Critical thinking

[Enzo]

Oh, just idle thoughts. I was reading a couple books, the gist of which are that topic. Got me thinking about this industry. Electronics is abstract, you can;t see electricity, you can only see the results of its work. You can measure it going past, but that is like footprints in the snow made by unseen animals. But if you can;t grasp it in your head, you will never get it.

Around here, I preach troubleshooting, and I make an effort to present the basics of that process. There are guys who know a ton more electronics than I do. I know a lot of that, but I don;t consider myself an electronics expert. I'll go head to head with anyone troubleshooting, but my days of looking at load lines and such was 50 years ago.

A lot of troubleshooting is using logic and reason. You have to pose if-then questions and then gather the evidence to prove or disprove that premise. Some time ago I lamented that kids today come out of school ignorant. I saw that as a problem. Industry sees it as a problem and complains about it. WHen I mentioned it here, no one seemed to care. "Google" they said. Aside from growing a generation of ignoramuses, I note we also never teach anything about critical thinking in our schools. No formal logic. I studied logic, but it was a college course. Not the sort of thing they teach in grade school or vocational college. Not even cause and effect.

I can forgive musicians, it is not their job to be repairmen. But it is disheartening when technicians don;t understand the implications of simple things like swapping the speaker wires to locate the problem with a dead channel. "My left channel speaker didn;t work, so I swapped the speaker wires and now the right channel doesn't work. Must be my speaker, right?"

I won't go into it, but any logic course will present a list of logical fallacies. They even give them names. "Affirming the consequent." If my power tube is shorted, the B+ fuse will blow. The B+ fuse is blown. I must have a bad power tube, right?" Wrong. You may have a bad power tube, even probably, but the blown fuse doesn't prove that. Other things like arcing sockets, shorted rectifiers, shorted caps, and so on can also cause this. "If the moon were made of green cheese, it would have holes in it. The moon has holes in it, therefore it must be made of green cheese." No, other things can cause holes too. Maybe this one. "Look out the front door of my shop, if it is raining, the sidewalk will be wet. The sidewalk is wet, therefore it must be raining. Right?" No, someone could have hosed off the sidewalk. The water main could be broken. Lawn sprinklers could be on. People get the logic backwards. You need to demonstrate the premise, not the consequent. "If it is raining outside, the sidewalk will be wet. It is raining outside, therefore the sidewalk is wet." That works. We set up an if-then, and if the IF is true, then the THEN will be true. Very different from stating the THEN is true so the IF must be as well. We verified the premise.

ANother one I see ALL the time is what they call "post hoc, ergo propter hoc." That is Latin for "after this, therefore because of this." Classic examples are "I was playing with an overdrive pedal and the fuses blew. Must be the pedal blew the amp." Or recently, "I had a wrong impedance speaker connected to my amp and a power tube blew. That proves mis-matching impedance blows power tubes." Hardly. The human mind is wired to see patterns, even ones that are not really there. COincidences happen all the time. "I changed channels too quickly, and (something) blew. How can I avoid blowing it up like that again?" You didn;t blow it up. If an amp is going to blow up, it will almost always happen while you are using it, and that means SOMETHING was happening at the moment it blew. But that doesnl;t make it the cause.

Correlation is not causality. Just because two things happen together doesn;t make them related. Ever flip a switch and at the same moment some noise occurs? Like a car horn outside, or a firecracker popping, or a big truck rumble, whatever. It can be momentarily startling, but related? No.

Not saying we shouldn;t look for patterns and related events, but we cannot assume they are related.

I saw a light in the sky, and I didn;t know what it was. Must be aliens from another planet. Yeah, must be... Argument from ignorance.

Gerald Weber says XXXXX, and he has written a lot of books. It must be true then. Argument from authority.

SO and so says XXXX. SO and so is an asshole, so he must be wrong. Ad hominem agrument.

