Judgement: (evaluation)
The Dilemma:
Coursework due for completion in 7 days time.
Considerations:
Time needed to complete project - more than I've got
Time available to complete project - not enough
Decision: (course of action)
Establish requirements and expectations:
Group project - organisation of overall project - check
organisation of individual input - check
time line - (anal I know) - check
inclusion without exclusion - check
Conclusion 1: A perfect world would have seen me, today, polishing my coursework ready to hand in, but Sods Law ("what can go wrong, will go wrong") has been in play and instead I am just starting. The main impedement to making a start, the requirements and expectations, has now been clarified and some order has been restored. Allowing a second process to begin:
Judgement:
Remains the same
Decision:
Do some work!
Conclusion 2: Thats simple then, all sorted! If only it was that simple, the situation remains the same but yet more decisions need to be made...what questions to answer? what approach to take? when to work on this component and when to work on others? When to 'fit' study into the rest of my life? and so on.
I use this example to illustrate the complexity of decision making in everyday life. This example is one of many processes of decision making that I need to attend to just today, regarding one component of my study which is one aspect of my life. I'm fairly certain that this situation is not uncommon to anyone reading this, it is hardly surprising then that I use 'generalisations' of information available to me in order to make decisions and worry about the bias and errors later (if they have any impact).
This example is realtively simple to analyse and reduce to individual components of effect. Decisions made in the first instance effect future decisions about the dilemma and may even reformulate the judgement. The concept that judgements and decisions are made in isolation of each other is sterile and life is usually anything but sterile. This is why, in my opinion, simulated predictions of behaviour fail to predict actual behaviour. Simulations rarely take into account the rich tapestry of individual differences, biases and most importantly errors. Is this a bad thing? I think not.
Saturday, 13 November 2010
Monday, 8 November 2010
Judgement without the math...heuristics
My trusty Chambers defines an heuristic as:
serving or leading to find out: depending on assumptions based on past experience: consisting of guided trial and error (from the Greek, eureka - to find)
This sounds far more promising as a theory of how we make judgements on a day to day basis, I'm fairly certain I'm not the only person that doesn't see themselves as working through mathematical formulae in order to work out the probability of an event occurring...basically I take a guess, hopefully and educated guess, based on what has gone before in my knowledge/experience. That is my judgement is subjective.
That's the basics of it, but as expected not the end of it. There isn't one type of heuristic, there are different shortcuts from A to B depending on where and what A and B are and what my subjective fallibility's are as the judgement maker.
The representative heuristic, described by Gilovich and Savitsky as "like goes with like" is one we are all guilty of. That is, making a judgement based on the comparison of the similarity of the current focus with past experience, stereotypes are a great basis for comparison here. This heuristic has been used to explain many judgement phenomena (why we don't use math). As a consequence of our reliance on this heuristic "dubious cause-effect links are uncritically accepted because they satisfy the principle of like goes with like" (Gilvich T. & Savitsky K., 2002)
The Hot Hand in basketball is such a phenomena. A player is said to have the 'hot hand' when he has hit the basket on a previous shot; in the eyes of the player and fan he is therefore more likely to hit the next shot than miss it. Gilovich et al (1985) tested this phenomena in a variety of ways, concluding that there was "no evidence of positive correlation between the outcomes of shots" (p 295). But fans believe it to be true as do players themselves and it even influences team selection and the number of times a player is selected in a shooting role, what causes this? Gilivich et al suggest it is due to the misperception of random sequences, arguing that hits and misses are random events and a shooting streak is no more likely to happen than a missing streak, thus they write off the 'hot hand' as a costly fallacy. Interestingly Burns suggests that belief in the hot hand may be "an effective, fast and frugal heuristic" for the benefit of the team. He posits that in a game situation such an heuristic is necessary due to time constraints that is, players are unlikely to do the probability calculation to determine the optimum result. I discussed this with my daughter who plays National level basketball; her view was that team selection is based upon shooting averages and shots in a game situation are allocated to the player who is most "on form" that is who's had the most hits recently. I have to agree with Burns...ok so the hot hand is a load of baloney when it comes to actual probability but it works on court. I would also counter, and was pleased to see that Gilovich does make reference to this, that shooting in basketball is a skill that players spend hours perfecting in as many different scenarios as they can, after all the whole point of a game is to see who is the better team based on the number of baskets they sink. One would expect then that players should have a higher than 'random' chance of hits than misses.
