Points are a weird and inconsistent unit of measure
buttondown.com
buttondown.com
CSS | | Exact Size | Exact Size
Unit | Name | (Inches) | (Millimeters)
--------------------------------------------------------
cm | Centimeter | 50/127 | 10
mm | Millimeter | 5/127 | 1
Q | Quarter-millimeter | 5/508 | 1/4
in | Inch | 1 | 127/5
pc | Pica | 1/6 | 127/30
pt | Point | 1/72 | 127/360
px | Pixel | 1/96 | 127/480
Digging deeper, the kyu -- or Q for quarter millimeter -- is apparently a foundational distance measurement in Japanese typesetting, which is metric and operates on a millimeter grid.
> the German and Japanese point is 0.250 mm
It's probably the sanest adaptation of the point to the metric system. A traditional point is close to a third of a millimetre, but that's too weird.
Since the Q is close to 3/4 of a traditional point, it's also quite easy to convert from traditional multiple-of-three point sizes: 9 pt -> 12 Q, 12 pt -> 16 Q, etc.
Although it's even easier just to call those 3 mm and 4 mm!
;)
You need to start using SI points that are defined using wavelengths of ground state emissions of a decaying Americium atom.
https://startbigthinksmall.wordpress.com/2010/01/04/points-i...
Mapping story points to time doesn't really work for individual cases because of those different experience levels, it's going to heavily depend on who does the case. Instead, you track story points competed in total for the team for the entire sprint - the different experience levels average out into something consistent, like 30-35 story points per sprint.
"Velocity" is related scrum terminology, and is the mapping of that whole-team measure back to time. A previous team that understood how this worked and stuck to it had those story points per two-week sprints, so we could estimate things months out with reasonable accuracy despite the different skill levels.
I also thought this post was going to be about story points because it's a common complaint from people who don't understand the "different experience levels" part. If everyone on the team reliably took the same amount of time for a given case, then yeah, you could cut it out and just estimate in time. But it's not for that.
In the end, the work takes the time it takes, and nobody knows how long that will be ahead of time. Fiddling around with estimates helps with ranking but not prediction.
Over time the estimates should be trending closer to outcome, as the process improves in breaking down and specifying the details that impact prediction & work, and the statistical gap from previous estimates gets baked into future estimates. The process, capabilities, ability to identify diverging factors, and correction of initial estimates should all be maturing concurrently.
The entire point of using fuzzy numbers is to enable fuzzy yet usable predictions. Similar work in a similar situation, armed with specific statistics and outcome, should be highly predictable at the team and individual level over time.
The past X weeks of point-estimates is what you use to forecast which things fit in the next Y weeks, and you can't have both stability and forecast accuracy. Any attempt to permanently "peg" a point to a certain number of man-hours is going to interfere with that accuracy.
Instead metric system is predictable and easy to work with.
Real question is why US just don't move to metric system?
"Going metric" raises the question of whether we adopt metric measures for our existing standards (such as pipe threads) or actually adopt the ISO sizes. The latter would cause a brief but massive inventory management problem, that nobody's ever willing to put up with, even if there's a long term benefit.
I believe we made a mistake in how we tried to teach the metric system. I learned in first grade: Metric is easy because it's just math. Most people heard "math" and freaked out. Metric was taught as a bunch of conversions and units. Inches were taught as: Here's a ruler, go measure some things.
I remember talking to a machinist, and he said: "I hate the metric system because there's so much math." That was 30+ years ago. Today, machinists just read mm or inches from the same digital readout or CAD program.
My Canadian friends learned metric as: Here's a ruler, go measure some things.
The real advantage of metric is that you only have to do math once to calculate something. A cc is a ml is a gram. A liter is a cubic decimeter is a kg. It's just easy. A deep lake over a few square km? O(1) GT. Understanding orders of magnitude is a useful trait in a democracy.
You hit the nail on the head here though:
> My Canadian friends learned metric as: Here's a ruler, go measure some things.
Like any language, as long as you're translating you're loosing. Post signs in km and report temperature as C and everyone will understand it in less than a decade. A few years after I had a metric thermometer in my car C seemed easy.