If this is remotely of interest, the first hit in google for logical fallacies was reasonable:
Fallacies

Maybe I am just nuts and no one cares about this. To me, this is the heart of troubleshooting. We need our young people to be able to think. We certainly need our technicians to think. When I interview tech candidates, that is the one thing I am looking for, the ability to think and reason.

[Steve Conner]

The ability to think and reason is completely passe, at least according to Wim Veen's "Homo Zappiens" concept.
http://www.oecd.org/dataoecd/14/25/38337941.pdf

The above (large) file shows what we're up against, and I say "we" even though I'm old enough to be Enzo's grandson.

I'm guilty of "zapping" as I'm supposed to be designing a DSP board right now.

[Neal]

Enzo, one of the things I love about your posts is that you have an answer to our questions AND you lead us through the process of finding that conclusion. On most discussion boards, I'll skim through and read any posts related to an amp I own, or that a buddy owns that I may have to look at in the future. Here, I try to read all of your posts, no matter what they refer to, because I know I'll learn something about troubleshooting and common sense.
Speaking of Gerald Weber and books, I know Enzo has mentioned writing a book about troubleshooting in the past, but time constraints have prevented it. I noticed that Gerald Weber's first book is basically a collection of articles he'd written for Vintage Guitar magazine. If some industrious soul would organize all of Enzo's posts here in a question-and-answer format, the book would be 90% finished! Hint, hint.

Ever flip a switch and at the same moment some noise occurs? Like a car horn outside, or a firecracker popping, or a big truck rumble, whatever. It can be momentarily startling, but related? No.

I saw a comedian shortly after a big California earthquake years ago. He said, "You know that somewhere in California, right at the moment the earthquake hit, some father was saying, 'Hey, son.... Pull my finger!'"

[Jazz P Bass]

Sense.
Decide.
Act.

[Rhodesplyr]

Maybe I am just nuts and no one cares about this. To me, this is the heart of troubleshooting. We need our young people to be able to think. We certainly need our technicians to think. When I interview tech candidates, that is the one thing I am looking for, the ability to think and reason.

I cared enough about it to devote my life to earning a doctoral degree and teaching literary history, a large part of which involved teaching methods of critical analysis and identifying illogical and specious arguments.

But when State budget cuts were mandated in 2009, mine was one of the positions that was cut. Now, do you think the university's basketball coach lost his job? Or, to ask the question another way, how dangerous to a culture, over the long term, are misplaced priorities?

[Cygnus X1]

Thank you Enzo.
For elucidating what seems natural to some but appears as genius talent to many.

My IQ is nothing to write home about but I love "arguing" with Mensas.

I have achieved the stellar educational achievement of "college drop out" and "continuing education".
Because work and making money became far more important.
I must have been gifted with critical thinking skills.
I have been described as "artist-pragmatist" and such nonsense.
Served me well for many years as a machinist and shop-engineer.

I just know for a fact that arguing logically is highly frustrating with someone who mixes cause with effect.
Then I appear as a smartass...I guess because I am.
Going against the grain, that's what I do!

For example this:
Rhodesplyr...how many tickets and alumni dollars rolled in for your work?
Very sad, but too true.
See?
Pragmatism.
Money talks.
Your talents WILL be appreciated by someone, hang in there.
You have what it takes to survive.

On topic, I am glad to see my two sons suffer from the same affliction as I,
which makes them unpopular until someone else is "stuck".
They don't take the time to teach, they just get the job done.

[Enzo]

I once knew a very smart man. He wrote mighty treatises on the nature of matter and such things. He once told me he knew what Mensa was all about. "Mensa is a way to get $30 dollars from smart people."


I don;t want to drift off into philosophy, my point was really a practical one. But at that risk, I often hear people confusing various terms. I have my own definitions I suppose, that may or may not agree with those of academia. But to me "smart" is three things: knowledge, intelligence, and wisdom. KNowledge is information, intelligence is the mental ability to assess and analyze, and wisdom is the ability to differ between that which is needed and that which is not. You need all three to be "smart." SOmeone who knows a lot can still always make the wrong conclusion with that knowledge. Someone with tons of native intelligence can still be an ignorant fool. And someone with great judgement can lack information. SO you might wind up arguing with someone who knows many things and cannot succesfully integrate them. or with someone who is intelligent but never bothered to learn any background information.

