
Tacit knowledge is more important than deliberate practice - shadowsun7
https://commoncog.com/blog/tacit-knowledge-is-a-real-thing/
======
travisjungroth
I figured out something very similar in flight school. When I did my
instrument rating, I realized my instructor, Sean, wasn’t perfect. No pilot
is. But, I believed he could pass an instrument check ride. I could not.

I decided that rather than figure out if everything he did was the best way or
“worked for me”, I would just do my best Sean impression. I still had the
opportunity to get even better by learning from other instructors or coming up
with my own ideas. That could wait until after I got my rating.

He actually noticed. At the beginning of an early lesson he showed me his
check routine during taxi. He flowed through all of the instruments and
controls. The next flight, I did my best impression. It wasn’t perfect, but it
was close. When I was done he told me no student had ever gone through the
whole thing the next flight. Most don’t even try. Even the better students
just grab a few things and end up with a routine close to his by the end of
training.

It all ended up working. I passed my check ride with just about the legal
minimum amount of training time.

Writing this all out and talking about what a great student I was feels pretty
egotistical. Ironically, that’s the opposite of what this method is about.
Just copy the closest person next to you who is better than you. They don’t
even have to be that great. Then, find someone better, and copy them. Save
breaking new ground for later in your journey.

~~~
corporateslave5
You never become exceptional this way. And if you run into situations you’ve
never seen before, it’s harder to react competently. With coding, if you only
ever use a style you copy, then everything looks like it could be solved in
that way. This works and may help you up the corporate ladder. But it will
never produce massively positive results

~~~
ssivark
That may or may not be the case, but note that there are many (most?) domains
where the positive payoff is bounded, but the negative payoff is not. This
method seems particularly useful for those scenarios -- if you have "adequate"
performers to copy from.

~~~
travisjungroth
Instrument flying is actually a great example of this. There are no instrument
flying competitions. Well, I guess there’s one every flight. First place, you
make it there. Second place, you diverted. Third place, you crash and probably
die.

------
Wistar
Wow. I have never really given this subject much thought.

In thinking about it, it seems an important part of teaching tacit knowledge
is to establish, or cause, conditions that encourage the learning — the
experiencing — of the specific things you want to teach.

Thinking back, I realize my own example of successfully teaching tacit
knowledge was when I taught my son the first part of how to drive a car with a
manual transmission: getting the car moving without killing the engine or
burning up the clutch. I took him to a large level area, a huge parking lot,
and told him he can do whatever he wants as long as he never touches the
throttle. It only took a couple of hours before he had mastered knowing
exactly how to modulate the clutch "bite" so that he could get the car moving
without stalling, even with the engine at idle. That the car was an older
Toyota Corolla with very little torque only helped him better master the
finesse required to release the clutch exactly as needed.

We then moved on to modulating the throttle and clutch together, shifting,
starting out on hills and all that but, by then, he already knew how to deal
with the dark art of the clutch.

~~~
larrik
I do something similar with guitar. I can teach chords and notes, but I can't
teach you how to hold the strings down properly in the first place. "Go play
with this until you make the notes every time without a buzzing sound"
basically.

~~~
sojournerc
I wish I could gift my callouses to beginners. It takes some time to build
solid finger tips that can fret consistently at different angles, at the most
discouraging part of the learning curve.

------
lifeisstillgood
>>> He gave me a long explanation about software engineering principles. I
waved him away and asked how he did it in five seconds. He said “Well, it just
felt right. Ok, let’s go to lunch, you can fix it afterwards.”

Yes. I do a lot of coding on feel, and just today was explaining why something
could be done one of two ways but one was better. It took about 30 seconds for
my concious brain to work out why it was, even though my unconcious brain knew
it straight away.

Weird. Try getting that in an expert system (which might be why they never
took off).

And of course try getting that into a CDN without equivalent of twenty years
practise.

How do we label good and bad business decisions? Every day?

(side note: actually this is a serious thing I am hoping to work on next year.
I think the next big stage of human computer work is computer coaching or
feedback on our behaviour. Easy things like our spending habits but heading
towards coaching on interpersonal actions - could we for example film a great
manager day in day out and identify their activities - and then get them to
label the actions - who they spoke to who they encourage why they took that
negotiating stance. Do it enough times and you have a real training base.)

~~~
allenu
So much of coding and seeing good and bad design patterns is unconscious
pattern matching and unconscious heuristics. I have the same experience of
trying to put into words why one design pattern is better than another and it
definitely is frustrating because from experience I do have a tacit "feel"
about why something is wrong but to convey that to someone else is a
challenge.

~~~
andruby
Would we call that "intuition"?

~~~
lifeisstillgood
yeah, but we want to analyse this - is my intuition same as most other 20 year
experienced coders? Is it good / correct intuition? is it transferable - can I
see same patterns in a different language ? how far away from one language do
we go before it breaks down (ie php -> python > java > clojure.)

------
xrd
So many amazing thoughts in this article that apply to the world of software
engineering.

If tacit knowledge is as important as the author makes out, then hiring "young
guns" is always going to have a cost over hiring people that have done it
before. As an older developer, that's interesting to me. A contrary point,
however, is that maybe all businesses are new domains of exploration, so you
might as well pay the cheapest person to develop your domain specific tacit
knowledge.

If tacit knowledge is not something you can get by reading, then training and
mentoring is much better (dare I say vital!) than documenting it all in a
wiki, or just making sure everything is done asynchronously in a well written
pull request.

