Problem Determination Theory Methods Advice from Sherlock Holmes

Problem Determination Theory & Methods Advice from Sherlock Holmes Compiled by Brian Clark Delivered to the John Openshaw Society of Houston, Texas USA on 26 th November 2014

“I know my dear Watson, that you share my love all that is bizarre and outside the conventions and humdrum routine of everyday life. ” [HOUN]

“It is a capital mistake to theorize before you have all the evidence. It biases the judgment. ” [STUD] “It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. ” [SCAN]

“Data!” he cried impatiently. “I can't make bricks without clay. ” [COPP]

“I am glad of all details, whether they seem to you to be relevant or not. ” [COPP]

“There is no part of the body which varies so much as the human ear. ” [CARD]

“There is nothing like first-hand evidence. ” [STUD]

“There is no branch of detective science which is so important and so much neglected as the art of tracing footsteps. ” [STUD]

“The observer who has thoroughly understood one link in a series of incidents, should be able accurately to state all the other ones, both before and after. ” [FIVE] “What one man can invent another can discover. ” [DANC]

“Not invisible but unnoticed, Watson. You did not know where to look, and so you missed all that was important. ” [IDEN]

“You see, but you do not observe. The distinction is clear. ” [SCAN] “On the contrary, Watson, you can see everything. You fail, however, to reason from what you see. You are too timid in drawing your inferences. ” [BLUE]

“‘Pon my word, Watson, you are coming along wonderfully. You have really done very well indeed. It is true that you have missed everything of importance, but you have hit upon the method, and you have a quick eye for colour. Never trust to general impressions, my boy, but concentrate yourself upon details. ” [IDEN]

“You know my method. It is founded upon the observation of trifles. ” [BOSC] “It is, of course, a trifle, but there is nothing so important as trifles. ” [TWIS]

“It has long been an axiom of mine that the little things are infinitely the most important. ” [IDEN] “I am an omnivorous reader with a strangely retentive memory for trifles. ” [LION]

“A man should keep his little brain attic stocked with all the furniture that he is likely to use, and the rest he can put away in the lumber-room of his library where he can get it if he wants it. ” [FIVE]

“It was easier to know it that to explain why I know it. If you were asked to prove that two and two made four, you might find some difficulty, and yet you are quite sure of the fact. ” [STUD]

“Singularity is almost invariably a clue. The more featureless and commonplace a crime is, the more difficult it is to bring it home. ” [BOSC] “We must look for consistency. Where there is want of it we must suspect deception. ” [THOR]

“It is of the highest importance in the art of detection to be able to recognize out of a number of facts which are incidental and which vital. Otherwise your energy and attention must be dissipated instead of being concentrated. ” [REIG]

“Having gathered these facts, Watson, I smoked several pipes over them, trying to separate those which were crucial from others which were merely incidental. ” [CROO]

“Nothing clears up a case so much as stating it to another person. ” [SILV]

“Hopkins has called me in seven times, and on each occasion his summons has been entirely justified. ” [ABBE] “I wonder how a battery feels when it pours electricity into a non-conductor. ” [DYIN]

“Let us get a firm grip of the very little which we do know, so that when fresh facts arise we may be ready to fit them into their places. ” [DEVI]

“Circumstantial evidence is a very tricky thing. It may seem to point very straight to one thing, but if you shift your own point of view a little, you may find it pointing in an equally uncompromising manner to something entirely different. ” [BOSC]

“In solving a problem of this sort, the grand thing is to be able to reason backwards. That is a very useful accomplishment, and a very easy one, but people do not practice it much. In the everyday affairs of life it is more useful to reason forward, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically. ” [STUD]

“We balance probabilities and choose the most likely. It is the scientific use of the imagination. ” [HOUN]

“When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth. ” [BLAN]

“Eliminate all other factors, and the one which remains must be the truth. ” “How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? ” [SIGN]

“Improbable as it is, all other explanations are more improbable still. ” [SILV] “It is impossible as I state it, and therefore I must in some respect have stated it wrong. ” [PRIO]

“It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. ” [BERY] “We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth. ” [BRUC]

“They say that genius is an infinite capacity for taking pains. It’s a very bad definition, but it does apply to detective work. ” [STUD]

“You know that a conjurer gets no credit when once he has explained his trick; and if I show you too much of my method of working, you will come to the conclusion that I am a very ordinary individual after all. ” [STUD]

“Watson here will tell you that I never can resist a touch of the dramatic. ” [NAVA]

“I am afraid that my explanation may disillusion you, but it has always been my habit to hide none of my methods, either from my friend Watson or from anyone who might take an intelligent interest in them. ” [REIG]

“The theories which I have expressed, and which appear to you to be so chimerical, are really extremely practical – so practical that I depend upon them for my bread and cheese. ” [STUD]

“I play the game for the game’s own sake. ” [BRUC] “Chance has put in our way a most singular and whimsical problem, and its solution is its own reward. ” [BLUE]

“There is nothing more stimulating than a case where everything goes against you. ” [HOUN]

“Come, Watson, come! The game is afoot. Not a word! Into your clothes and come!” [ABBE]

The End

text [book]