Bias- evaiuating audio equipment

Gregadd

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Apr 20, 2010
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#1
A short Google search revealed this:


Expectation Bias

The tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations. (VSGCB)

This is when we only agree with the data that we like. My guess is that we rarely notice we’re doing. I’ve seen this tendency manifest when we’re drawn into heated arguments.
http://longgame.org/2010/09/expectation-bias/

We often cherry pick specifications and measurements to support our arguments.

I think that many of us discuss expectation bias when in fact we mean:

That we hear something because someone told us what we should hear.

The Power of Suggestion

The power of suggestion is everywhere. It's almost a part of human nature. So my guess is, you landed here to find out what's in it for you.

A lot.

Knowing that you are susceptible to getting the swine flu by exposing your self to someone who has it, gives you the power of choice to take what ever action is necessary to protect yourself. This puts you in control of your actions, that get you the things YOU want. Or in this case what you do not want.

Knowing you are susceptible to making choices, by exposing your mind to what others want you to think, puts you in control too.

For example, take a class of students. They're going over the answers to their tests with the teacher.

She calls on one student, "Tom, what's the answer to #3?" and Tom replies, "A". So, then maybe the teacher turns to another student and asks the same question to Jim. Lets say Jim thinks the answer was "B" , however Jim gives the same answer "A" because Tom did.

And I'm sure you know this is called...peer pressure.

The statistics say that something like 65% of us will give the wrong answer just because we heard someone else say it, even if we know it's the wrong answer.
http://www.real-hypnosis.com/powerofsuggestion.html
 
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Gregadd

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Apr 20, 2010
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#2
Wikepedia gives what I believe are informal definitions of thsee cognitive biases.

Many of these biases are studied for how they affect belief formation, business decisions, and scientific research.

* Anchoring – the common human tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions.
* Attentional Bias – implicit cognitive bias defined as the tendency of emotionally dominant stimuli in one's environment to preferentially draw and hold attention.
* Backfire effect - Evidence disconfirming our beliefs only strengthens them.
* Bandwagon effect – the tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behavior.
* Bias blind spot – the tendency to see oneself as less biased than other people.[2]
* Choice-supportive bias – the tendency to remember one's choices as better than they actually were.[3]
* Confirmation bias – the tendency to search for or interpret information in a way that confirms one's preconceptions.[4]
* Congruence bias – the tendency to test hypotheses exclusively through direct testing, in contrast to tests of possible alternative hypotheses.
* Contrast effect – the enhancement or diminishing of a weight or other measurement when compared with a recently observed contrasting object.[5]
* Denomination effect – the tendency to spend more money when it is denominated in small amounts (e.g. coins) rather than large amounts (e.g. bills).[6]
* Distinction bias – the tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.[7]
* Empathy gap - the tendency to underestimate the influence or strength of feelings, in either oneself or others.
* Endowment effect – "the fact that people often demand much more to give up an object than they would be willing to pay to acquire it".[8]
* Experimenter's or Expectation bias – the tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations.[9]
* Focusing effect – the tendency to place too much importance on one aspect of an event; causes error in accurately predicting the utility of a future outcome.[10]
* Framing effect – drawing different conclusions from the same information, depending on how that information is presented.
* Hostile media effect - the tendency to see a media report as being biased due to one's own strong partisan views.
* Hyperbolic discounting – the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs, where the tendency increases the closer to the present both payoffs are.[11]
* Illusion of control – the tendency to overestimate one's degree of influence over other external events.[12]
* Impact bias – the tendency to overestimate the length or the intensity of the impact of future feeling states.[13]
* Information bias – the tendency to seek information even when it cannot affect action.[14]
* Irrational escalation – the phenomenon where people justify increased investment in a decision, based on the cumulative prior investment, despite new evidence suggesting that the decision was probably wrong.
* Loss aversion – "the disutility of giving up an object is greater than the utility associated with acquiring it".[15] (see also Sunk cost effects and Endowment effect).
* Mere exposure effect – the tendency to express undue liking for things merely because of familiarity with them.[16]
* Money illusion – the tendency to concentrate on the nominal (face value) of money rather than its value in terms of purchasing power.[17]
* Moral credential effect – the tendency of a track record of non-prejudice to increase subsequent prejudice.
* Negativity bias – the tendency to pay more attention and give more weight to negative than positive experiences or other kinds of information.
* Neglect of probability – the tendency to completely disregard probability when making a decision under uncertainty.[18]
* Normalcy bias – the refusal to plan for, or react to, a disaster which has never happened before.
* Omission bias – the tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions).[19]
* Outcome bias – the tendency to judge a decision by its eventual outcome instead of based on the quality of the decision at the time it was made.
* Planning fallacy – the tendency to underestimate task-completion times.[13]
* Post-purchase rationalization – the tendency to persuade oneself through rational argument that a purchase was a good value.
* Pseudocertainty effect – the tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.[20]
* Reactance – the urge to do the opposite of what someone wants you to do out of a need to resist a perceived attempt to constrain your freedom of choice.
* Restraint bias – the tendency to overestimate one's ability to show restraint in the face of temptation.
* Selective perception – the tendency for expectations to affect perception.
* Semmelweis reflex – the tendency to reject new evidence that contradicts a paradigm.[21]
* Social comparison bias – the tendency, when making hiring decisions, to favour potential candidates who don't compete with one's own particular strengths.[22]
* Status quo bias – the tendency to like things to stay relatively the same (see also loss aversion, endowment effect, and system justification).[23][24]
* Unit bias — the tendency to want to finish a given unit of a task or an item. Strong effects on the consumption of food in particular.[25]
* Wishful thinking – the formation of beliefs and the making of decisions according to what is pleasing to imagine instead of by appeal to evidence or rationality.[26]
* Zero-risk bias – preference for reducing a small risk to zero over a greater reduction in a larger risk.
 