[trevorus]

Critical thinking is something that is getting lost more and more these days. I see a ton of people who can't even figure out things like a GFI being tripped causing their bathroom lights not to work. (I work apartment maintenance) Thankfully, I was raised around cars, construction sites, maintenance jobs, etc., so the diagnostic process and the critical thinking that goes along with that was part of my upbringing. My father taught me to look at a problem and approach it in a way to dissect it, not just throw parts at it... Also, the phrase, "I don't know," should always be followed by, "but I can find out." Especially in the age of the internet, and many reference sources a click away. With that, you still need the critical thinking to differentiate between the BS and fact, otherwise you end up buying IEC cables that cost $300 and other nonsense like that.

BTW, thanks to Enzo for being such a resource around here. I really do learn a lot from your posts, E.

Edit: I have been thinking a lot recently about the correlation between statistics and causality. There is a massive amount of information out there about the link between causality and statistical data. One such thing is the diagnosis of ADHD these days. I do believe there is a disorder out there, but diagnosing kids that don't want to pay attention in school, but can play video games for 6 hours straight doesn't automatically mean ADHD... But some people tend to believe it does.

[Enzo]

Lots of correlations. people are on an obesity kick at the moment. get the Twinkies off the school menu. yeah yeah, must be the Twinkies. COUldn;t possibly be the removal of phys ed from many schools nor the fact that kids go home from school, sit down in front of a TV and play X-box the next 6 hours. WHat was the last time you saw a pickup softball game on a residential street? But it must be the Twinkies.

Kids start showing the signs of autism around 2 years of age, so naturally, anything that is routinely done to kids - vaccinations for example - just MUST be the cause.

Correlations can be drawn between SAT scores and heigth. COnsistently. It seems that kids 5 feet tall generally do much better than kids who are three feet tall. Ignore the fact that five year olds won;t score as well on SATs as HS seniors, it must be the heigth.

Speaking of statistics and such, there is an excellent litle book, "Innumeracy" by Paulos. Easy to read, not particularly technical. Innumeracy is his word for the mathematical equivalent of Illiteracy.

[Brad1]

Yep. Logic doesn't make sense to a lot of people.

I've recently started some classes to fill in a couple holes in my resume. Most of those younger kids DO seem completely lost...and frankly...kind of screwed up. Break time conversations they have all seem to be about them comparing all their legal problems, and putting the blame on someone...anyone...else.

Anyway...they started us off with some basic math for formulas, etc. There was a problem on a test that I got marked wrong, but I argued my point, and he changed it. (The instructor is fairly laid-back.)

Here's the problem:

"The area of a rectangle is 76.2 ft squared. Length is 34 ft. Find its width." (There were no instructions calling for rounding up or down, etc.)

A) 2.2 ft.

B) 2.6 ft.

C) 2.0 ft.

D) 2.3 ft.

E) 1.2 ft.

Of course, that's easy. 76.2 / 34 = appx. 2.241 ft width. Since the exact number wasn't listed, most people may choose 2.2. It IS actually closer than 2.3 is. After having written on the test demonstrating I knew how to solve the problem...I chose 2.3 ft.

Why?

I asked the instructor "Who uses area measurements the most? Contractors, right?"

"I'd guess that's right," he said.

"Well, if I'm the contractor, and I tell my guys to "round" numbers in their measurements to order tile, and then they have to drive 65 miles to get that tile, and 65 miles back...I'm going to tell them to round up. If I was going to round off measurements, I want them bringing enough back to finish the job, and not have to hold up progress...and maybe even the next step...for half a day for them to run back in to get just a few more tiles. I'll lose money by downtime, them not working, and fuel, etc. I'd rather have them bring back just a bit more, than not enough. Besides, that "bit more" of extra tiles can be used for odd places. That's why I rounded up. I was thinking in a "real world" situation."

"Well", he said, "you DID show the math, and got the exact answer. I'll give you this one just for being so creative with your explanation. In the future, though, just round to the nearest answer. Don't consider math tests as "real world".

Math teachers. Teaching math, but not real-world logic.

That's just me. I like to think outside the box. He thought it was kind of amusing, and commended me on my initiative...and then told me to do it their way from now on.

Anyway...about the "after this, therefore because of this."

"After this" should always be considered, but not taken as the "definite cause of that". Some things are obviously caused by a change, replacing an old cap in an otherwise working amp, and it blows up the cap...obviously you've installed an electrolytic backwards, used way too small voltage values, etc. That's a definite cause of the last thing you did "after this".

Some changes could affect other things. Anything you do in a computer to change hardware, add software, use hardware flash updates, etc. is capable of changing the previous relationships of anything else, to the system. Installing "plug'n'play" or different hardware can change IRQ assignments, etc., which may freak out your recording interface that you've spent weeks tweaking perfectly. It's easy to scream "That new card messed up my recording interface!" The card didn't do it. Windows did. Now, you just have to go in and figure out how to reconfigure things, if you still want to use the new card. Otherwise, remove it, and roll back Windows to the previous configuration.

Changing old components in electronics has the possibility of this causing that. Every component has a tolerance rating. As you all know, with age and use, those tolerances drift out of spec. When you have dozens of things drifted out of spec, each affects the other. Things get weaker, and more susceptible to meltdown or blowing up. If each thing has been slowly adjusting themselves over time so that they are actually seeing, maybe, lower voltages or current because of something...and then you change a few things to bring up things more quickly and more powerfully, then those old things left in may not be able to handle the new brute-force, when they were used to Wimpy. It's not the new components' fault. They didn't cause it. They are doing what they are intended to do. It's the old parts. It's their fault. Conversely, old parts can cause the ability to take out a brand new part, by the rest of the circuit running it way out of its range. You didn't buy a crappy transformer. Don't blame it. Just because that's the last thing you changed, it doesn't mean IT caused it.

Tracing circuits on something like a multi-board Roland keyboard is always fun. "Well... it doesn't work AFTER this IC...therefore it's this IC!" Not necessarily. It depends. It could be something else connected to that IC, and depending on how many pins it has, it could a LOT of things. It could be anything at any input or output of that IC that shares any connection with that IC.

Or, it could just be the IC. At least it's narrowed down.

That's all I've done all my life, is diagnostics and repair of mechanical, electromechanical, electronic and computer stuff. I'm no engineer, but I know the basics of troubleshooting logically. The very first logical thing is to use your senses. Eyes, ears, touch, smell...(I guess taste is related to smell, but I don't taste circuit boards or ball bearings).

Look for the obvious, first. If nothing is obvious, then start digging in. After digging in a while, many times, you'll find it was an obvious thing you overlooked while looking for the obvious, because you dismissed it as being "obviously NOT the problem"!

I just shake my head, utter a curse word, and tell myself to not assume things, again.

Until the next thing I'm working on.

Brad1

[Enzo]

yes, one thing can easily cause another. Operative point was, that two things, one following another in time are not necesarily causally related.

Case in point. REplace a bias filter cap and the new one immediately explodes, yes, chances are you installed it backwrds. Chances are... You might also discover that ther is a shorted power tube or a power tube in the socket wrong (broken off center peg) putting B+ on the bias supply and causing the damage. The backwards thing is likely, but we cannot assume it to be the case from a logic point of view.

But I am much more concerned over examples like "I installed a new bias filter cap, and the very next night, my power tubes blew a fuse. Must be that cap, right?"

[drewl]

My seven yr old son is quite adept at "repairing" things already, he sees dad do it so of course kids emulate their parents.

I always make it a point to explain how things work, and teach him how to use the same reasoning applied to other things.

parents need to fill in the gaps of what kids don't learn in school.

