Original post: http://bearlamp.com.au/adding-and-removing-complexity-from-models/

I had a really interesting conversation with a guy about modelling information.  what I did when talking to him is in one case insist that his model be made more simple because adding more variation in the model was unhelpful, and then in another case in the same conversation, insist his model be made more complicated to account for the available information that didn't fit his model.

On reflection I realised that I had applied two opposing forces to models of information and could only vaguely explain why.  With that in mind I decided to work out what was going on.  The following is obvious, but that's why I am writing it out, so that no one else has to do the obvious thing.

Case where a model should be simplified

This all comes down to what you are measuring or describing.  If you are trying to describe something rather general, like "what impact do number of beach-goers have on the pollution at the beach?", it's probably not important what gender, age, race, time spent at the beach or socioeconomic status the beach goers are.  (With the exception of maybe socioeconomic status of the surrounding geopolitical territory), what is important is maybe two pieces of information: 

1. A measure of the number of beach goers
2. A measure of the pollution

That's it.  This would be a case for reducing the survey of beach goers down to a counter of beach goers and a daily photo of the remaining state of the beach at the end of the day (which could be compared to other similar photos).  Or even just - 3 photos, one at 9am (start), one at 1pm (peak) and one at 5pm (end).  This model needs no more moving parts.  The day you want to start using historic information to decide how many beach cleaners you want to employ, you can do that from the limited but effective data you have gathered.

Case where a model should have more moving parts added to it.

Let's continue the same example.  You have 3 photos of each day, but sometimes the 1pm photo is deserted.  Nearly no one is at the beach, and you wonder why.  It's also messing with your predictions because there is still a bit of rubbish at 5pm even though very few people were at the beach.  The model no longer explains the state of the world.  The map is wrong.  But that's okay.  We can fix it by adding more information.  You notice that most days the model is good, so there might be something going on for the other days which needs a + k factor to the equation (+k is something added in chemistry, in algebra it's sometimes called a +c as in y=mx+b+c, and physics +x, but generally adding a variable to an equation is common to all science fields).  Some new variable.

Let's say that being omniscient to our own made up examples we know that the cause is the weather.  On stormy windy rainy days - no one goes to the beach, but some rubbish washes up.  Does this match the data? almost perfectly.  Does this help explain the map?  Yes.  Is it necessary?  That depends on what you are doing with the information.  Maybe it's significant enough in this scenario that it is necessary.

Second example

The example that came up in conversation was his own internal model that there is fundamentally something different between someone who does exercise, and someone who Doesn't exercise.  I challenged this model for having too much complexity.  I argue that the model of - there is a hidden and secret moving part between does/doesn't exercise, is a model that doesn't describe the world better than a model without that moving part.  

The model does something else (and found its way into existence for this reason).  If you find yourself on one side of the model (i.e. the "I don't exercise") then you can protect yourself from attributing the failure to exercise to your own inability to do it by declaring that there is a hidden and secret moving part that prevents me from being in the other observable group.  This preserves your non-changing and let's you get away with it for a longer time.  I know this model because that is what I did.  I held this model very strongly.  And then I went out and searched for the hidden and secret moving part that I could change in order to move myself into the other group.  There was no hidden and secret moving part.  Or if there was I couldn't find it.  However, I did manage to stop holding the model that there was some hidden and secret moving part, and instead just start exercising more.

In figuring out if this model is real or a made up model to protect your own brain from being critical of itself, start to think of what the world would look like if it were true.  If there was some difference between people who do exercise and people who do not - we might see people clustered in observable groups and never be able to change between them (This is not true because we regularly see people publishing their weight loss journeys, we also regularly see people getting fatter and unhealthier, suggesting that travel in either direction is entirely possible and happens all the time).  If there were something describable it would be as obvious as different species, in fact - thinking evolutionarily - if such a thing existed, it's likely that it would have significantly shaped the state of the world already to be completely different...  Given that we can't know for sure, this might not be a very strong argument.  

If you got this far - as I did and wondered, so why can't I be in the other group - I have news for you.  You can.

• Does this pattern of models with too many moving parts sound familiar to another model you have seen in action?  
• Is there a model that you use that could do with more moving parts?

Meta: this took an hour to write.  If I were to spend more time on it, it would probably be to tighten up the examples and maybe provide more examples.  I am not sure that such time would be useful to you and am interested in if you think it will be useful.

Original post: http://bearlamp.com.au/wicked-problems/

Nothing is a wicked problem.

When I started researching problems and problem solving and solutions and meta-solving processes I stumbled across a wicked problem. This is from Wikipedia:

Rittel and Webber's 1973 formulation of wicked problems in social policy planning specified ten characteristics:[3][4]

1. There is no definitive formulation of a wicked problem.
2. Wicked problems have no stopping rule.
3. Solutions to wicked problems are not true-or-false, but good or bad.
4. There is no immediate and no ultimate test of a solution to a wicked problem.
5. Every solution to a wicked problem is a "one-shot operation"; because there is no opportunity to learn by trial and error, every attempt counts significantly.
6. Wicked problems do not have an enumerable (or an exhaustively describable) set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan.
7. Every wicked problem is essentially unique.
8. Every wicked problem can be considered to be a symptom of another problem.
9. The existence of a discrepancy representing a wicked problem can be explained in numerous ways. The choice of explanation determines the nature of the problem's resolution.
10. The social planner has no right to be wrong (i.e., planners are liable for the consequences of the actions they generate).

Conklin later generalized the concept of problem wickedness to areas other than planning and policy.  The defining characteristics are:

1. The problem is not understood until after the formulation of a solution.
2. Wicked problems have no stopping rule.
3. Solutions to wicked problems are not right or wrong.
4. Every wicked problem is essentially novel and unique.
5. Every solution to a wicked problem is a 'one shot operation.'
6. Wicked problems have no given alternative solutions.

Defeating a wicked problem

It took me a while to realise what a wicked problem was.  It is evil.  It's a challenge.  It's a one-shot task that you don't really understand until you are attempting to solve it, and then you influence it by trying to solve it.  It's wicked.  And then I started paying attention to everything around me.  And suddenly being a social human was a wicked problem.  Every new interaction is not like the last ones, as soon as you enter the interaction it's too late; and then you only have one shot.  Any action towards the problem adds more complexity to the problem.

Then I looked to time management.  Time management is a wicked problem.  You start out knowing nothing.  It takes time to work out what takes time.  And by the time you think you have a system in place you are already burning more time.  Just catching up on a bad system is failing at the wicked problem.

Then I looked to cooking.  No two ingredients are the same.  Even if you are cooking a thing for the 100th time, the factors of the day, the humidity, temperature, it's going to be different.  You can't know what's going to happen.

Then I looked at politics.  And that's what wicked problems were invented around, social problems where trying to solve the problem changes the problem.  And nothing makes it easier.

Then I took my man-with-a-hammer syndrome and I whacked myself on the head with it.

Okay so not everything is a hammer-nail wicked problem.  Even wicked problems are not a wicked problem.  There are problems out there that are really wicked problems, but it would be rare that you find one.

There is a trick to solving a wicked problem.  The trick is to work out how it's not a wicked problem.  Sure if it's wicked by design so be it.  But real problems in the real world are only pretending to be wicked problems.

1. The problem is not understood until after the formulation of a solution.
   

Yeah, okay.  So you don't really get the problem.  That's cool.  You have done problems before.  And done problems like this before too.  The worst thing to do in the case of being presented with a problem which is not understood is to never attempt it.  If you don't understand - it's time to quantify what you do understand and quantify what you don't understand. After that it's time to look at how much uncertainty you can get away with and how to solve that.  If in doubt refer to the book How to measure anything.

2. Wicked problems have no stopping rule.

Real wicked problems don't have a stopping rule but real world problems do.  Or you can give them one anyway.  How many years is enough years of life.  "I don't know I will decide when I get there".  How much money is enough money? "I will first earn my next 10 million dollarydoos and then decide what to do next".  Yes.  A wicked problem has no stopping rule.  But that's not the real world.  In the real world even a fake stopping rule is good enough for your purposes.

3. Solutions to wicked problems are not right or wrong.

Okay.  Maybe a tricky one.  Lots of things are not right or wrong.  "should I earn to give, or should I bring around FAI sooner?".  Who knows?  Right now people are arguing about it but we don't really know.  If you are making decisions based on right or wrong you probably want to do the right thing.  We know already that if you can't decide that makes all options equally good and irrelevant what you choose.  If you can make one more right than the other - do that.  It's probably not a real wicked problem.  "How should I format this word document" is not a right or wrong, but it's also irrelevant.

4.  Every wicked problem is essentially novel and unique.

Yes.  If you are facing a truly novel and unique problem there is nothing I can say that can help you.  But if you are not, there are many options.  You can:

• build a model scenario and test solutions
• look for existing examples of similar problems and find similar solutions
• try to break the problem into smaller known parts
• consider doing nothing about the problem and see if it solves itself

IF a problem is truly unique, then you really have no reason to fear the unknown because it was not possible to be prepared.  If it's not unique - be prepared (we are all always being prepared for problems all the time)

5. Every solution to a wicked problem is a 'one shot operation.'

Yea, these are hard.  Maybe some of the solutions to 4 will help.  Build models, try search or create similar scenarios (why do trolley problems exist other than to test one-shot problems with pre-thought-out examples).  You only get one shot to launch a nuclear missile the first time (and we are very glad that we didn't ignite the atmosphere that time).  Now days we have computer modelling.  We have prediction markets, we have Bayes.  We can know what we don't know.  And we can make it significantly less dangerous to launch into space - risking the lives of astronauts when we do.

6.  Wicked problems have no given alternative solutions.

Yes.  Wicked problems don't, but real world problems could, and often do.  Find those solutions, or the degrees of freedom in your problem.  Search and try to confirm possible options, find friend scenarios, and use everything you have.

Nothing is a wicked problem.

Meta: This took 1 hour to write and has been on my mind for months.  Coming soon: Defining what is a problem