It's not like the US failed to think of this. In the 80s they were posting signs in km. But back then there was a real economic cost to conversion for factories and machines. Now that's mostly gone, what remains is cultural resistance.
The ironic thing is that an Imperial pint of water weighs more than a pound.
Okay but what about the off chance you’re measuring something other than water?
But it turns out that water is a pretty good bet most of the time:
- Settled snow is around 0.25
- Dried wood is around 0.5
- Soil is around 1.2
- Rock is around 2.5
Which is pretty good if you want to answer "how much does that truck / ship / mountain / lake weigh?".
Of course there are some anomalies: Tungsten is around 20, but it's not like imperial units help here, and the name literally translates to "heavy rock".
You adopt ISO sizes FFS. They are international standards. You really want to invent a whole new set of incompatible 'standards'?
You think the US is the first to go through this? Australia, Canada, and the UK went metric in the 1970s (we also decimalised our currencies). Yes it was challenging for some adults but mostly pretty easy for kids. People adapted. Industries adapted. Now we hardly think about it except when dealing with Americans or in some historical contexts.
We can still do a better job teaching metric to kids, without needing to tear down every building to replace all the 2-by-4s with "50x100s." But yeah, that means dealing with the fact we don't have everything following the standards and our pipe threads, screws, etc. will always be different to yours.
That’s true of everywhere in the world at the time they made the switch (give or take a decade). Why is that a problem unique to America?
You can make a better case that we were fools to not stay the course in the 1970s than a case that we should try it today. Even the 70s seem more like the very tail end of a window. 1776 would have been a great time to do it!
Why does the absolute number matter? Every trades truck/stockpile will need to stock double for some time, not some absolute value increase.
The long-term gain is being able to sell your stuff to the rest of the world, and being able to import stuff from the rest of the world without paying a Weird Format Tax.
Would you rather manufacture stuff for 8 billion people, or for 340 million?
Cutting metric or imperial threads in a pipe fitting is a programming code change in a CNC machine, and maybe using a different cutting tool. Easily done for an order that's going to be exported.
So I don't think manufacturing is a big concern, and not the reason we've stayed with old standards in many cases.
There would need to be like a minimum 50-year transition where everything will be worse (keep both of everything in stock because both old and new need maintenance) and we'll probably have more confusion and mistakes over what units were being used during that half-century.
I love metric. I think it's awesome. But I'm not sure what anyone expects anymore. We attempted the same half-assed conversion Canada did in the 1970s when Jimmy Carter was President and people were pretty sane. We did only a little bit worse than they did[1] though. It boggles the mind to imagine a US populace as determinedly political and polarized as they are now adopting even a slightly inconvenient lifestyle change just because the government said so. Therefore, "you guys should just adopt metric" seems less than productive.
[1] https://www.reddit.com/r/Metric/comments/hmyt6a/how_to_measu...
Pretty common to talk about measurements of 1/2, 1/4, 1/8, 1/16 of an inch and find those graduated on a ruler. Or 1/2, 1/3, 1/4, 1/8 of a cup for liquid measures, etc.
But then machinists generally work in thousandth or ten-thousandths of an inch.
And most of the kitchen stuff is a chicken-and-egg problem: the US used 1/2 cup because that's what it is used to, the rest of the world has recipes calling for 50g of flour. If the US was used to weight-based measurements everyone would have a kitchen scale with 0.1g precision lying around, instead of a bunch of measuring cups.
These incessant arguments of "why is someone doing something different than what I'm used to so stupid" are funny if not tiring. Why not ask why are there so many different spoken languages in the world instead of just speaking like me? We could go into if Rust is better than Go, or why Romulans are better than Klingons. The problem is that nobody wants to understand the differences and just want to rag on the person opposing their views. Yawn
Why are you conflating speed and precision? A cup-ish measure would be 200g and no one is measuring that to .05% accuracy.
On the flip side, good luck getting .1g precision out of a measuring cup if you need it.
The point you're not willing to accept is that there's no dying need to be that precise and using "cup-ish" measures is good enough and works just fine.
Precision is orthogonal to the unit.
Everything is standardized on IEEE floating point. ;-)
It's a headache to maintain collections of parts and tools such as taps and dies for both standards.
