Great BA fallacies #3 - Begging the question

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Submitted by GuyBeauchamp on Mon, 2008-12-01 03:49.

This fallacy creeps in just when you don't expect it - and I should know: I've been right about every other fallacy so I'm right about this one!

And there is the fallacy: I assume that because I've been right every time before (please remember that this is a made up example before reminding me of all my mistakes!) that I will be right in the future.

It's like saying that because I have flipped a coin 3 times and it has come up heads each time that the next time must be tails. No - each time I flip it there is a 50:50 chance of it being heads regardless of what happened on the last 3 or 5 or 100 flips.

Past performance is no indicator of future performance. Such reasoning that assumes an outcome in order to justify the outcome is begging the question.

Here's a classic BA example of it: "we tried that before and it didn't work". The inference is that because we tried it before and it didn't work if we try it again it won't work. The truth of the outcome will be determined by why it didn't work before and whether those factors still apply.

This fallacy ties in nicely with fallacy #1 - argument from authority - just because some 'authority' says something does not make it true: don't just believe someone because they have a reputation for being right or knowing a lot about something, that would beg the question of whether they are right in this case as well. You may want to use the person's track record as evidence that their opinion is worth considering - but it is NOT evidence that they are right.

Sometimes I get asked about how to Project Manage a project I am doing the analysis on: "you're doing a good job on the analysis so how should we restructure the project plan". I don't know! Project Management is a separate skill set I don't possess - asking me on the basis I am doing well with the analysis maybe flattering but would still result in (very probbaly) the wrong answer, so it is in both our interests for me to declare that.

Begging the question - assuming that we know the answer before asking the question and basing our answer on that false assumption - it gets everywhere and it always has caused trouble so it always will!

Whoops...

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Beggining the question

Submitted by Peter Aveyard (not verified) on Tue, 2008-12-02 04:58. *

Very entertaining and spot on.

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on the edge

Submitted by MaryC on Tue, 2008-12-02 07:48. *

I think you are on the edge of a philosophical discussion about the meaning of knowledge here. Your basic thesis is that the past does not predict the future - but the whole point of gathering requirements from users is that their perception of their needs to be addressed or the project will fail, and the best understanding of their needs comes from asking them what they know about, ie what has happened in the past!

Also, looking at your example:

"It's like saying that because I have flipped a coin 3 times and it has come up heads each time that the next time must be tails. No - each time I flip it there is a 50:50 chance of it being heads regardless of what happened on the last 3 or 5 or 100 flips. "

You don't actually know if there is a 50:50 chance or not. It could be that the coin is weighted, or has heads printed on both sides, or is always flipped from a certain way for cultural reasons. It could even be that the answer "is" always heads because saying anything else would dishonour the king, no matter what the coin shows.

Basic statistics tells you that a sample size of three won't give you an accurate prediction of future behavour. But if you flipped it 300 times, and it still came up heads every time, you can be fairly certain what will happen next time.

That doesn't mean you don't ask "what happens if it's tails" - but you also need to ask "do the usual rules apply if it's tails?"

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re: On the edge

Submitted by GuyBeauchamp on Tue, 2008-12-02 08:06. *

Thanks MaryC for your comment.

I take your point entirely about the coin being weighted etc. As a BA I would certainly want to know if it was weighted (I would want to know about all the relevant conditions) - but for a weighted coin then the thing that predicts the behaviour of the coin is not its past behaviour, but its weighting! I could take that same coin and flick it in zero gravity and get different results and so on...the point is that past behaviour still fails to be a reliable sole predictor...

The other point I'd like to raise is that my basic thesis is that as BAs we should be aware of the fallacy of using the conclusion of an argument as a justification for an arguement (by either a user or us) - hence my final (flippant) comment: "Assuming that we know the answer before asking the question and basing our answer on that false assumption - it gets everywhere and it has always caused trouble so it always will!

Whoops..."

www.smart-ba.com

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Learning from History

Submitted by kmatthews on Fri, 2008-12-05 06:53. *

I do not agree with your reasoning, except in the extreme example, and possibly in the statistical examples which do not depend on human involvement.

By the extreme example I mean with 100% surety, obviously I cannot say with 100% surety that something will be the result based on previous experience as that would mean I could predict the future, but I can get pretty damn close!

I can say that based on past experience if I jump off a 30 story building onto a concrete roadway, without a parachute (or any other means of slowing my decent) and without any protective devices then I will most probably 99.99% sure be killed. Are there examples of survival probably, but I can be pretty damn sure it would be a miracle.

I can say that based on experience if I punch a big hole in a ship below the waterline in the middle of the Atlantic ocean there is a great possibility it will sink.

I can say that, based on history, attempting to invade Russian in the middle of winter with a land army will probably not result in success. Ask Napolean, Hitler and a few others that tried it. (My History teacher in an attempt to justify his existence always used to say "We can all learn from History" Zzzzzzzz)

I can say that if I got into a boxing match with the world heavyweight champion that I would probably lose, as would most others for that matter, but maybe not all.

So I guess I disagree with the definitive “Past performance is NO indicator of future performance” I would say that past performance can be a strong indicator of future performance give similar circumstances, but future performance cannot be 100% guaranteed based on past performance.

Statistically (and I am in no way a statistician) if you kept flipping your coin (assuming it was a regular two sided coin) and it kept coming up heads, then almost all gamblers in the world would be more and more prepared to bet next time it would be tails! Even if it always has a 50:50 chance of being heads over any large sample of flips it is likely that 50% of the time it will be tails.

