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I’m an Agilist, a former software engineer, a gamer, an improviser, a podcaster emeritus, and a wine lover. Learn more.

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Paul Tevis

Entries in things i've read (31)


In The Beginner's Mind There Are Many Possibilities...

I sent out this paper to my team at work this week. I already believed in a some of the ideas it, but the data and (even-to-me counterintuitive) results that it presents surprised me. I’m now very curious to see if we can replicate them, and at the very least, it’s got me thinking about we decide who works on what in a very different way.


Fitness: 100 Ups (Minor) + 100 Hundred Pushups, Week 1, Day 2 (6-8-6-6-12)

More Than the Sum of Its Parts

Over the last two years, I’ve repeated run into the concept of “systems thinking.” From context clues, I was able to cobble together a rudimentary understanding, but I never had an formal grounding it in. A month or so ago, I heard several people on Twitter mention Thinking in Systems: A Primer, so I downloaded the Kindle sample and took a look. That was quickly followed by buying the book and devouring it.

From a structural perspective, the critical features of systems are stocks (the amounts of something you have, like temperature or population or electrical charge), flows (the ways that stocks change), and feedback loops (which change flows based on the quantity of a stock). Think about the temperature system in your house. Heat flows in from the furnace, which raises the temperature of the room. Heat flows out of the room to the outside, which lowers the temperature. So you’ve got a single stock with one inflow and one outflow. The rate at which heat comes in to the room is controlled by your thermostat, which compares the current temperature to the desired temperature. The rate at which it flows out is control by the laws of thermodynamics, which tries to equalize the inside and outside temperatures. So in this system you have two competing feedback loops, and which one will dominate depends on initial conditions and the specific values of certain variables.

There are a couple of nuances here, of course. Feedback loops come in two varieties: balancing and reinforcing. Balancing feedback loops try to drive a stocks to a specific value (like the two loops in the temperature example), while reinforcing loops cause a stock to increase exponentially over time (like compound interest). But as was reading the first couple of chapters, I thought, “These concepts are pretty intuitive.”

Then I hit the car dealership inventory example, where delays in the balancing feedback loop cause oscillations in the dealer’s inventory. That piqued my curiosity. On the next page I saw how reducing some of these delays — which seems like it should make the problem better — actually increases the amplitude of the oscillations. And that’s when I knew had to keep reading.

My initial assessment was correct in this respect: Most of these concepts are easy to understand, at least in static analysis. The two-chapter overview of the components of systems and some well-chosen examples from the “systems zoo” gave me a reasonable grasp on the sorts of things I might encounter. Systems, of course, are dynamic things. One of my two favorite sections of the book is on “sources of system surprises,” an explanation of why we so often fail to apprehend the dynamic behavior of systems. These include the multitude of non-linear relationships in systems, the problem of bounded rationality, and that the limits on a system exist in layers around it. Systems are less simple than they look, and that’s were we get in trouble.

Trouble is the underlying theme of my other favorite part of the book, on “systems traps and opportunities.” This explains problems like arms races, the tragedy of the commons, even drug addiction, from a systems perspective and offers ways out. This was the most resonant section for me, because it caused me to start seeing systems everywhere. As I listened to an NPR story about the economic impacts of Alabama’s new immigration enforcement law, I started drawing stocks, flows, and feedback loops in my head. When I read about solutions to the “success to the successful” trap, I thought, “Oh, this is how Power Grid prevents the runaway leader problem by giving the last place player the most advantageous position.”

This is all useful information, but the key is that it is presented in one of the most human voices I’ve read. The book was published from a manuscript Donella Meadows had been working on when she passed away unexpectedly. Her decades of experience and understanding come through in way that is remarkably humble. As such, while the book is technical, it’s surprisingly applicable and astonishingly approachable. Which makes it the kind of book I would like to write someday.


Fitness: 3 miles

Ghost Story

Spoilers for Ghost Story and earlier books in the Dresden Files series follow

So I finished Ghost Story last night. Short version: It’s a Wonderful Life without enough Clarence.

Over the course of the book, Harry learns what effects — good and bad — his choices have had on the world at large and the people he cares about. Harry sees how much his presence meant to keeping Chicago safe now that he’s gone. He also learns first-hand about the consequences of his actions at Chichén Itzá, from the power vacuum the fall of the Red Court has created to the emotional toll its taken on Molly and others. Because he spends much of the book unable to interact with anyone, there’s a lot of observing and self-reflection.

The problem is that instead of being able to act on those realizations, or even talk with someone about them, Harry just ruminates on them. He’s introspective in large blocks of text, which often falls a bit short of the mark. During the early parts of the book he has Sir Stuart to interact with, but once he become effectively lobotomized by the Grey Ghost’s attack, Harry loses that outlet as well. Later on he’s able to talk with Bob about some of these things, but that opportunity is sadly brief. Harry’s struggle here is almost purely internal and expository, and as such, I’m less interested in it.