If tacit knowledge is that important, then getting it is a privilege. If you
are in a position where you can be paid to develop those skills and don't just
have to read up in the evenings after your kids have gone to bed. Many people
don't have that privilege but the software industry prides itself partially on
the idea that you just have to self teach yourself; if you aren't doing that,
you won't be successful in your job. Tacit knowledge is not that.

~~~
joe_the_user
_If tacit knowledge is not something you can get by reading, then training and
mentoring is much better (dare I say vital!) than documenting it all in a
wiki, or just making sure everything is done asynchronously in a well written
pull request._

This is a weird thing to argue. Productivity could be something like [system-
knowledge] X [tacit-knowledge-of-programming] so just tacit knowledge wouldn't
get a team maximum productivity.

Altogether, it seems like what's tacit in programming or tacit in any complex
domain is "how to integrate different complex and sometimes contradictory
things". It's important but hardly important in a "you can discard everything
else, this is the magic" sort of way.

~~~
xrd
I agree with you.

But, tell me if you think I'm wrong: I'm arguing that most software companies
have a mentality like you describe: "you can discard everything else, this is
the magic" about wikis, PRs (so they generally ignore mentoring and training,
or at least don't want it on their employees schedules).

I think you are saying I'm saying that I think that mentoring and training
allow you to throw the rest away. I'm not saying that.

------
omarhaneef
It seems we rediscover Gilbert Ryle's knowing-how vs knowing-that distinction
every few years.

[https://en.wikipedia.org/wiki/Gilbert_Ryle](https://en.wikipedia.org/wiki/Gilbert_Ryle)
or if you are so inclined

[https://plato.stanford.edu/entries/knowledge-
how/](https://plato.stanford.edu/entries/knowledge-how/)

Note: if you have a computer and it can be "told" once and forever remember
it, then converting know-that into know-how by teaching it 100s of if-then
rules was, at one point, considered a worthy research program.

~~~
sandspar
It's funny that several thousand words that laboriously reinvent the wheel
about tacit knowledge could be summed up in a handful of words of declarative
knowledge.

------
bwestergard
If, in a mood of theoretical reflection, you make articulation in written or
spoken language the criterion for "knowledge", it comes as a disappointment to
think of all of the cases where we speak of someone knowing something (e.g.
how to ride a bike) even though they are unable to train someone to do so
entirely verbally (e.g. by written instruction, or over the phone).

But adding the epicycles of "tacit knowledge" and "rules followed
unconsciously" clarifies nothing. The mistake was in the overly restrictive
definition of "knowledge".

I've surveyed some of the critiques of the "tacit knowledge" concept in this
article:

[https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8267598](https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8267598)

~~~
shadowsun7
Are you familiar with the Recognition Primed Decision Making Model, or the
field of Naturalistic Decision Making? NDM is a field of research that focuses
on taking expert intuition (which I refer to as tacit knowledge in this
piece), extracting it out of the heads of professionals and then creating
training methods to enable less skilled operators to learn these tacit skills
on their own. The methods are primarily associated with and deployed in the
military.

I think the most famous paper from this tradition is Gary Klein and Daniel
Kahneman's A Failure to Disagree, which lays out the conditions necessary for
expert intuition:
[https://www.fs.usda.gov/rmrs/sites/default/files/Kahneman200...](https://www.fs.usda.gov/rmrs/sites/default/files/Kahneman2009_ConditionsforIntuitiveExpertise_AFailureToDisagree.pdf)

(The two are intellectual rivals, but they put aside their differences to
write this piece, over a period of about 6 years, IIRC.)

If you want to get at a definitional debate about the computing applications,
that is fine by me. If you want to argue about the philosophical problems with
Polanyi's formulation, that is also cool. But understand that I don't
particularly care for either debate. I am interested in instrumental outcomes.
The discovery of tacit knowledge and the methods found in NDM have been
incredibly useful to me in the pursuit of skill acquisition. This was mostly
what I was getting at in the post.

~~~
qznc
I just realized that Klein and Kahneman conditions are a good argument for
apprenticeships in programming.

One condition is that the you get quick feedback about your decisions. For
example, if a surgeon makes a mistake then blood splatters. In programming, if
you make a syntax error the compiler immediately complains. However, a design
mistake might only bite you months or years later. That is a big obstacle for
developing an intuition. However, if an apprentice programmer makes a design
mistake. His master can give quick feedback.

I can imagine that the lack of such feedback not only results in slower
learning. It might mean the non-apprentice programmer is unable to ever
acquire an intuition for design no matter how many years of experience.

~~~
itsArtur
> I can imagine that the lack of such feedback not only results in slower
> learning. It might mean the non-apprentice programmer is unable to ever
> acquire an intuition for design no matter how many years of experience.

Yes! This is also worsened by the fact that changing jobs frequently is so
common. This makes me appreciate my first job, where good design was a
priority, so much more.

------
dragonwriter
Misleading title: the thesis is more accurately “Tacit knowledge is why NDM
methods are more useful than deliberate practice”.