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re: "Learning from history"

Submitted by GuyBeauchamp on Fri, 2008-12-05 10:34. *

Thanks for your comment Kmathews.

Basically I sort of agree with you.

I think I am guilty of using a poor example to illustrate "begging the question".

The principle behind the "begging the question" fallacy is to use an assumption of the outcome as a justification that it WILL be the outcome. Example: "assuming that we know the answer before asking the question and basing our answer on that false assumption - it gets everywhere and it always has caused trouble so it always will!"

And there is also the matter of causality: the fact that every time I jump off a high building I die does not CAUSE my death, gravity causes my death not the fact that every time I do it I die. So I can not rationally say because every time I jump off I will die, that this time I jump off I will die. That is why there are exceptions such as if there were a window clearners platform in the way of my fall which in effect thwarts gravity (the real culprit).

Instead it would be (more?) true to say every time I am accelerated at 32 feet per second per second in to a hard surface over a space of 100 feet I die.

Same arguement applies with the flipping coin I think...

www.smart-ba.com

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On the edge

Submitted by leannedan on Tue, 2008-12-02 11:35. *

I seldom assume I know the answer - am I that different from other BA's? I thought lawyers were the ones who weren't supposed to ask a question if they didn't already know the answer (and even that only holds true in court).

I've heard the saying "past performance predicts future behavior." Where this discussion is concerned I would have to say that I don't view that as a means of justifying an outcome, but recognizing a reality. Just because something failed in the past does NOT mean that it will fail in the future.

The problem is that even when we identify the reason/behavior for the failure, it is very difficult to get people to change their behavior to make something succeed. I tend to find myself recognizing the behavior that is the problem and changing events to accomodate the behavior so that success can be achieved.

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re: On the edge II

Submitted by GuyBeauchamp on Tue, 2008-12-02 12:04. *

Thanks Leannedan for your comment.

It's interesting you have heard the phrase "past performance predicts future behavior." - so have I...but look at the small print for all those invest in a company/portfolio adverts and you will see the phrase "past performance does not indicate future performance"! And certainly logicians will tell you the same.

So I agree entirely with your statement concerning reality: "Just because something failed in the past does NOT mean that it will fail in the future" - as MaryC pointed out there can be all kinds of reasons to explain past performance...

It is kind of easy sometimes to justify a conclusion to a question based on what we think we already know. I have seen loads of BAs do this so it must be true.

And that phrase "I have seen loads of BAs do this so it must be true" is an example of how easy it is to do it! It does not follow that it is true whether or not I have seen loads of BAs do it...

www.smart-ba.com

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humor in extreme examples

Submitted by spgrc on Mon, 2008-12-08 19:37. *

You have to chuckle at the extreme examples to justify a position.

I have to side with Guy on this one. Predicting the results or outcome on historical outcome can be misleading. There is an oxymoron saying that I've heard that rings true to me... that is "see it again for the first time". It is human behaviour to jump to conclusions, outcome or results. We use our senses, emotions and experiences to develop truths.

I think what Guy - humourously - is saying is that focus or study should be emphasized on the attributes or characteristics of the historical outcome not necessarily the historical outcome itself. If the attributes or characteristics remain the same under the current environment or conditions for the problem to be solved, then it is likely that the outcome will be the same. As our cognitive ability is wired to gloss over rudimentary details that may be relevent to the outcome, it is sometimes worth while to challenge our truths to look at something again as if it has never been seen before or without bias.

Scientific exploration does this continuously and thank goodness as without this we would still think the world is flat.

- Ron

www.canatasia.com

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re: Humour in extreme examples

Submitted by GuyBeauchamp on Wed, 2008-12-10 03:33. *

Ron,

Thanks for that assessment.

Your last point about scientific exploration is stunningly well made and I could not agree more: science proceeds on the basis of justified rational arguments built on extrapolations from observations about the world around us - its mission is to uncover new facts. Business Analysis has a mission to 'uncover' new change requirements and has no objective reality to start from, apart from that it should proceed on the same basis of justified arguments that science does applying the same level of rigour to the construction of the arguments. BA reality comes from what killer stakeholders define and off we go - see this post that contrasts scientific method and business analysis methods.

www.smart-ba.com

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Past to predict current outcomes

Submitted by jim4004 on Tue, 2008-12-09 10:54. *

Nobody has the complete picture of business or it's processes. Each person has only a small slice of the picture. Nearly all processes change with time. I always test my requirements for accurate inputs to produce the expected results. In the old days, we used data flow diagrams to do this; but the concept is the same. If you have a process that produces something, test the requirements to make sure you've identified the parts that are required to produce it. If you were to find that automating a process didn't work previously, and you're being asked to do it again. It's most likely because there is a business need to do it, and the failure has caused more problems for the business. Most requirements failures are because of invalid assumptions. Complex projects frequently fail because of too much crammed into one big release. Approach is very important. The advantage of a second try of a failed project, is you know more of the risks than you knew before. Alexander Graham Bell failed hundreds of times before creating the telephone, but each failure was information for the next attempt.

The best way to avoid the trap of doing the same thing over and over again, is to network with other professionals. Learn how they do things, and what works for them. When I obtained my CBAP, I attended study groups and shared my thoughts on JAD sessions. I thought they weren't very valuable bacause the Type A personality always gives the most requirements. Other study group members told me how they handle that, to prevent that from happening. It changed my view of Jad sessions.

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Great BA fallacies #3 - Begging the question

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Beggining the question

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Learning from History

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On the edge

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humor in extreme examples

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Past to predict current outcomes

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