Why Flip A Coin? The Art and Science of Good Decisions
By Harold Warren Lewis
Reviewed by Patrick Scott
Introduction
Have you ever thought that flipping a coin is the best way to make a decision? Maybe in the case of what
team starts a soccer game, but depending on the flip on a coin to make everyday decisions could lead to
utter disaster. Imagine how far we would get, if our government flipped a coin to approve a new bill.
Debates among members of the government would be useless, as their opinions would not count in the long
run. All bills would have a fifty-percent chance of passing and a fifty-percent choice of not passing.
Should more money be put into health care? Just flip a coin…
Fortunately, the world that we live in is not as it is mentioned above. Much more thought and debate goes
into the final decision of whether or not a bill should pass. Why Flip A Coin? The Art and Science of Good
Decisions puts forward many ideas on how we, as individuals and society, can make better decisions. It
does not propose a solution to any problem, however it brings forth many concepts that we should take into
consideration while making decisions.
Well thought out decisions will most likely result in a much better decision. However, the time (and
possibly costs) to achieve this optimal decision may be infeasible. Through our study of Decision Support
Systems, we know that they are built to help the decision maker in making a decision. What many of us
take for granite when using a DSS, is that some poor developers wrote this code to provide you with
decision support. Guess where they got their ideas from to write the code that is the engine behind the
system? It didn’t come from the sky, nor did the source code jump out of the textbook and into the system.
The ideas came from the heads of many individuals. Probability, ranking, preferences, apportionment, and
fluctuations are just few of the many ideas that the book discusses that are important to the creation a DSS.
Overview of Book
While the book proposed many ideas that go into decision making, it was more directed to stimulate the
reader’s mind, rather than be used by those who develop Decision Support Systems. To support that ideas
brought forward, H. W. Lewis uses many examples to illustrate why these concepts are important to the
decision making process. Even though many of the examples that he used for topics such as apportionment
and voting are based on life in America, it was easy to relate them back to the topic at hand.
One example that is used throughout the book, which does not reflect the lifestyle of Americans in general,
is the dating game. The dating games consists of one person with a pool of a hundred possible suitors, and
how that one person is suppose to decide on who they wish to pursue a life with. This example relates to
decision making in many different ways, including probability that this individual will choose the perfect
mate out of the pool of potential candidates, the individual’s preference or ranking of the suitors and
gambling on the unknown.
The author looks into many issues concerning each idea, given his opinion even if it does not follow the
opinion of everybody else. He discusses the situations where we would benefit from using one method of
decision making to another, such as a democratic society versus a dictatorship. Believe it or not,
dictatorships (though I do not promote them in anyway), do have benefits when it comes to decision
making. I am sure there are many people out there who disagree with the concept of dictatorship, but the
power they would hold while in such a position would be hard to turn down. Bossy people, in general, are
dictators. The benefits however are that decisions that may benefit society as a whole can be passed
quickly as opposed to a democratic society where you can guarantee that there will be heated debate
amongst the political parties. The disadvantage, on the other hand, outweighs that advantage by a long
shot. Decisions are made with discussing what society wants, which means the dictator may be the only
person that benefits from his decision. In a “perfect” democracy, all decisions would be made in the best
interest of the public.
What I Learned From the Book
Reading this book broadened my knowledge on the concepts that go into decision making. I am now very
aware that most decisions we make are based on a combination of many factors. Even though it may seem
like you have put little thought into making an everyday decision, your brain is factoring in all the relevant
information you have been given and comes up with an answer that is close to being relevant as you are
going to get. On a subconscious level our brain works with probabilities, rankings, and the possible results
from our final decision, to come up with a final solution.
Throughout the book, the concept of probability was discussed and how it is relevant to a specific type of
decision making. Probability can be used for all sorts of problems, such as pouring quarters into a slot
machine or determining if you have found your “perfect” mate. We all know that flipping a coin, we will
either end up with a head or a tail. We have a fifty-percent probability of each happening. However, life is
not usually that simple and more statistical models come into play to determine the probability of a
situation happening. Sometimes though, probability really doesn’t matter at all. We either want to know if
the situation is going to happen or not. For instance, if I seismologist said that there is a thirty-percent
chance that we will suffer an earthquake in the next month, that is not what we really care about. We want
to know if there is going to be an earthquake in the next month, or if we can live in peace. By the way,
seismologists still can not predict earthquakes but it works as a good example.
One chapter was dedicated toward apportionment, the division of power while keeping representation by
population. The example given in the book talks about the 485 seats in the United States House of
Representatives, however, here in Canada we follow the same procedure. At the federal level, division is
power is broken up by province first and then by population. Because of the population of New Brunswick
compare to that of Ontario, New Brunswick only has a fraction of the seats that Ontario does in the House
of Commons. However, it makes sense, otherwise New Brunswick would have just as much voting power
as Ontario, even though the population of New Brunswick is outnumbered by the number of people living
in the greater Ottawa region. Apportionment minimizes
Relevance to Decision Support Systems
The book did not discuss decision support systems at all, however, it mentions many of the underlying
concepts that are put into each and every decision support system that is implemented today. Decision
support systems mainly work with probabilistic models, ranking models, and the uncertainty that lies in the
future. Not even the models are discussed in this book, just the theory behind their relevance to decision
making. However I feel that knowing the concepts behind what the actual models are built on, gives us a
better understanding of how a decision support system works. They are meant to give us the best possible
decision depending on all relevant information that they are given. Humans can do the same thing,
however, it would take them much longer to come up with the optimal decision, and they may not have
taken all possible decisions into consideration.
Conclusion
Overall, the book in general gives the reader a good background in the theories and models that are used in
the development of a decision support system. Even though most of the concepts that are mentioned are
more or less basic, their relevance to the subject of decision support system cannot be ignored.
Did you know that slot machines pay back between ninety and ninety-seven percent of all the money that
they take in? The numbers may seem really high, but the odds are still against you leaving the casino with
extra cash in your pocket. If you go to a casino expecting to double your money, do you know the best way
to do this? Using probability, you should bet everything in a double-or-nothing game. Simple as that!
Enter the casino one minute, walk out five minutes later with double the money. The probability of this is
still low, but it is your best chance at doubling your money. Casinos are full of decisions, however, the
most beneficial decision according to the author is not even entering the doors of the casino.
The book expands our knowledge of the way we think about decision making. A day will not go by that
we will not have to make any decisions. Everyday is full of decisions, and making the best ones is what we
try to achieve. This book gives the reader the foundation for making good decisions, no matter what the
case.