JackD201

[WBF Founding Member]
Apr 21, 2010
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#3
*Wishful thinking - Buying a pair of pants too small for you expecting you will lose weight and fit in to them
 

Orb

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Sep 8, 2010
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#4
Unfortunately wiki is rather poor when it comes to bias information but handy for the list, which is far from complete and omits some other biases that have fundamental affects on the approach for some scientific studies-tests; such as the AB order bias when one is unsure of differences I mentioned in the past.

If I get the time and if others are interested (this requires a fair bit of reading to follow and not skimming) I may find some of the studies-articles I have.
Cheers
Orb
 
May 30, 2010
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#6
Greg,

Although this is a very interesting discussion, I do not believe that understanding bias mechanisms and fundamentals can help avoiding it. IMHO, the only way of completely avoiding it is isolating the main subject of choice from outer influences, something that is not practical for high-end selection. To what level bias can impart our decisions is the critical aspect, and will vary from people to people.

IMHO, we can split audio evaluations in two broad lines - evaluations carried by developers who want to establish the preferences for general public, in order to maximize their success, and individual evaluations, where some one is just selecting equipment for his listening pleasure. Somewhere in the middle of these extremes we have the typical evaluations carried by forums members to feed debates.

Sometimes we seem to forget that sound reproduction is an individual process, and all we can do is statically analyze the data coming from many people to try to establish general assumptions.
 

flez007

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Aug 31, 2010
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#7
I just experienced this (again) biased position while listening several rooms last week, biased to what I liked from the last one I liked, biased to the sound I like, biased to colorations I accept, etc.. For me this is a matter of expectations and mis-judgments when it relates to soundbequipment evaluations. I am totally in with this thread, and Gragadd... Thanks for sharing the list.
 

Orb

New Member
Sep 8, 2010
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#8
Heya Micro,
you can debias if the person is trained to understand the specific bias-mechanism involved.
What though I am not sure can be debiased (as I have not seen any research relating to this side of the mechanism) is the chemical related bias such as expectation bias (also applicable to placebo effect) that improves the enjoyment factor (see the mOFC studies), that bias also applies to drug addicts at the time of preperation, so maybe it could be deconditioned *shrug*.
Big unknown anyay, and compounding this are also perception biases.