It also doesn't actually do much to explain that thesis, dismissing delivered
practice with the quick an for shallowly-addressed claim that it only works in
field with established pedagogy, which may be the case, but most of the fields
that it dismisses deliberate practice for on this basis have established
pedagogy (with, sure, some pedagogical controversies, but that's true if the
field that it acknowledges have the requisite established pedagogy for
deliberate practice, too, so it's not at all clear what, if anything, the
distinction being drawn is), and doesn't actually do much to establish that
NDM methods are particularly useful for developing tacit knowledge. Basically,
the piece is an extended discussion of the idea of tacit knowledge, with the
whole primary argument, to which most of the piece is only tangentially
relevant, rushed through at the end as if it were an afterthought.

~~~
shadowsun7
> dismissing delivered practice with the quick an for shallowly-addressed
> claim that it only works in field with established pedagogy

This is the _actual definition of deliberate practice_. As in, Ericsson
explicitly says deliberate practice CAN ONLY exist in domains with a long
tradition of pedagogical development.

Go and read the original papers by Ericsson. Or the Cambridge Handbook of
Expertise and Expert Performance. Or his popular science book Peak.

One of the nice things about writing a blog is that you get to bring an
audience along on a journey of discovery. In this case, you don't actually
have to go very far — the blog has done the work for you. This is a 5k word-
ish summary of Peak: [https://commoncog.com/blog/peak-book-
summary/](https://commoncog.com/blog/peak-book-summary/) ... and this is a 5k
word summary of all the criticisms arrayed against deliberate practice, also
linked from the piece above. [https://commoncog.com/blog/the-problems-with-
deliberate-prac...](https://commoncog.com/blog/the-problems-with-deliberate-
practice/)

If you want to read about NDM techniques — surprise, surprise! It turns out
that the techniques are described in about 10k words over at
[https://commoncog.com/blog/putting-mental-models-to-
practice...](https://commoncog.com/blog/putting-mental-models-to-practice/)
and [https://commoncog.com/blog/putting-mental-models-to-
practice...](https://commoncog.com/blog/putting-mental-models-to-practice-
part-5-skill-extraction/)

And those posts are _also_ linked from the piece.

(Edited to remove snark).

~~~
mcshaner1
I think there is room for nuance here. True deliberate practice is easiest to
apply in those domains, but there are some lessons from Ericsson's work that
can be applied using the NDM framework. I think the point that people miss
often is that it is _deliberate_ practice, not just practice. While we may not
be able to practice like a potential chess grand master, we can deliberately
challenge ourselves and look to learn from our mistakes. If you squint hard
enough, some of what Klein writes about in "The Power of Intuition" seem like
attempts to deliberately practice something in a field without that long
tradition of pedagogical development (or fields that don't train for tacit
knowledge). His paper with Peter Fadde, "Deliberate Performance" also talks
about this. That said, you sometimes don't learn the right lessons, and if the
situation changes too dramatically, all your tacit knowledge might work
against you.

One tangent comment to go with this: One of Klein's occasional coauthors,
Robert Hoffman, co-wrote a book on expert weather forecasters that I really
liked. Weather is hard to predict, but one thing they found that what the best
forecasters did was to look at the data before looking at what the computer
models predicted. Once they had an idea of what they thought the weather might
look like, they compared with the model. This kept their skills sharp and
ensured that they continued to learn.

~~~
shadowsun7
In Peak, Ericsson seems to finally settle on one definition, which was what I
used in the end. He calls what you just describe "not being able to
deliberately practice like a grandmaster" a completely different thing —
purposeful practice.

There's a whole chapter in Peak where he tries to talk about what to do if you
are in a field with badly developed pedagogical methods. It's basically a
badly written copy of The Power of Intuition (Klein). I was incredibly
dissatisfied with it, because I was mostly interested in putting DP to
practice, and his recommendations were far from practicable. I wish he had
just referred to Hoffman or Klein, both of them practitioners in NDM, and
therefore both more familiar with attempts to design training programs for
fields where no pedagogical rigour exist.

I know you're inclined to give Ericsson a pass, and pass things off as
deliberate practice even when his definition clearly excludes said thing. But
my view is that we should call a spade a spade and use the exact definitions
the man used. If he thought it was good enough for his popular audience, it
should be good enough for me.

~~~
mcshaner1
That makes sense, a couple of years ago there was a lot of misleading
interpretations going around, precise definitions help clear things up. I read
Peak a while back, and I must’ve forgot that distinction.

I found the Klein book you mentioned more useful than Ericsson’s as well, that
Fadde/Klein paper I mentioned was also pretty helpful. I need to reread both,
and put them into practice more than I have. I read too much, and I don’t get
the tacit knowledge that comes from experience...

Another good book is Surpassing Ourselves by Bereiter and Scardamalia. They
studied how students developed writing skill. Their definition of expertise is
a bit different than Ericsson’s, but I think it is more useful.

~~~
shadowsun7
Thanks for the recommendations! Adding to my toread.

------
scott_s
Teaching college students how to program my first year of grad school, I
realized that it's not possible to _make_ someone understand something. In a
real sense, I could not _teach_ them to program. Learning how to program is
learning a new way of thinking, and there was no way I could force them to
start thinking in this way. I was more trying to guide them to have many
personal epiphanies - through a combination of socratic method style questions
and giving them specific actions to try with the hope it would improve their
mental model.

~~~
superhuzza
Exactly my experience slowly learning to code as an adult. My partner
sometimes explains a programming concept to me that just won't sink in.

After some practice and time, I can feel my thinking rearranging itself around
the concept until it's second nature. Personally it's a feeling I enjoy, part
of the reason I like taking up new hobbies all the time.

------
TopHand
Tacit knowledge is what I've always thought of as "intuitive feel". As you
grow in experience in a field, you start getting this feel for what will work
and what won't work. This can be a great advantage, or a great disavantage. I
had occasion to work with a fairly bright scientist. He said the reason that
most great discoveries were made by relatively young people is because they
hadn't developed these prejudices yet, so were unaware that it wasn't suppose
to work this way.

------
aardvarks
Nice article! I guess it's obvious in retrospect, but I hadn't known of all
the systematized study devoted to this topic. I'm happy to learn about it
because I've found myself thinking about effective teaching and learning
pretty often (I'm an academic), and what to do about "the stuff where, when
you try to explain it concretely to someone else, your explanation doesn't
really make sense unless the other person already knows what you're talking
about".

In subjects I've tried to learn and teach, my experience is that talking to
someone with a lot of such knowledge really only gives you an idea of the sub-
topics and considerations you should try to understand better on your own. It
is helpful in narrowing down what you should prioritize and maybe giving you a
useful point of view to organize your thoughts from, but that doesn't save you
from doing the thinking and understanding for yourself.

I agree that emulation helps somewhat by forcing you to make choices that are
reasonable even if, as a beginner, you lack the knowledge to choose wisely
yourself. But if the ultimate goal is to come up with new ideas using the
knowledge, I think there's such a thing as too much emulation. You don't want
to become a carbon copy of your mentor either.

I agree that deliberate practice and acquiring tacit knowledge are not the
same thing. To me, deliberate practice is about repeating a certain activity
-- one that you typically _can_ describe in words to someone who doesn't
already know it -- enough times that it's available to you as a tool, eg
playing scales as a musician, times tables in elementary school math. Tacit
knowledge has more to do with how you decide to apply those skills to best
effect.

But my experience has been that they have kind of a symbiotic relationship. If
you didn't have some tacit knowledge to begin with, you wouldn't know what to
practice, or when you had practiced enough to be good. At the same time, it
may not be possible to acquire enough tacit knowledge to become an expert if
you don't have an immediate command of certain skills developed through
deliberate practice. I.e. there's feedback -- more tacit knowledge should make
your deliberate practice more effective, and better skills make it easier for
you to acquire tacit knowledge.

------
woodandsteel
The reason tacit knowledge exists and is essential is because the brain is
immensely complex, and most of what it does is outside consciousness.

To take just one well-studied example, in vision photons hit visual receptors
in the retina, and then go through the optic nerve which is a complex computer
that analyses the signals in stages, like picking out points, then lines, then
shapes, and so on, and then it is sent to several different visual areas of
the brain, each of which pulls out different features, like motion, colors, 3d
shapes, faces, and emotional expressions, and then finally it arrives in
consciousness. Something similar is true for every other sensation, and how
they are integrated to give us our perception and understanding of the world.

As a consequence, children from birth learn all sorts of things without
explicit instruction and often even much focal thought, include the great
majority of the rules of language itself.

All of this is subjectively experienced as a sort of feel or intuition. It is
described by philosophers such as Michael Polanyi and various
phenomenologists. I studied with one of them, Eugene Gendlin, who developed a
method called experiential focusing for helping people make use of their tacit
knowledge (he called it felt meaning). You might want to take a look at his
book Focusing.

One more point. The idea that all knowledge can be clearly explicated is an
example of the denial of human finitudes that is common in much of Western
philosophy, but that are affirmed by other schools Western philosophy, such as
pragmatism, existential-phenomenology, and post-Wittgensteinian analytic
philosophy.

------
hailwren
This is interesting. Wittgenstein argues that this idea of 'tacit knowledge'
has no meaning. What the article describes is practice.

'My point is that their explanations would not lead me to the same ability
that they had.' is a very Wittgensteinian thing to say. See i.e. the parable
of the wayward pupil in the Investigations on what role understanding/practice
even play in the context of a statement like 'would not lead me to the same
ability that they had'

'But the more I pushed, the more exceptions and caveats and potential gotchas
I unearthed.' W argues that this is a result of our concept of what it means
to understand. Can you name an idea where this doesn't hold? W uses a great
example of your knowledge of the Natural Numbers. Just because you hadn't
thought of the number 10324 beforehand, does that mean your knowledge didn't
encompass it? Before you attempt to foist the problem onto mathematical logic
(it doesn't work, but the answers become longer than an HN comment) consider
your concept of the color 'red'. What shape is it? Did you a prior have in
your mind the shape of red? Is there a color that I could show you which you
might consider red and someone else would not?

The core problem is this idea that 'explanations' in the source are implicitly
able to be fully specified or that any knowledge exists without practice. See
i.e. W's theory of language for a mind blowing explanation.

I think the real question I would pose to the author is, what knowledge do you
think qualifies as 'explicit'? I think you will find your answers supremely
unsatisfying. If you don't, try Kripke's 'Wittgenstein's Paradox' and
Goldfarb's (admittedly much more dense) 'Rule Following'

------
Alex3917
> Tacit knowledge is knowledge that cannot be captured through words alone.

This definition is slightly wrong. Tacit knowledge can't be described in words
alone, but it can be captured through words alone.

One of the reasons we built FWD:Everyone
([https://www.fwdeveryone.com](https://www.fwdeveryone.com)) was to capture
the tacit knowledge contained within email conversations. When you can see the
entire conversation, you learn how people interact with one another and you
can learn to model your own communication based off of that. That knowledge
isn't contained in any individual sentence, paragraph, or message, but rather
as an emergent property that's only apparent in the context of an entire
conversation or many conversations.