There’s also a lot flashbacks in this book. Given the conceit that ghosts in the Dresdenverse are creatures of memory, the amount of text given over to Harry’s recollections of his life makes sense. That said, I wish some of those memories ended up being more relevant to the plot at hand. We got ton of new details about Justin DuMourne and He Who Walks Behind… that didn’t end up mattering materially in this book. At the same, I had a hard time remembering who the Corpsetaker was and exactly what she did in Dead Beat, so I feel like the words given over to dredging up the past could have allocated a bit more effectively.

I did love the gonzo, dreamscape-type sequences Harry’s condition made possible. From the Saving Private Ryan assault on the Nevernever to the bridge of the U.S.S. Enterprise inside Molly’s head, there were some great — and very Dresden — situations that I had fun visualizing. Ghost Story also had the best scenes between Harry and Leanansidhe so far; I felt for the first time like I really understood their relationship. I do have to say: From the moment I read the end of Changes, I was convinced Kincaid shot Harry, but never saw coming that Harry hired him to do so and then got Molly to wipe his memory of it. And the final scene — with Harry, Mab, and Demonreach — was awesome. I loved the last quarter of the book; I was less enamored of the first seventy-five percent.

This is very much a transitional book, which makes sense given what happened to Harry in Changes. It feels fairly different from the earlier books, and the events at the end of the book seem to indicate that at least the next one will go back to form. That makes me happy. I’m looking forward to seeing what sort of trouble the Mad Wizard Dresden gets himself into — and out of — as the Winter Knight.


Fitness: Rest day
Sun, Moon, and Stars: 388 words, 467 seven-day average, 278 average, 47000 total, 1000 to go for the week; 9-day streak

"The dean of the 'hard-boiled' school of detective fiction"

With The Glass Key my tour of Dashiell Hammett’s novels comes to a close.

The Glass Key is in some ways Hammett’s Plunkitt of Tammany Hall. The central character, Ned Beaumont, is a gambler and political fixer for Paul Madvig, the “boss” of an unnamed East Coast city around 1930. He’s not a private detective, like the Continental Op or Sam Spade, the protagonists of Hammett’s three earlier novels. He’s tougher than either of them, and once he gets his teeth into something, he’s a dog who doesn’t let go.

As in any good hard-boiled story, the map is not the territory. The Glass Key takes place against a backdrop of a political machine — the upcoming election is the central plot device of this story, as the titular bird is in The Maltese Falcon — but ultimately this is story about the end of a friendship. This is said to be Hammett’s favorite novel, and I suspect it was the most personal (especially considering Beaumont’s similarities to Hammett himself).

I read Hammett’s novels slightly out of order, starting with his last, The Thin Man, before circling around to the beginning with Red Harvest and going chronologically from there. All five of them were published between 1929 and 1934, which is remarkable considering the impact they had on the genre. His protagonists form a curious constellation of characters. The Op of Red Harvest has more in common with Beaumont in The Glass Key than he does with the Op of The Dain Curse. Sam Spade clearly grows out of the archetype established in The Dain Curse and would transform into Raymond Chandler’s Philip Marlowe.1 And The Thin Man’s Nick Charles thumbs his nose at this whole hard-boiled thing.

Thanks for the ride, Dash.

1 It occurs to me now that Chandler’s The Big Sleep and Farewell, My Lovely follow in the footsteps of The Dain Curse, while The High Window is the successor to The Maltese Falcon.


Fitness: Rest day
Sun, Moon, and Stars: 407 words, 387 seven-day average, 274 average, 41420 total, 420 past the goal for the week; 18-day streak

Designing Good Meetings

How do we avoid bad meetings? By knowing what the goal of the meeting is, designing an agenda to meet it, and communicating both to the group.

The Facilitator’s Guide to Participatory Decision-Making identifies seven different types of meeting goals:

  • Sharing Information
  • Obtaining Input
  • Advancing the Thinking
  • Making Decisions
  • Improving Communication
  • Building Capacity
  • Building Community

Each of these have distinct patterns of interaction and information flow. They require different types of involvement from the participants. The same kinds of activities will not work equally well for them.

And speaking of activities, it’s important to remember that open discussion — the most common meeting activity — is only one of the many possible ways to structure group work. Among the alternatives are:

  • Presentations and reports
  • Structured go-arounds
  • Individual writing
  • Listing ideas
  • Working in small groups

Setting the stage for a good meeting requires picking the right activities for the meeting goal.

Finally, once these details have been figured out, the participants need to know about them. If someone comes into an Advancing the Thinking meeting expecting to be on the receiving end of Sharing Information, he or she isn’t going to be well-equipped to contribute. And if someone thinks that the group will be Making Decisions when instead they’re going to be Building Community, the potential for unnecessary frustration is high.

I’ve seen how these techniques have improved some of the meetings I’ve facilitated. The challenge for me now to is to practice these skills consistently and teach them to the team so that we can make all of the meetings we’re in better.


Fitness: Two hours of tossing concrete around in the garden
Sun, Moon, and Stars: 303 words, 375 seven-day average, 269 average, 38709 total, 709 words past the goal for the week; 11-day streak