[km6xz]

Interesting thread. The problem, and it IS a problem on many levels, is cultural to a large degree. Some societies make thinking and acquiring knowledge a priority for child development, and hold it in esteem. When writers, scientists, artists are held in higher regard than wealthy or celebrities, a child tends to have a different set of values and priorities than in the US of today. I see that dramatically in my travels and living in other countries, although all are going through similar shifts in values but to a lesser extent than the US. That might be a ill-omen for those other society's future as mass communications, consumerism and internet undermine knowledge and value of thinking.
The simple reality is that there is no penalty for being stupid or glorying it in the US now, survival is not really influenced by being a poor thinker or being ignorant. Knowledge has less and less value when opinion trumps fact or reasoning as is the current social trait.
One obvious difference between the US and most societies I encounter is the nature of education. In most of the world, a child's education is a societal process involving everyone reinforcing the learning activity. In the US, it is left primarily to the schools for a few hours of the 5 days a week. Education or being "educated" is having a highly specialized career task oriented training and certificate. No where else would it possible for highly specialized professions be practiced, with success, by people who know only their career specialty and know or care little about how their work fits into the overall scheme of reality. For example I could not imagine an "educated" person in almost any random country not know a great deal of fields seemingly unrelated to their professional specialty. Almost uniquely, I meet American doctors or lawyers regularly who know nothing of history or the arts. Being educated in the US means career trained for a job. In much of the world, educated means having a broad range of familiarity with diverse fields that are seen as all relating to each other. For example knowing history and geography would be considered a natural fit for an artist or dentist, or mechanic. Around my adopted home city, it would be embarrassing for a street sweeper to not know some basic fact of history of another country or great literature. They would be genuinely embarrassed if they could not answer a question about the capitol of some obscure country or recite their favorite poetry. The value of knowing is not based on how much money it will generate or cost but how well the person is developed.
All this related directly to the sad state of technician skills. I see that it is really hard for a lot of hobbyists or even techs working as their job, to think through a problem without jumping to conclusions which do not fit the evidence and being willing to accept any opinion offered. Since it really makes little difference in lifestyle, income or effectiveness to know more or how to think, there is little incentive to acquire the skills. In most societies, it would be a matter of personal pride to know something and be willing to put effort into acquiring the knowledge.
Business and industry recognized the poor pool of technical job candidates years ago and altered the tasks to fit the available talent or lack of talent. For example some large companies funded training programs in community colleges in order to expand the number of applicants who had a set minimum skill level 40 years ago. Those programs have been mostly dropped when the problem became hopelessly widespread. The products, regulations, business models had to change to fit the more limited breadth of skills of workers, even at higher management positions....particularly higher management positions where wide spread ignorance is very harmful.
The US is really not competitive with many other countries for products and services in fields which the US once dominated in innovation and quality. Yet that lack of competitiveness and basic living competency that has become the norm in the US is ignored and blame is placed on easy targets that avoid personal responsibility in the matter. No, the country is not going down the tubes because of a single politician or whoever, it is going down because the persons saying that is so willfully ignorant. The problems are deep to the core of the society and its values that keep getting passed on to new generations. People who glorify ignorance and those who profit from it, raise even more ignorant offspring.
I notice, when visiting countries, what the society priorities are on, do they have more football stadiums than museums or concert halls for example. The city in the US I grew up in has 3 museums, and it has a metro population of 1,000,000. It has been stated that less no developed country has the arts less accessible. My adopted city has 254 museums that are well attended. 1% of Americans, according to one survey, have attended a ballet. 4% have visited art galleries other than on school field trips. It is not just ignorance that over 50% do not believe in evolution but believe the earth is younger than 10,000 years, it is willful ignorance. How could such a person possibly think through a problem of a guitar amp, or a minor financial decision or make a reasoned decision about government policy? They are all related and all suffer from the same willful, infuriating, debilitating ignorance. Those problems are all related because, as a broadly educated person knows, everything is related.

[Mark Hammer]

As "the psychologist", I'll try and add a different quarter twist to what is already a worthy discussion.

Godfather of cognitive development theory, Jean Piaget, noted that the general tendency of reasoning is to transition from the immediate (in infancy) to the not-necessarily-immediate-but-concrete in childhood, to the increasingly abstract across adolescence and into adulthood. What has preoccupied many researchers since those early days was just exactly HOW the transition occurs, both in terms of what it looks like, how quickly or slowly it happens, how broadly or uniformly it happens, and what makes it happen.

One of the things you see is that, while there are often wholesale "shifts" in thinking, the general pattern is for people to demonstrate greater abstract reasoning in some areas before others. And the areas they demonstrate abstract reasoning in are those where they have more regular experience. Ten year-olds will manifest ridiculously high-level abstract systems reasoning about their favourite video games, yet reason in the most stupidly concrete ways about household chores, homework, and similar. That's not intended whatsoever as a criticism, but as a reflection on how sheer amount of time devoted and interest can lead to substantial qualitative shifts in capability withn the same person.

More recently, the role of cumulative experience and practice as the basis for higher-order thinking has been thrust into the public eye by Malcolm Gladwell in his book "Outliers". One of the things we see across the research on skill-acquisition and expert/novice differences is that greater exposure to, and involvement with, a body or domain of knowledge, is associated with better organization within that body of knowledge. That organization, in turn, is what permits the reasoner to efficiently distinguish between the relevant and irrelevant information in any problem they might encounter withn that domain. It's what allows high-performance athletes to "see" an opportunity as quickly as they do and take advantage of it, whether it is making a pass in basketball, poking a rebound in for a goal in hockey, or picking off an interception in football.

That same cumulative experience and active participation (which also includes actively thinking about the subject matter even when not physically immersed in it) facilitates more abstract reasoning - in the Piagetian sense - as the learner/thinker focuses less on the details, and zooms out more toward the birds-eye or systems view. But there is no denying that the systems view is best acquired through cumulative experience and is not really something that is easily taught, and often not even something one can actively resist or refuse to learn (though some horses refuse to drink at the trough).

So what Enzo calls "critical thinking" is something that I elect to recast as abstract systems thinking. To my mind it is less a question of willingness to think in that manner than it is a question of capacity to think that way. I suppose if there was any sort of societal or cultural influence on the likelihood of it happening in any individual, we might chalk it up to a few things:
a) the increased emphasis on specialization, whether in music, education, career path, or web search. The "bricoleur"/generalist is not dead, but doesn't find much encouragement these days.
b) the shift over the last 35 years to a more "adolocentric" society in which that which came before one's own limited experience is treated as having limited relevance, thus compromising any individual's opportunity to collate a lot of knowledge and arrive at higher-order systems thinking. Stated another way, if you're amnesic, you rarely get to be wise.

This is why whenever I see some posting from a kid wondering how to get up to the level of the old farts - the "How do I learn?" question - I encourgae them to collect schematics in binders, to pore over them, to keep staring at that which has come before, even the stuff you might not think of as immediately of interest, until the patterns start forming. Similarly, one has to build and fix and build and fix until the "common sense" begins to be forged.

Experience, not much substitute for it, eh?

[Zipslack]

Oooh....as a technician and an educator, I've got to weigh-in on this. First off, my education background is electronics with some engineering curriculum. For the past 11 years, I've been teaching basic electronics at the high-school level. I've seen a steady decline during my time in critical thinking skills as well as a DESIRE to understand what is happening. My personal theory is that schools/government put too much emphasis on standardized tests (teaching to the test - basic skills and knowledge without critical thinking). In my own program, my students have to take a standardized exit exam that is ALL MULTIPLE CHOICE - just problems and definitions - no skills testing at all. I try to spend time teaching my students, "This is how the book works, this is how the real world works." It's depressing - I see fewer students each year that are willing to dig deeper and make an effort to understand and analyze.