There is a ton of value in this that can never be captured in a wiki, for
example.

~~~
bobbiechen
> you learn how people interact with one another and you can learn to model
> your own communication based off of that.

This strikes me a little like "By reading lots of good code, you can learn to
model your own code based on that". It probably helps, but a lot is dependent
on context.

The blog post goes into this with the long quote about choosing tools and
techniques for an appendectomy. How do you capture that sort of context in an
email thread? Annotations like "Based on X and Y factors, I chose to write Z",
where X and Y are not explicit in the email text?

I haven't looked too closely, but it seems to me that the primary value of
these email threads (in terms of learning communication) is to provide a body
of real-world examples - but there also needs to be applied experience (with
feedback) with written communication for the lessons to really sink in.

~~~
Alex3917
> The blog post goes into this with the long quote about choosing tools and
> techniques for an appendectomy. How do you capture that sort of context in
> an email thread?

I mean in terms of our tool, the knowledge is either already in an email or it
isn't. It's meant for retaining knowledge that's already being created anyway.
You certainly could purposely capture knowledge in email for the purpose of
being viewable and searchable in our tool (and some people do), but in that
case there may be other better tools.

------
quickthrower2
Been waiting ages for literally anything posted on commoncog.com to get
traction on HN, because it's all interesting deep writing about meta-human
issues, useful for "us lot" and invokes good discussion.

When I see a new post from commoncog, I don't read it right away. I think
"right need to carve out half hour of quiet uniterrupted time for that later".

It's one of the few I have on my mobile phone RSS reader, the others being
quanta magazine, and another interesting blog I found through HN.

So that's my praise, I recommend you add it to your readers too :-)

------
tener
We have neural networks in our brains which for some reason cannot be trained
without practice in real world. No amount of reading about riding will train
those real-time feedback loops that operate on much lower latencies then you
can formulate conscious thoughts.

This is a limitation of our brains and not fundamental property of knowledge
or information.

In AI neural networks which can ride bikes or recognize objects are easily
introspected and copied. In humans this isn't implemented ;)

~~~
hliyan
Isn't what we call thinking simply an introspection layer on top of our neural
network hardware? Sometimes I wonder whether the entirety of what we call the
mind is just an epiphenomenon that attempts to explain the workings of our
neural network _after the fact_.

~~~
goatlover
If that were true, then cognitive behavior therapy and meditation would have
no effect. It's more likely a feedback loop between introspection and the
neural network. Sometimes you need the slow, deliberate planning that comes
with conscious thought.

~~~
hliyan
But what if the urge to seek CBT is itself a part of our ex-post-facto
narration?

------
knightofmars
I believe this is how you learn:

* I watch you do it. * You watch me do it. * Then I do it.

I have to watch someone else undertake a task to understand it. After, I
attempt to undertake the task and receive feedback from the individual whom I
watched first. Then after I've gathered the knowledge I can do the task. The
context I learned about this approach was when I learned to use a chainsaw.
But it has served me extremely well in both learning and teaching other topics
over the years.

------
ncfausti
Does anyone know of a service or website that matches mentors with
apprentices?

I know there is
[https://www.apprenticeship.gov/](https://www.apprenticeship.gov/) but I am
thinking something more informal and online, e.g. a marketplace where you can
match and pay $X/30 min. of quick and focused Q&A.

~~~
agustif
[http://codementor.io/](http://codementor.io/)

I've used it a couple times to get help with roadblocks and such..

Getting a second pair of eyes on your code is nice!

------
sojournerc
>> The process of learning tacit knowledge looks something like the following:
you find a master, you work under them for a few years, and you learn the
ropes through emulation, feedback, and osmosis — not through deliberate
practice.

I feel fortunate to have stumbled into an organization where this was the case
as a junior engineer. The company wasn't ever wildly successful, but I feel
lucky to have worked with very smart people when I was very green, and
couldn't make heads or tails anything.

Patience was certainly needed on their part I'm sure, and such frustration is
likely what leads people to become pedagogical at times.

------
JamesLeonis
As a bit of a thought experiment; would Simulation be the closest we have
towards "Transmissionism"? I'm not arguing that it is or isn't, but whether we
can approach those non-verbal and tacit knowledge as encoded through programs
and data?

To throw out an easy counter-argument, we could say that
Simulation/Programming is like comparing Words to an Image, aka nothing of the
sort. Additionally, there is the difference between Simulation and Reality,
where simulation simplifies or glosses over many elements of reality. Looking
up the definition indicates that Passivity seems to be the key, and
simulations are anything but passive.

To give a concrete example of what I mean, in my early career I worked at a
defense contractor building a training simulator for a weapons platform. The
training was to mimic the same training on a gun range. Soldiers were graded
by the simulation as if it were the instructor with a sharp eye and a
stopwatch. It tested everything from how long you held the trigger (at least
three seconds), how you swiveled your head to scan for targets, identifying
targets and relaying them to your vehicle commander, etc.

I would argue that it goes beyond Transmissionism, as it now corresponds far
more to an actual reality than mere metaphors and words. However it does make
me wonder where the line might be, if it even exists.

------
memexy
In high school physics class there was one kid that seemed to be really good
so one day I asked him what his trick was and he said, "I just pretend I'm the
teacher". I thought that was a really clever trick. During class he was
figuring out ways of how to copy the teacher and it seemed to work. He would
consistently get top marks on tests. He was accumulating tacit knowledge
whereas everyone else was copying formulas and drilling problem sets.