Bear in mind many biases are the heuristic-determination process shortcutting the need for all the information to be factored in; for various reasons, which I do not think are necessarily important though to here.
This is why it is possible to debiase-decondition a person's approach, but this is not a simple universal solution and is also dependant upon the person involved.
But then that could be said about designing scientific tests that exclude biases.

Cheers
Orb
 

Orb

New Member
Sep 8, 2010
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#9
Here is one good paper that examines biases closely related to audio, there are quite a few others I have but having problems finding them (some do not seem to be available online).
I will try to find online one of the better debiasing papers I have read, but will need time and unfortunately busy now for most of the day.
Anyway the following is a good read on many audio related biases and effect.
On Some Biases Encountered in Modern Audio Quality Listening Tests—A Review*
http://www.acourate.com/Download/BiasesInModernAudioQualityListeningTests.pdf

Cheers
Orb
 

Gregadd

WBF Founding Member
Apr 20, 2010
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#10
We are the result of our collective experiences. That makes us who we are. Awareness of our bias is probably more important than not having any. For example there was a time I would not even test drive an American car, or listen to digital. OTOH a truly neutral person would be quite boring. One should be passionate about his beliefs.
 

mep

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Apr 21, 2010
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#11
I developed a bias against my Jadis Defy 7 MKII. I would look at it with the expectation that it was going to eat an output tube at any moment and take a cathode resistor and cathode fuse with it. I had the expectation that every time I had to check the bias that it was going to be a pain in the ass.

Flipping a 100 lb amp on its side, removing the bottom plate, installing a set of dummy load resistors, measuring the bias on each tube in each row of three tubes and only having one bias pot to set the bias for each bank of three tubes never made any sense to me. You could never set the bias exact for each tube as a result, you had to add the bias voltages together and then average that bias to come close to the optimum bias value.

I became so fed up with the bias issue that I became biased against the amp and I sold it. I had the expectation that my audiophile life would become easier as a result of shedding this bias.
 

Gregadd

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#12
Probalby not a bias because it was based on actual experience.
 

flez007

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#13
I often hear folks say on the third day of an audio show, that rooms sound better, (claimed that the electronics is left on continiously and thus reaches full potential).....however, I think there is more a psychological thing going on..

on the first day for sure one is "hunting" down rooms and equipment to find out if they "sound" good, the next day are more hunting and perhaps affirmations on revisits to some of the same rooms, and also "getting into the swing" of the show (sort of like a habit..and being more relaxed) and finally the last day being there more to "enjoy" the sound or "discover" and less to analyze, ie a more relaxed environment.

This I found in the shows I have attended that were trade shows in other industries, the third day was always more relaxed, the enviroment and mental state more relaxed and familiar.

Just wondering

Tom
Agreed 100%
 
Jul 1, 2010
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#14
For example there was a time I would not even test drive an American car, or listen to digital. OTOH a truly neutral person would be quite boring. One should be passionate about his beliefs.
This is not passion it is prejudice; it is not belief it is bias. Unless, of course, you had personal experience with every American car. I'm not judging, by the way, I had exactly the same bias, still do to a great degree.

I developed a bias against my Jadis Defy 7 MKII. I would look at it with the expectation that it was going to eat an output tube at any moment and take a cathode resistor and cathode fuse with it. I had the expectation that every time I had to check the bias that it was going to be a pain in the ass.
This is not bias; that it was going to be a pain in the ass is a logical conclusion based on personal experience.

Tim
 

Gregadd

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Apr 20, 2010
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#15
""This is not passion it is prejudice; it is not belief it is bias. Unless, of course, you had personal experience with every American car. I'm not judging, by the way, I had exactly the same bias, still do to a great degree."

