this enables them to draw the line between the ads that users have been shown, and the products that they buy. There’s a discrepancy in this story because Google also claim that they don’t get the list of products purchased using a credit card, but only the total amount. So a big hmmmmm.

(And if I were Google, I’d be concerned that there isn’t much of a link! Consumers might be less resentful if Google did indeed serve ads for things they wanted to buy, but everyone I’ve ever heard talk about online ads says the same thing: the ads either have nothing to do with their interests, or they are ads for things that they just bought.)

But connecting users to purchases (rather than ads to purchases) is the critical step to building a model of how much users are willing to pay — and this is the real risk of multinational data collection and analytics (as I’ve discussed in earlier posts).

“But I don’t have anything to hide”

This is the common response of many ordinary people when the discussion of (especially) government surveillance programs comes up. And they’re right, up to a point. In a perfect world, innocent people have nothing to fear from government.

The bigger problem, in fact, comes from the data collected and the models built by multinational businesses. Everyone has something to hide from them: the bottom line prices we are willing to pay.

We have not yet quite reached the world of differential pricing. We’ve become accustomed to the idea that the person sitting next to us on a plane may have paid (much) less for the identical travel experience, but we haven’t quite become reconciled to the idea that an online retailer might be charging us more for the same product than they charge other people, let alone that the chocolate bar at the corner store might be more expensive for us. If anything, we’re inclined to think that an organisation that has lots of data about us and has built a detailed model of us might give us a better price.

But it doesn’t require too much prescience to see that this isn’t always going to be the case. The seller’s slogan has always been “all the market can bear”.

Any commercial organization, under the name of customer relationship management, is building a model of your predicted net future value. Their actions towards you are driven by how large this is. Any benefits and discounts you get now are based on the expectation that, over the long haul, they will reap the converse benefits and more. It’s inherently an adversarial relationship.

Now think about the impact of data collection and modelling, especially with the realization that everything collected is there for ever. There’s no possibility of an economic fresh start, no bankruptcy of models that will wipe the slate clean and let you start again.

Negotiation relies on the property that each party holds back their actual bottom line. In a world where your bottom line is probably better known to the entity you’re negotiating with than it is to you, can you ever win? Or even win-win? Now tell me that you have nothing to hide.

[And, in the ongoing discussion of post-Snowden government surveillance, there’s still this enormous blind spot about the fact that multinational businesses collect electronic communication, content and metadata; location; every action on portable devices and some laptops; complete browsing and search histories; and audio around any of these devices. And they’re processing it all extremely hard.]

Refining “Data Science”

Regular readers will know that I have been thinking about the constellation of ideas that are getting a lot of play in universities and the research community around words like “data science”, and ‘big data”,¬† and especially the intersection of these ideas with the other constellation of “data mining”, “knowledge discovery” and “machine learning”.

I’ve argued that inductive model discovery (which I think is the core of all of these ideas) is a new way of doing science that is rapidly replacing the conventional Enlightenment or Popperian view of science. This is happening especially quickly in fields that struggled to apply the conventional scientific method, especially in medicine, the social “sciences”, business schools, and in the humanities.

Attending the International Conference on Computational Science meeting made me realise, however, that computational science is a part of this story as well.

Here’s how I see the connections between these three epistemologies:

  1. Conventional science. Understand systems via controlled experiments: setting up configurations that differ in only a few managed ways and seeing whether those differences correspond to different system behaviours. If they do, construct an “explanation”; if they don’t, it’s back to the drawing board.
  2. Computational science. Understand systems by building simulations of them and tweaking the simulations to see if the differences are those that are expected from the tweaks. (Simulations increase the range of systems that can be investigated when either the tweaks can’t be done on the real system, or when the system is hypothesised to be emergent from some simpler pieces.)
  3. Data science. Understand systems by looking at the different configurations that naturally occur and seeing how these correspond to different system behaviors. When they do, construct an “explanation”.

In other words, conventional science pokes the system being investigated in careful ways and sees how it reacts; computational science creates a replica of the system and pokes that; and data science looks at the system being poked and tries to match the reactions to the poking.

Underlying these differences in approach is also, of course, differences in validation: how one tells if an explanation is sufficient. The first two both start from a hypothesis and use statistical machinery to decide whether the hypothesis is supported sufficiently strongly. The difference is that the computational science has more flexibility to set up controlled experiments and so, all things considered, can get stronger evidence. (But there is always the larger question of whether the simulation actually reproduces the system of interest — critical, but often ignored, and with huge risks of “unknown unknowns”.) Data science, in contrast, validates its models of the system being studied by approaches such as the use of a test set, a component of the system that was not used to build the model, but which should behave as the original system did. It is also buttressed by the ability to generate multiple models and so compare among them.

Data science is advancing on two fronts: first, the flexibility it provides to conventional science not to have to construct carefully balanced controlled experiments; second, and much more significantly, the opportunity it creates for making scientific progress in the social sciences and humanities, replacing “qualitative” by “quantitative” in unprecedented ways.

Why Data Science?

Data Science has become a hot topic lately. As usual, there’s not a lot of agreement about what data science actually is. I was on a panel last week, and someone asked afterwards what the difference was between data mining, which we’ve been doing for 15 years, and data science.

It’s a good question. Data science is a new way of framing the scientific enterprise in which a priori hypothesis creation is replaced by inductive modelling; and this is exactly what data mining/knowledge discovery is about (as I’ve been telling my students for a decade).

What’s changed, perhaps, is that scientists in many different areas have realised the existence and potential of this approach, and are commandeering it for their own.

I’ve included the slides from a recent talk I gave on this subject (at the University of Technology Sydney).

And once again let me emphasise that the social sciences and humanities did not really have access to the Enlightenment model of doing science (because they couldn’t do controlled experiments), but they certainly do to the new model. So expect a huge development in data social science and data humanities as soon as research students with the required computational skills move into academia in quantity.

Why data science (ppt slides)


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