------
unixhero
I wrote my master's degree on innovation management. Tacit knowledge was
termed by Michael Polyani and Nonaka and exploded this sub genre of knowledge
management and innovation management. I recommend reading their seminal
papers.

But it's all down to the type of knowledge involved in skills you have
acquired such as biking or walking, and things where you can extoll an
intuition versus explicit knowledge such as a pizza baking recipe.

------
rramadass
This is actually how knowledge was transmitted traditionally. As an
apprentice/student you just copied the master who would steer/nudge you in the
right direction occasionally. Otherwise you just did the activities blindly
until slowly you self-regulated and moved onto deliberate practice stage. This
can be most clearly seen in the study of martial arts. Musashi called it
_Heiho /Hyoho_ in his _A book of five rings_.

I believe the key here is to focus learning on the overall activity (i.e.
systems view) rather than the constituent individual pieces. Focusing on the
latter just overwhelms you with too much detail leading to doubt and
confusion. For example, in Software Development, if you try to focus on every
single aspect like Correctness, Error handling, Generalization, Optimization
etc. in the beginning you simply will never get anything done. Instead focus
on just getting "a program" done using whatever knowledge you have. Once that
is ready, then modify it deliberately for meeting all your other criteria.

------
ericmcer
This is why language/framework design is so interesting. After enough time
spent with one a developer will be running off tacit knowledge.

Extending/patching that doesn’t fit in with tacit knowledge is also dangerous.
React has done a great job of that, it looks much different than a few years
ago, but the changed behaviors never felt “wrong” internally.

------
TehShrike
When I finally learned how to ride a bike, I was annoyed that nobody had told
me "to keep the bike balanced, if you start to fall to one side, turn the
steering wheel in that direction".

\---

It's a good exercise to frequently try to verbalize your tacit knowledge. The
alternative is to constantly be appealing to your own authority.

Lots of people have faulty tacit knowledge.

------
ploubus
Michael Polanyi's "The Tacit Dimension" is a good starting point on the
concept.

------
obvthrowaway2
Tacit knowledge sounds like an untestable phenomenon, and simply lacking the
words to describe certain neuromotor techniques doesn't mean that it cannot be
communicated explicitly in theory. Perhaps in the future we'll have a way to
stimulate the brain in exactly the right way in order to communicate how to
keep your balance on (aka "ride") a bike.

Furthermore, articles that downplay the importance of practice, to me, seem
like a bad idea. In my experience, people who claim a high level of general
comprehension (but not technical) tend to lack the ability to implement any
facet of their "tacit knowledge" at even a basic level.

------
phkahler
Dear bloggers. I hate it when you spend several paragraphs explaining your
personal reasons for wanting to write about a topic, particularly when those
reasons have nothing to do with the topic at hand.

Don't talk about it, be about it.

~~~
dvtrn
_I hate it when you spend several paragraphs explaining your personal reasons
for wanting to write about a topic_

Literally the point of a blog. That's why it's _their_ blog.

------
__tg__
A long time ago in a philosophy of math class, our professor offered this
problem: upon hatching chicks have to be separated by sex. Experienced poultry
farmers know how to tell them apart from feel but it's not a process they can
describe. The problem then was: how would they teach it to a new hire? The
solution offered was that they have the rookie hold the chick in their hands
and guess while the experienced farmer corrects them. This was a great example
of how tacit knowledge is acquired.

------
elchief
And explicit knowledge (that you can explain to others) is more important than
tacit knowledge, if you're trying to coach or teach someone

Isiah Thomas was one of the best of all time, but was a disaster as a coach
[https://www.sbnation.com/2015/5/5/8553115/isiah-thomas-
new-y...](https://www.sbnation.com/2015/5/5/8553115/isiah-thomas-new-york-
liberty-knicks-raptors-pacers-cba-fiu)

~~~
joe_the_user
I don't think "knowledge that can't be put into words" is a good final
definition of the skills that allow people to achieve excellence. It's an OK
"first order approximation" but when it implies "nothing you can say will be
useful", it seems more like a hindrance than an insight.

I've studied martial arts and body work. Naturally, many of the skills
involved are taught hands-on rather than through a verbally specified sequence
of actions. And it's definitely true that balance or an effective stance can't
be taught by just sequences of positive commands ("stand straight, chin out"
or whatever). However, high level (or more effective) skills _can_ be taught
through a combination of hands-on direction and verbal direction telling the
student to "explore", to "relax", to "be aware" \- these verbal direction
represent internal, non-verbal processes ("balance centers", etc) and tells
the student to yield to these. That yielding lets these processes get the
skill and knowing how to so yield lets the skill be available. It's not
avoidable verbal but it's not a simple rationalistic recipe.

------
emmanueloga_
"When I pushed these people on their judgments, they would try to explain in
terms of principles or heuristics. But the more I pushed, the more exceptions
and caveats and potential gotchas I unearthed."

It is a popular believe that being an expert on something doesn't mean you
will be an expert on teaching that thing, but in this case it could also be
that any number of implementations was possible, and the seniors had more
clout or were more pushy.

~~~
forgotmypw17
I think of it the other way around: Until I can teach the thing to someone
else, I am not yet an expert.

------
dorkwood
It seems as if I've been using a different definition of deliberate practice
to the author. They seem to imply that deliberate practice requires a
regimented study program, but I've always seen it as "identify the things you
are weak at and drill those things, rather than repeating tasks you are
already comfortable with". Is there a name for the type of practice I've been
doing?

~~~
shadowsun7
Yes, K. Anders Ericsson (he of deliberate practice fame) calls it 'purposeful
practice'.

------
hugozap
I believe deliberate practice can work in the same direction if the
practitioner is aware of the fact that there will be huge gaps in the
knowledge acquired through practice.

I like the idea of discarding the results of exploratory processes that GeePaw
Hill elaborates very well. It removes the incentive of trying to reuse
artifacts that were created "while learning" and just bring back the lessons
learned.

------
ChrisMarshallNY
Most of my software design is "wordless." Part of it is because I have a brain
that is wired a bit "funny." I'm sort of "on the spectrum," and get into a
"fugue" when I code.

In fact, after coming out of the "fugue," I can have trouble with verbal
articulation.

But when I am in the "fugue," I can actually design a pretty intense system,
without writing down a thing.

------
atdixon
One very helpful thing to understand wrt this idea of "tacit knowledge"
especially in terms of understanding and managing personal relationships...

You or someone you know may very well become aware of (i.e., _come to know_)
what are your personal defects (insecurities, unproductive behavioral
predispositions, etc) -- but this is in no way _at all_ means that you will be
able to _change_.

------
darkerside
The John Boyd example is super interesting. My understanding is that he
essentially built a framework for thinking about dogfighting, the OODA loop.
Very similar to how the author put kids on tiny bicycles. You can't tell
someone what to think, but you can _design a system_ that makes it so that
they think about the right thing at the right time.

~~~
sitkack
This is how we "teleport" thought from one person to another, we have to
replay the same series of events that enable them to have the same thought
patterns. Communicating and educating is basically replaying the stage for the
same thoughts to form.

------
inanutshellus
“For the things we have to learn before we can do them, we learn by doing
them.”

― Aristotle, The Nicomachean Ethics

[https://www.goodreads.com/quotes/4184-for-the-things-we-
have...](https://www.goodreads.com/quotes/4184-for-the-things-we-have-to-
learn-before-we-can)

------
roywiggins
This is why every attempt to "systematize all human knowledge" cannot succeed.

~~~
galfarragem
Tacit knowledge concept connects a lot of dots. It was a missing piece of the
puzzle.

Really interesting article.

------
durmonski
Amazing post! I didn't know such type of knowledge existed. Eager to learn
more.

------
leoc
See
[https://www.youtube.com/user/troygrady](https://www.youtube.com/user/troygrady)
. Troy Grady is an extremely successful externaliser of tacit knowledge.

------
product1087
> “Because we want to use it as a database layer. Quite risky ah.”

Singapore represent!

------
thisisbrians
I kinda think he's talking about intuition. It's the non-verbal understanding
that underpins mastery in any domain. If deliberate practice is the means,
then tacit knowledge is the end.

------
lihaciudaniel
I'm agreeing with the idea of the article, but I believe that Tacit knowledge
which can't be attained with practice would call Talent or In-born gifts. For
example, no matter how much chess I'll play and deliberately practice for 20
years I can't beat Fischer, Kasparov, Karpov etc.. since they are talented
(Tacit knowledge) that doesn't mean they can't open their talent through books
like "Bobby Fischer teaches Chess" or books about chess by Karpov (but who
would do that during matches of chess). Deliberate Practice is the best way
and most fast method for acquiring a skill

------
keeptrying
Deliberate Practice leads to Tacit Knowledge.

Or rather the former trains the acquisition of the latter.

------
Shugarl
Is having a mentor necessary ? Can't it be gained in other ways ?

------
jvanderbot
Deliberate practice builds tacit knowledge. Uninformative article.

~~~
x3c
Immersion builds tacit knowledge. Deliberate practice may or may not require
immersion.

~~~
jvanderbot
I can see that. I just don't (didn't?) see deliberate practice as not
immersed. Fair point.

------
nednar
Tacit knowledge is the result of deliberate practice.

------
wellpast
Isn’t there already a long philosophical analysis of this phenomenon — know-
how vs know-what?

------
sebwi
In general, I agree with the notion that tacit knowledge is often more
important than explicit knowledge - and that it may actually be the very
essence of human expertise. However, it seems the author mixes some things up.

First of all, deliberate practice rests to a high degree on a) pre-existing
knowledge on the structure of acquiring a skill and b) an established feedback
standard that allows to evaluate your performance. These are obviously crucial
aspects. If you don't know what characterizes expertise and if you don't know
why you're not doing well - then it's difficult to make actual measurable
progress. That said, it doesn't mean you can't become an expert at all in a
field that does not have those elements currently available. It may just be
that you need to put more effort into doing it, seek a mentor known for
relevant skills or develop feedback mechanisms to evaluate your performance
[1].

Thus, I don't think the distinction made between tacit knowledge and
deliberate practice is really helpful. From my understanding, the concepts of
"tacit knowledge" and of "deliberative practice" operate on two different
levels. Tacit knowledge (or originally tacit knowing) refers to the implicit
character of some knowledge. Its counterpart is explicit aka codified
knowledge. Conflating deliberative practice with (the acquisition of) explicit
knowledge seems counterproductive to me. It seems to me that the author wants
to argue that deliberative practice only contributes to explicit knowledge.

I get that explicit knowledge may be needed to create learning environments
(and gained before through codification of tacit knowledge) that respond well
to the principles of deliberate practice. From my reading of Ericsson that
does not mean, however, that deliberate practice only works to build up
codified knowledge. Tacit knowledge is in itself a vague concept that is hard
to grasp. I wouldn't be confident to assert that building up tacit knowledge
happens without building up codified knowledge. Maybe someone knows more about
that?