The biggest shift is simply the obsolescence of old stuff, and emergence of new stuff. And industries have adopted the practice of reducing the overall variety of parts needed. I work in the development of industrial measurement equipment, and where a design might once have had 30 different sizes of fasteners, now it's 5, all metric. Designs rarely need nuts and spacers any more. Washers are integrated into the screws. No more "philips" or flat head screws. And so forth.
What is the modern approach where nuts/bolts and spacers would have been used?
> No more "philips" or flat head screws.
Torx? Rivets? Something else?
At where I work, we use hex head (trying not to say Allen). I see lots more Torx in products as well.
Miles are great. The typical highway speed limit is about a mile a minute. You can easily lower bound how long it will take to get somewhere if you know how far it is in miles.
In cooking, I often need to halve quantities in recipes, hence pounds and ounces. Watching cooking channels give metric quantities is absolutely baffling to me. You see things like 175 mL. That is 2 sigfigs too many.
I do woodworking and framing and approach is similar. Measure out to 6 feet first, then move out 3 inches more. It’s iterative refinement. To measure lengths I always do a few bisections like 3 feet, 2 inches, and 3/4 plus a sixteenth. I can remember a sequence of 3 or 4 integers for about a minute, long enough to transfer the measurement. Give me something like 135mm, and I’ll forget in a few seconds.
Don’t take up baking then, where the difference between 175 mLs of water and 200 mLs of water can be the difference between unworkable dough and the perfect pie crust.
1 1/3 decimeter, perhaps?
To me asking why we don't have a single measuring standard is similiar to asking why we don't all agree on a single language. Sometimes it would be easier, sometimes it wouldn't, but in the end it doesn't matter all that much.
The metric system is poorly suited for font sizes. Most designs require a series of sizes within a small range: a typical book or poster might use 9pt for footnotes, 12pt for main text, 16pt for subtitles, and 24pt for titles.
Aesthetically speaking the most attractive ratios of sizes are small ratios like 3:2 and 4:3. Using points it is very easy to construct an attractive range of font sizes like my example above. It is difficult to imagine how this would look in a metric system that's not a mess.
Shouldn't the real smarties be using 10-hour days using metric time? 100 minutes per hour, 100 seconds per minute.
We could use the birth date of that jewish prophet, except we'd still be off by a few years. Oh well, in a few centuries no one will care, and we'll just use Unix Epoch.
If Europeans are so smart, why didn't they commit to metric time which is soon much easier to understand?
Europe should just have one time zone on a one day clocks divided into decidays and centidays.
24-hour time is terrible. An analog clock doesn't have that written on it...
Because we live in a land of liberty!
The maga people are ready to die on this hill.
They've been trying for a long time, but apparently it's not an easy task.
You can read more here: https://en.wikipedia.org/wiki/Metrication_in_the_United_Stat...
So, how and when did points come into play? ...
Well, ok. I stop procrastinating for now (i hope). I hate my brain.
The mention of
is kind of interesting --- hadn't heard of it before --- may need to revisit the "ProportionBar" tool which I made ages ago....
The distinction ends up being important if you need compatibility with some document format, or with common typesetting expectations. But if there weren't a concern of surprising people with certain expectations of font-picking widgets, I'd argue that the better choice would be millimeters.
4mm is a great default font size, and going up by one integer mm at a time is a reasonable step size (it's just under 3pt).
So disappointed that this document, as much as it obsesses over obscure physical quantities no one cares about, makes no mention of THE FUCK.
1 fuck is equal to the amount of concern you have about something below which you cannot achieve without having no concern at all, as which giving "zero fucks" is defined. "Absolute zero fucks" would be the formal terminology.
For preliminary purposes, we can assume 1 fuck = 1 shit = 1 damn, but must account for the possible existence of a big-point-vs-printers-point style situation. Also they could be drastically different, like if 1 shit given about global warming would be equivalent to 299_792_458 fucks or something like that.
I have very little knowledge about the *real* machinations behind the standardization of measures (a tinfoil conspiracy kook would call it an Agenda 21, or 21 Agendas One, but I'm not going there), I want this to be discussed.