The availability heuristic is used in judgements of frequency and another possible explanation of the hot hand phenomenon, although it is most oft cited as an example of representativeness. This heuristic refers to the likelihood of an event by how easily it comes to mind; with regard to the hot hand I am more likely to remember the outcome of the last few shots a player has taken and base my prediction outcome of his next shot on previous experience. This information is far more readily retrieved (particularly with respect to time constraints, basketball being the 2nd fastest team game after ice hockey) and I judge the players overall ability on a small number of events (streak). This bias suggests that more readily available instances are perceived as more numerous; the player with the hot hand has hit the last few baskets so, according to this heuristic, as the recent information is more readily available I perceive the number of hits to be larger than they actually are and ascribe to the player a more than 'random' prediction of a hit.
Alexander Pope wrote "to err is human..." and yes, using heuristics leads to all sorts of biases and errors, but it is who and what we are. We thrive on 'unpredictability'; in sports and gambling, for example, I would go so far as to say it is a cornerstone, in fact 'absolute prediction' (using a computer for example) is 'cheating' in the gambling world. However accuracy is essential in an economic environment, and a lack of is disastrous. There are occasions when heuristics are the only available option, when time or knowledge is lacking. In other words there is a time and place for heuristics and most of us rely on this 'quick' method of judgement making on a daily basis.
serving or leading to find out: depending on assumptions based on past experience: consisting of guided trial and error (from the Greek, eureka - to find)
This sounds far more promising as a theory of how we make judgements on a day to day basis, I'm fairly certain I'm not the only person that doesn't see themselves as working through mathematical formulae in order to work out the probability of an event occurring...basically I take a guess, hopefully and educated guess, based on what has gone before in my knowledge/experience. That is my judgement is subjective.
That's the basics of it, but as expected not the end of it. There isn't one type of heuristic, there are different shortcuts from A to B depending on where and what A and B are and what my subjective fallibility's are as the judgement maker.
The representative heuristic, described by Gilovich and Savitsky as "like goes with like" is one we are all guilty of. That is, making a judgement based on the comparison of the similarity of the current focus with past experience, stereotypes are a great basis for comparison here. This heuristic has been used to explain many judgement phenomena (why we don't use math). As a consequence of our reliance on this heuristic "dubious cause-effect links are uncritically accepted because they satisfy the principle of like goes with like" (Gilvich T. & Savitsky K., 2002)
The Hot Hand in basketball is such a phenomena. A player is said to have the 'hot hand' when he has hit the basket on a previous shot; in the eyes of the player and fan he is therefore more likely to hit the next shot than miss it. Gilovich et al (1985) tested this phenomena in a variety of ways, concluding that there was "no evidence of positive correlation between the outcomes of shots" (p 295). But fans believe it to be true as do players themselves and it even influences team selection and the number of times a player is selected in a shooting role, what causes this? Gilivich et al suggest it is due to the misperception of random sequences, arguing that hits and misses are random events and a shooting streak is no more likely to happen than a missing streak, thus they write off the 'hot hand' as a costly fallacy. Interestingly Burns suggests that belief in the hot hand may be "an effective, fast and frugal heuristic" for the benefit of the team. He posits that in a game situation such an heuristic is necessary due to time constraints that is, players are unlikely to do the probability calculation to determine the optimum result. I discussed this with my daughter who plays National level basketball; her view was that team selection is based upon shooting averages and shots in a game situation are allocated to the player who is most "on form" that is who's had the most hits recently. I have to agree with Burns...ok so the hot hand is a load of baloney when it comes to actual probability but it works on court. I would also counter, and was pleased to see that Gilovich does make reference to this, that shooting in basketball is a skill that players spend hours perfecting in as many different scenarios as they can, after all the whole point of a game is to see who is the better team based on the number of baskets they sink. One would expect then that players should have a higher than 'random' chance of hits than misses.
The availability heuristic is used in judgements of frequency and another possible explanation of the hot hand phenomenon, although it is most oft cited as an example of representativeness. This heuristic refers to the likelihood of an event by how easily it comes to mind; with regard to the hot hand I am more likely to remember the outcome of the last few shots a player has taken and base my prediction outcome of his next shot on previous experience. This information is far more readily retrieved (particularly with respect to time constraints, basketball being the 2nd fastest team game after ice hockey) and I judge the players overall ability on a small number of events (streak). This bias suggests that more readily available instances are perceived as more numerous; the player with the hot hand has hit the last few baskets so, according to this heuristic, as the recent information is more readily available I perceive the number of hits to be larger than they actually are and ascribe to the player a more than 'random' prediction of a hit.
Alexander Pope wrote "to err is human..." and yes, using heuristics leads to all sorts of biases and errors, but it is who and what we are. We thrive on 'unpredictability'; in sports and gambling, for example, I would go so far as to say it is a cornerstone, in fact 'absolute prediction' (using a computer for example) is 'cheating' in the gambling world. However accuracy is essential in an economic environment, and a lack of is disastrous. There are occasions when heuristics are the only available option, when time or knowledge is lacking. In other words there is a time and place for heuristics and most of us rely on this 'quick' method of judgement making on a daily basis.
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