Another aspect of the article that concerns me represents the part about the
acquisition of knowledge and expert systems. There seems to be another
conflation of concepts. It is referred to Klein who (in reference to humans)
warns about the overreliance on fixed procedures for decision-making. I agree
with that but nevertheless I'm having a hard time with the argument in the
article's context. For me this seems to be more of an argument about having a
human making a decision than about the superiority of tacit knowledge over
deliberative practice or even codified knowledge applied by a human. I get it,
humans can build up tacit knowledge and therefore have an advantage over
expert systems in previously unknown situations ... I just don't get the
relevance for human acquisition of knowledge here which the article wants to
be about.

A similar issue I have with the argument about the scope of deliberative
practice and NDM as better alternative. Now I have to say I heard about the
term NDM for the first time today (and I'm glad I got introduced, thanks!) but
from what's written down in the article, it doesn't really seem to be in
conflict with - or even that much qualitatively different compared to -
deliberative practice: "you find a master, you work under them for a few
years, and you learn the ropes through emulation, feedback, and osmosis". This
seems to be possible under the concept of deliberate practice as well.

To get a better understanding, I've read another article from the same author
[2] but I'm a bit confused. In the end, NDM just seems to offer more concrete
procedures to acquire effective and adaptable mental models (in terms of
deliberative practice) that help you to make better decisions. But that can't
be the catch of NDM, is it?

[1] I'm currently reading Ericsson's book "Peak" and he mentions the Top Gun
academy of the US Air Force as an example for the possibility to develop a
"deliberative practice"-like environment.The program was designed to enhance
figher pilots' performance by having those pilots surviving the initial air
fights in Vietnam to become teachers to new pilots. Establishment of good
practices took place through the constant exposure of the teachers to new
recruits and constant training on usual fight situations.

[2] [https://commoncog.com/blog/putting-mental-models-to-
practice...](https://commoncog.com/blog/putting-mental-models-to-practice-
part-5-skill-extraction/)

~~~
shadowsun7
This might help clarify my problems with deliberate practice somewhat:
[https://commoncog.com/blog/the-problems-with-deliberate-
prac...](https://commoncog.com/blog/the-problems-with-deliberate-practice/)

~~~
sebwi
First of all, thanks for your post! It was an interesting read and I've
subscribed to get updates.

Yeah, that was really helpful. I think the argument you make about
'fractionated pools of expertise' is actually the most important. I'm still a
bit confused about the differences between "practice" and "decision-making"
and their relationship to knowledge (either codified or tacit) but I guess
that will now be part of my list of things I want to learn more about.

------
cambalache
Blog posts are like youtube videos, you have to skip the first 30% to see the
"actual" start.

------
troughway
>[...] every time I touch on the topic of tacit knowledge, inevitably someone
will pop up on Twitter or Hacker News or Reddit or email and protest that
[...]

One of these is not like the others.

------
Kednicma
Tacit knowledge is the lowest rung of understanding. It's the understanding
that cats and dogs form, unable to talk but able to listen and consider. The
main difficulty is that, because one cannot express tacit knowledge, one
cannot reform or improve it.

Part of why operationalization is so important in the hard sciences is because
it gives us access to otherwise-inacessible things, including tacit knowledge.
The only knowledge that is tacit for the typical person is the knowledge of
how to move muscles. For example, to whistle, the tacit portion is the pursing
of the lips, but the rest of it is music theory which can be communicated and
taught using language.

~~~
mattkrause
> only knowledge that is tacit for the typical person is the knowledge of how
> to move muscles.

Thats's not really true.

If you are a native English speaker, it might surprise you to learn that
English adjectives have a default order. We normally say "the big red ball"
but "the red big ball" sounds decidedly odd unless there's an explicit
contrast ("No, not the blue one. I want the _red_ big ball"). This is
apparently taught in ESL classes, but neither I nor any of my native-speaker
colleagues remember learning it in school.

You have an "intuitive" model of physics in your head that allows you to
rapidly determine if piles of objects are stable without grinding through
balance-of-forces calculations. It's not exact, and deviates from reality in
interesting ways, but it's there.
[https://www.pnas.org/content/110/45/18327.short](https://www.pnas.org/content/110/45/18327.short)

You have all kinds of implicit priors that help you make sense of sensory
input. You have some idea of the speed and smoothness with which things move,
how an object's apparent size changes as you move towards or away from it and
how it might look under different lighting conditions. People share some, but
not all of these priors, and they're hard to elicit, hence the endless
discussion about The Dress that was either black/blue or white/gold.

~~~
Wistar
The Royal Order of Adjectives.

[https://www.lavc.edu/profdev/library/docs/Adjectives-and-
adv...](https://www.lavc.edu/profdev/library/docs/Adjectives-and-adverbs.aspx)

~~~
mattkrause
Exactly. There is a rule but I would venture that very few native English
speakers know it or were taught it; it's learned implicitly instead. I only
found out there was a rule because I stumbled across the phenomenon doing a
computational linguistics project.

My broader point (which I made poorly) is that native levels of language
proficiency require a mix of explicit and implicit learning. There are
certainly explicit rules for verb conjugation and agreement. Some things can
be learned either way, like adjective order. Others seem to be mostly
implicit: I can't give you a general rule for why "I asked her to marry me and
she agreed" sounds fine but *"I asked her to marry me and she concurred"
sounds weird.