I'm an American male. When I was not thinking about girls, I was thinking about cars. I was passionate against American cars. I was passionate for Foreign cars
 
May 30, 2010
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#16
I often hear folks say on the third day of an audio show, that rooms sound better, (claimed that the electronics is left on continiously and thus reaches full potential).....however, I think there is more a psychological thing going on.. (...)
Tom
Although it can happen, IMHO it is not what happens most of the time. Although I am not a member of the industry, I have been in following closely several shows since before day one as a good friend of several distributors. Although it should not happen, as they want to present the last developments, many times the equipment is received without burn-in and they contact with it for the first time at the show.

They set it up in an hurry, and during the the first days, using the feedback and the advise of experienced visitors, a few things are perfected, sometimes a few elements of audio treatments are added, the type of music and levels are more conveniently chosen (some recordings even go in the forbidden list :rolleyes:), one raw of chairs mysteriously disappears and in the last day the perceived sound of the room has really improved.
 

MylesBAstor

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Apr 20, 2010
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#17
I often hear folks say on the third day of an audio show, that rooms sound better, (claimed that the electronics is left on continiously and thus reaches full potential).....however, I think there is more a psychological thing going on..

on the first day for sure one is "hunting" down rooms and equipment to find out if they "sound" good, the next day are more hunting and perhaps affirmations on revisits to some of the same rooms, and also "getting into the swing" of the show (sort of like a habit..and being more relaxed) and finally the last day being there more to "enjoy" the sound or "discover" and less to analyze, ie a more relaxed environment.

This I found in the shows I have attended that were trade shows in other industries, the third day was always more relaxed, the enviroment and mental state more relaxed and familiar.

Just wondering

Tom
And of course that accounts for the fact that many manufacturers fine tune the sound of the room over the course of the show eg. move the speakers around, recheck and reset cartridge alignment, let new electronics and speakers break in (yes exhibitors still bring say brand new speakers to shows), etc.

And how many attendees know what has been done?

Just saying.
 

jazdoc

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#18
Another great thing about shows...it a painless way to challenge your assumptions and step out of your comfort zone. Charles Darwin once said that when confronted with a hypothesis that challenged his beliefs, it was imperative to deal with it immediately. Setting aside such a challenge for later generally meant never confronting it. By nature, we tend to dismiss challenges to strongly held beliefs.

I'm a vinylphile, but I spent way more time listening to digital, especially server based systems at RMAF. While I'm not quite ready to turn in my analog rig, I was very impressed by the tremendous strides that digital has made. Indeed, if I was starting out, I would certainly begin with a server based system.
 
Jul 1, 2010
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#19
""This is not passion it is prejudice; it is not belief it is bias. Unless, of course, you had personal experience with every American car. I'm not judging, by the way, I had exactly the same bias, still do to a great degree."

I'm an American male. When I was not thinking about girls, I was thinking about cars. I was passionate against American cars. I was passionate for Foreign cars
Fair enough. I drive simple, reliable Japanese cars until they've drawn their last breath because cars are a horrible investment, and in good times and in bad, I'd rather put my money elsewhere. So I probably don't understand at all. :)

Tim
 
May 30, 2010
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#20
(...) Flipping a 100 lb amp on its side, removing the bottom plate, installing a set of dummy load resistors, measuring the bias on each tube in each row of three tubes and only having one bias pot to set the bias for each bank of three tubes never made any sense to me. You could never set the bias exact for each tube as a result, you had to add the bias voltages together and then average that bias to come close to the optimum bias value.
Mep,

It is a pity you never found someone who could sell you the proper set of matched tubes needed for the Jadis, and were badly informed on biasing techniques. I have owned the DA7 and Defy and it is really easy to re-tube if we understand that it used a mixed mode of cathode self bias and grid biasing with four independent groups of there matched tubes. Also I never needed the folkloric dummy resistors you refer.

Perhaps you were needing a change, and the problems with the Jadis came in the good moment! I understand it, for me this hobby is also very dynamic. :eek: