February 19, 2018

How to Understand Ockham’s Razor

“More things should not be used than are necessary.” Common translation of text attributed to William of Ockham, 14th century English theologian.

“Everything should be made as simple as possible, but not simpler.” Often attributed to Albert Einstein.

Ockham’s Razor is a mental tool for reasoning about scientific theories. It’s often oversimplified to something like “The simplest theory is usually the best.” The idea is that if you have two theories, and you don’t know which is correct, you can do pretty well by just choosing the simpler one.

But is this really a good idea?

I will admit up front that I don’t have the credentials to say anything new or surprising about Ockham’s Razor. I’m not a logician, philosopher, or historian, and I gave up my scientist aspirations a few years ago. I’m not even sure how to spell “Ockham” (“Occam” is one alternative). But I know a little bit about scientific inference, and I’ve given this subject some thought. So here we go.

First, let’s dispose of the idea that the simplest theory is usually the best. While a popular interpretation, this is neither a good translation of any text attributed to William of Ockham, nor a useful rule of thumb in practice. Yes, simplicity is a desirable property in scientific theories. But if you have to rely on comparing absolute levels of simplicity between two dissimilar theories, then you’re in very bad inferential shape. It’s useless as a rule of thumb, because there’s no objective absolute measure of simplicity. Just about any two theories can be described in a way to make the one you like seem simpler. It’s probably only a hair better than comparing two sports teams on the basis of how intimidating their mascots are.

So what is Ockham’s Razor good for? Actually, quite a bit. There’s a simple interpretation that is valid and quite useful, even if it’s not such a great sound bite.

Suppose you have a theory, composed of various postulates, that is sufficient to explain (predict) some data. As an explanation for that data, you should prefer that theory by itself to the combination of that theory and any additional postulate. Or in plainer terms: don’t glom extra stuff onto your theory that doesn’t help explain the data.

Here’s an illustration. Suppose we’re interested in why stuff falls down. One theory might be gravitational forces. If I tell you that my theory of gravity is a good explanation of things falling, you might examine the evidence and determine that it does an awfully good job of explaining the data. If, however, I tell you that my theory also postulates that Francis Ford Coppola is the finest director in the history of cinema, we might have a good use for the razor. Use it to strip away the parts of my theory that are superfluous, or (to echo one translation) “beyond necessity.” In this case, you would be right to look me squarely in the eye and ask, “Are you sure the bit about Coppola is really essential to explaining falling objects?” And after you establish that gravity alone does just a good job as gravity + Coppola, you would be entitled to do some slicing. It may very well be true that Coppola is a great director. But this fact probably doesn’t have a place in anyone’s theory of falling objects.

The razor is really not for comparing disparate theories. It’s most useful when you have a single theory, and you want to pare its formulation down to the essentials. It can be tricky. Maybe you have some genuinely puzzling data, and a complex, well-articulated model that does a surprisingly nice job of explaining the data. It will be tempting to regard the data as support for the entire model. Ockham’s razor admonishes you to keep only the parts that are doing the explanatory work, and discard the rest. If your model is a giant arithmetic hairball, it may take some work to figure out which features are just window dressing and which are essential. But you are obligated to do this work for any facet you want to claim is supported by data.

If you are somehow in the unfortunate position of having two theories to consider, with absolutely nothing but parsimony to go on, then although it’s very sad, you really don’t have any business choosing. Choosing the simpler one may be slightly better than flipping a coin, but only slightly. In fact, it’s unlikely you’ll even have an objective way of deciding which is simpler. You need more to go on before cutting anything with a razor.

So there you have it. I don’t know if this is exactly what William of Ockham had in mind 700 years ago, but it’s easily described and intuitively sensible. This is the kind of interpretation that tends to show up in writings geared towards scientists and philosophers. So that’s how I like to think about it, and I think you should too.

And for the record, although I do think Coppola has produced some deeply wonderful films, I don’t think it makes sense to pick a single finest director in the history of cinema.

January 1, 2018

How to Fix “The Last Jedi” (WITH SPOILERS)

WARNING: BASICALLY ALL SPOILERS

I really enjoyed The Last Jedi. Even though I’m way too old for this kind of thing, the original Star Wars came out when I was ten, and I can’t completely escape my childhood. So I’ve been looking forward to the latest installment for two years, and I’ve now seen it twice with my family.

Although I found a lot to enjoy, I also had some reservations. Maybe it was just the high standard set by The Force Awakens, but I felt like a handful of fixable flaws kept The Last Jedi from meeting the same high standard. So like any truly dedicated fan should, I thought I’d take a stab at the futile exercise of trying to rewrite the movie a bit.

But first, some ado – disclaimers, ground rules, and whatnot:
  • There was a lot about The Last Jedi that I really did like, and I’ll save space at the bottom for a list of those. But they’re just less fun to write about.
  • I’ve seen the movie just twice, and read a few plot summaries to fill in the gaps. There are certainly things I missed. I’ll likely revise this when I’ve seen it again.
  • I’m suggesting ways to improve the movie they made, not propose a meaningfully different one. That would be a much bigger (and even more pointless) exercise. And I do acknowledge that it’s much easier to pick out flaws in something that exists than it is to actually make something new. I’m trying to do the easy part.
  • All my knowledge of Star Wars comes from the nine feature films, a handful of articles, and the aforementioned synopses. I haven’t read any of the books or watched any of the animated series, and I don’t visit fan sites.
And some more ado – a tiny cheat sheet in case you’re as bad at keeping track of names as I am:
  • Admiral Holdo – the purple-haired interim Resistance leader, played by Laura Dern
  • Lieutenant Connix – the quiet-ish officer who hangs out with the Resistance leadership, played by Billie Lourd (Carrie Fisher’s daughter)
  • The Supremacy – The First Order’s lead Star Destroyer, the one Holdo rams
  • DJ – the traitorous codebreaker, played by Benicio del Toro
  • Canto Bight – The Casino Planet
  • Crait – The Ice Planet with the red salt
  • TFA – The Force Awakens
  • TLJ – The Last Jedi
What are the problems I felt needed to be fixed? I’m going to focus on plot elements that felt like distractions from, rather than integral parts of, the story.

First, Admiral Holdo. Everything involving Holdo feels like a weakly motivated distraction. She appears from nowhere when an attack leaves the Resistance without leadership. She picks a fight with Poe for no good reason -- despite his demotion, he’s as much a Resistance leader as she is, all the more so because of the attack that left Holdo in charge, and there’s no good reason for her to refuse to explain her plan to him. But her character goes nowhere. In the end, she cheerfully agrees to be left behind to die after a brief, upbeat conversation with Leia.

There’s a lot I could unpack, but let me just pick out one element, the decision to sacrifice one of the top two Resistance leaders. Does that decision make sense? It’s not clear in the movie if either Leia or Holdo knows that Holdo is going to ram the Supremacy. If neither knows (which I think is the most natural reading), then it’s just a nonsensical decision. There’s zero reason to leave her behind to “pilot” the ship, and in fact we see that, until she gets the bright idea to ram the Supremacy at light speed, she’s just standing around, gazing out the window. If Holdo did think of her plan in advance, then by the same reasoning, Leia would only let her go if she also knew the plan. And if that’s the case, then it’s asking a lot of the audience to believe that sacrificing one of the top Resistance leaders was the best plan they could think of. They can’t control the ship remotely, or program it in advance? Maybe find a less irreplaceable volunteer? Did they even talk about this? If we really have to keep the suicide run, then the film owes it to the audience to at least make an effort to make it seem like they gave it some real thought, and it was actually unavoidable.

If I had to speculate, I’d guess that the scriptwriters were forced to write Dern into the script, and didn’t have the time to work out all the kinks. Or maybe it’s just that they had a vision of a grand dramatic sacrifice, but couldn’t bring themselves to sacrifice any of the existing characters. Either way, everything involving Holdo feels like a distraction from the story.

Relatedly, the conflict between Holdo and Poe is silly. It’s great that they establish so early in the movie that Poe’s swashbuckling can be far too costly. And it’s fine if there’s some friction between them. But Holdo’s behavior feels cartoonish and out of place. And her plan, revealed later, really is ridiculous. Poe’s mutiny also feels flat, as though even the actors couldn’t make sense of the action. And there’s just no good reason for Leia to zap Poe with a stun gun. I get it that the script needed a bit of conflict to spice up the Resistance scenes. But these interactions feel contrived at best, and there are much better ways (and places) to heighten the tension.

The plan to turn off the tracker for a few seconds, by sending Finn and Rose to recruit Maz’s codebreaker friend, is silly and convoluted, and again feels like a weakly motivated distraction. The result is that the entire trip to Canto Bight seems only very tenuously connected to the rest of the movie, even before you find out that it ultimately leads nowhere. I’ve read suggestions that those scenes should have been cut. But I think the opposite makes more sense – the movie does need a critical and action-packed side mission to help get the Resistance out of their jam, and I’m willing to believe that sending Rose and Finn makes sense. But it needs to be more clearly (and plausibly) connected to a good plan to escape the First Order.

After Finn and Rose return and are betrayed by DJ, they’re dragged out in front of Phasma, Hux, and about a thousand stormtroopers, for a combination execution / awards ceremony. The scene serves no purpose beyond getting Phasma a few more cheesy lines as she draws out the execution in truly Bondian (or perhaps Batmanian) fashion. And then, the place blows up, leaving all of the principals unscathed while apparently killing off just about every last stormtrooper. Hux vanishes, BB-8 gets his big moment, Finn finishes off Phasma with very little trouble, and the good guys all escape on a shuttle. What is the point of all this? We really don’t need any more closure on the Finn-Phasma relationship, and we’re left with the realization that the entire plotline with Finn and Rose hasn’t furthered the story one bit.

There are smaller things I could pick on, but in general, TLJ feels like it has a few too many moving parts, and part of that is having too many characters that seem to have very loosely connected storylines. I feel like the role of Holdo may have been as large as it was more because she was played by a well known actor than because that’s how the story worked best. To a lesser extent the same goes for DJ (whose storyline could still continue into Episode IX). I’d rather see better development of existing characters, and in existing storylines. Why is Maz only in about 30 seconds of the movie? Lieutenant Connix did have an expanded role, but it could have been even more so. I’m okay with Rose, because I feel like she serves the story, rather than the other way around (also, Kelly Marie Tran is just great).

So here’s how I’d do it differently.

Suppose they have the slam-the-transport-into-the-Supremacy plan from the outset, and that they’re pretty sure it will take care of the tracker. No human needs to be sacrificed to make this happen, and we did learn in TFA that it’s possible to get through a shield when you’re going at light speed. But there’s a huge obstacle: they know that it does them no good if they don’t then have a way of getting away from the other ships. And the shuttles don’t do light speed. So for the larger part of the movie, they’re in a desperate standoff – keeping out of range of the Supremacy, but not able to get away, and increasingly worried about fuel.

To break the standoff, they need help from their allies. So they send Rose, Finn, and Poe (RFP) to get help from Maz, who is on Canto Bight, and can help them steal a big ship. As it happens, Canto Bight is not just where the wealthy profiteers like to gamble, it’s also where some of the manufacturing takes place. It’s no stretch at all to imagine that Maz is stirring up trouble there. The bits about the enslavement of animals and children can still fit if needed.

While there, they get into a bit of trouble and are lucky to escape with the ship (it makes much more sense that trouble would come from talking to Maz and from stealing a ship than due to a parking violation). We can still work Benicio del Toro into this plotline. Maybe he’s the guy with questionable loyalties who can pilot the ship they’re stealing (although it would take some care to avoid turning him into Han Solo 2). There are opportunities for plotting here that I’m going to gloss over – the scenes on Canto Bight can be as long or as short as needed.

At the same time the Resistance dispatches RFP, they call for Rey. Rey’s return plays out much as it does already. The timing is delicate, although the timing never makes much sense in these movies. But it could add some nice tension if the Resistance gang thinks they might have to destroy the Supremacy with Rey still on it. Again, this can be made to work in much the way it already does.

The A plan was to ram the Supremacy with one ship and escape in the other. But because the RFP mission took longer than expected, the transport ran out of fuel and the Resistance had to jump on the shuttles. When the First Order gets distracted picking off shuttles, they fire the first transport at it. By the time RFP return with the ship, what’s left of the Resistance is on Crait, and RFP manage to join them just ahead of the First Order.

At some point, the new ship is damaged or destroyed. So the end of the movie plays out as it already does, with the last of the Resistance escaping on the Millenium Falcon.

What does this do for us:
  • Drops most of the major ridiculous plot elements, including the Holdo suicide, the Holdo-Poe nonsense, the staged execution scene, the convoluted story about the tracker and the codebreaker, Leia shooting Poe with a stun gun, etc. And some that just don’t contribute anything, like Phasma.
  • Adds tension and conflict to the middle of the movie by dropping aimless squabbling and adding (a) a much clearer but still very desperate Resistance plan that we can focus on for the duration, and (b) well motivated action on Canto Bight that’s integral to the plot.
  • Simplifies the Resistance scenes in the middle of the movie. Basically, they’re just keeping out of range, hoping RFP get back in time, keeping a nervous eye on the fuel gauge. This doesn’t have to occupy nearly as much screen time as the Holdo scenes.
  • More Maz.
  • Creates options for shortening the movie, or (my preference) keeping it at its current length by reworking the Canto Bight scenes effectively.
Some additional thoughts:
  • Within this framework, there’s a nice way of extending the Poe-as-cowboy tension if Poe actually suggests the ramming plan. We’ve just been told that he’s a cowboy, and now both the characters and the audience have to think extra hard about whether or not this sacrifice (of the ship, not a person) is worth it.
  • It may not be essential to send Poe along with Finn and Rose, but I think it makes much more logical sense than sending Finn and Rose alone, and gets him into some more believable action. Also, they need a pilot. It doesn’t need to take anything away from Rose’s role, and I think it would be a lot of fun to see RFP as a team.
  • It would be fun to interrupt Maz in the process of fomenting a revolution. This would dovetail nicely with what’s already in the movie, and will probably segue nicely into Episode IX. There’s also the option of giving Maz a role in finding a good landing spot for the Resistance, which would also create a stronger bridge to the next movie.
  • There are tons of options for DJ. He could be dropped entirely, or he could be Maz’s go-to guy for finding a ship to steal. Conceivably there could be an excuse to bring him back, which would put him in a position to betray the Resistance going into Episode IX. But it’s not essential.
  • I know Laura Dern is a big name, but the more I’ve thought about it, the more convinced I am that dropping Holdo entirely is the right thing to do. An existing character would have to take over when Leia is incapacitated. I like the idea of having an expanded role for Lieutenant Connix, which would better emphasize how the Resistance was really decapitated to the point of having someone very young and previously invisible suddenly thrust into a leadership role.
  • One more shot of Kylo Ren at the end of the movie would have been nice. Just a glimpse of his conflicted face.
Some problems with my version:
  • The trip to Canto Bight still ultimately amounts to nothing, since the Resistance takes such heavy losses that they’re all able to fit on the Millenium Falcon. Having a tiny group escape on the Falcon is a good ending for the movie, that emphasizes how dire the situation is, so we don’t want to lose that. I’m open to suggestions for what else RFP could have accomplished on Canto Bight. It's possible the answer is just that the First Order manages to blow up the first ship before it can ram the Supremacy, and the new ship, originally meant to be their escape vehicle, is the one that does the ramming. Either way is really fine, since it’s at least clear why they’re doing what they’re doing, and what’s at stake.
  • It seems crazy to drop Laura Dern. But I think it's the right thing for the movie. The scene where someone has to assume command just works much better if it’s Connix (who’s been quiet, but visible) than if it’s a new character we haven’t seen before. If we’re dead set on keeping Holdo, reducing her role to something simpler would be preferable.
  • Phasma has little or no role. Although I love Gwendoline Christie, I think that’s fine too. Through two movies, she’s done little more than stand around and look shiny. We shouldn’t have to work so hard to find things for her to do.
  • I feel like Finn going AWOL still doesn’t really fit well. But if cut, we’d need another excuse to get Rose into the movie.
Finally, let me mention one more thing that irked me, before I move on to the list of things I liked.

I realize that everyone has a different level of tolerance for humor in an otherwise serious (well, non-comedic) movie. For reference, I thought the humor in “The Force Awakens” was done perfectly – it always felt organic, and never seemed to interrupt the flow of the movie. To my ear, the humor in The Last Jedi frequently crossed the line into silliness, zingers in the spirit of old Arnold Schwarzenegger movies. More like having a wisecracking friend sitting next to you in the theater than like having humor in the movie's actual dialogue. Not always, but often enough that I noticed. I feel like this is another indication that the script was a bit rushed.

And now, the parts I loved. I have less to say about these, because I know you loved them too.

Rey is special because she's special, not because of whose kid she is. The dialogue through which this was revealed was just terrific. This was a mature authorial decision that shows that the screenwriters behind this movie really do know a thing or two about storytelling (and I really hope they don’t undo it).

Kelly Marie Tran. She was a great addition to the cast.

Yoda. I was worried when Yoda appeared. But the scenes worked very well in service of the interesting twist that Luke, far from being an all-knowing Jedi guru, is flawed and troubled and, maybe even more so than Rey, needs guidance himself. Yoda sums up one of the movie’s most central themes in as few words as possible when he tells Luke, “We are what they grow beyond.” Kylo Ren echoes the sentiment with a more sinister cast when he later says, “The Empire, your parents, the Resistance, the Sith, the Jedi... let the past die. Kill it, if you have to. That's the only way to become what you are meant to be.”

The interactions between Rey and Ren. These scenes have great tension, and each one feels like a cliffhanger.

The throne room scene. Although TLJ didn’t have any single moments quite as spine-tinglingly exciting as when Rey out-forced Ren to a lightsaber in TFA, there were several moments in this scene that came close.

Ren’s internal conflict. He seems if anything even more torn than in TFA. It’s evident in his face, in his reluctance to kill his mother, and in his ambiguous actions and dialogue. Where in TFA he often just seemed childish, his character felt much more nuanced in TLJ. He isn’t sure who he is, but we know by the end of TLJ that he’s finally going to have to decide.

Glimpses of interesting themes and plot elements that are likely to be central in Episode IX and beyond. The next generation of Jedi is out there, whether they’re called Jedi or not. Mercenaries (not the charming Han Solo kind) and profiteering arms dealers are a new layer of bad guys to think about.

The delicate cinematography of the ramming sequence, accompanied by cutting out the sound, was beautiful.

Confronting the cowboy mythology. The opening battle asks us explicitly to consider the fact that Poe's recklessness can be counter-productive. Even though that storyline got tangled up and then lost in the Holdo jumble, it was a nice counterpoint to what we’ve seen in previous movies. The Resistance has very serious problems that you can’t simply solve by hopping in an x-wing and blowing stuff up.

Mark Hamill has had his rough spots as an actor, but he wasn’t bad here. Although the Luke-Rey bits on the island may have fallen a little flat, it wasn’t an issue with the acting.

And lastly, I thought some of the new ships were cool looking, even though I'm skeptical of the value of bombers that "drop" bombs in space.


On balance, The Last Jedi had a mix of really interesting things to think about and bits that made me groan. I wrote this article because most of the latter seemed fixable. But my inner child is just as excited as ever to see what happens in Episode IX. I wish I could write the script, but since I can’t, I’ll just have to wait.

May 8, 2016

How Not to find Good Books

They say not to judge a book by its cover. But if we’re literally talking about books, what are the better options? This is a question that has tortured me forever, and for which I have no good answer. I’ve tried many options, yet somehow I still end up spending my very limited reading time on far too many books I regret reading. I recognize that many of these books do appeal to many people. But shouldn’t there be some signal I can use to work out if a book’s liable to appeal to me specifically?

Maybe so, but I haven’t found it yet. Here are a few straw men that are easy to knock down.

Read the first few pages, or skim a bit. I do like this option, because it’s easy. But some of the best books I’ve ever read start very, very slow. Many books have good hooks but go nowhere. Skimming has never told me anything much more helpful than whether or not the book is more exposition or dialogue.

Professional reviewers? I’ve made this mistake far too many times. Well known book reviewers in widely read publications tend to overflow with praise for terrible books. I’ve come to the conclusion that it can’t possibly have anything to do with what’s between the covers.

Online reviews? Online reviews are notoriously unreliable, although if a book has enough reviews, you can sometimes read between the lines a bit to work out which kinds of people felt which way about it. Still, it’s led me astray too many times.

Friends? I have few if any friends who admit to reading books, only one I occasionally discuss books with, and none who can produce well-informed advice about what I might like. I enjoy reading as a solitary activity, not a social one, so this isn’t likely to change, although it’s always remotely possible some new friend I haven’t met yet will turn out to have similar reading preferences.

Recommendation systems (e.g., what Amazon thinks you’ll like, based on your previous ratings)? Notwithstanding all the hand-waving I see about this, recommendation systems for books (and movies) are still terrible. When they recommend books (or movies) that they don’t know I’ve read or not, they’re mostly things I didn’t like.

Actually, yes, go by the cover. Blurbs are mostly useless, but the synopsis tells you something, and the cover itself probably has some clues about who the publisher thought the book would appeal to. Not a great option, but is it really any worse than the rest?

Books by authors you’ve enjoyed in the past. Sure, this can work out well. But you wouldn’t be in this predicament if you hadn’t already more or less exhausted that supply, or if you weren’t looking for find something new.

Am I missing something? I don’t have a good solution, other than doing the best I can with these noisy bits of information, and being prepared to drop them frequently.

The situation is possibly a little better for movies. I feel like with movies, there are far more cues about what kind of movie you’re getting yourself into. Maybe because movies are more stereotyped somehow? Because it’s much easier to get a sense of a movie from a few clips? Or possibly just because the relative popularity of movies means there are many more options for getting opinions of all kinds.