Noise: A Flaw in Human
Judgment
By:
Daniel Kahneman, Olivier Sibony, and Cass R.
Sunstein
Reviewed by
Geoffrey W. Sutton
We are constantly
exposed to opinions. Some of those opinions are judgments. And some of those
judgments affect our opportunities to work, obtain healthcare, receive fair
treatment by government entities, and earn fair evaluations in school. Some
people are paid to make informed judgments. Unfortunately, some judgments are
noisy—they vary. Noise is about the differences in judgments that affect our
lives.
When the
authors provide examples of variation in judgments, they are writing about
variability in a statistical sense. As a retired professor who taught research
and statistics to undergraduate and graduate students, I’m not sure the authors
were entirely clear—at least not clear enough for readers who are either new to
the concept or haven’t drawn on their statistics knowledge for some years. In
any event, I think the book deserves a look because it draws attention to a
real problem—a problem with which I’m familiar.
The authors
often provide examples of judges in the criminal justice system. For example,
they note that judges can vary in the length of a sentence for the same offence.
They also provide examples of different diagnoses provided by physicians for
the same set of symptoms—this is especially true in the diagnosis of mental
disorders.
The authors
introduce the problem of variation in judgments by referring to shots at target.
Given a group of people firing at a target, there will likely be some
variation. If they are experienced, we would expect them to be close to the
bullseye. The degree to which the holes are scattered is variance. The
variation is like noise in judgments, which deviate from accuracy. Those
deviations represent error.
Let me
suggest dropping the term variance in judgments in favor of differences. We can
expect people to have differences of opinions about one thing or another but
when it comes to a medical diagnosis, we want an accurate decision. When
different experts arrive at different diagnoses, that’s noise. And that can be
scary when the diagnosis leads to very different types of treatment.
Bias is a
related concept. Bias is a systematic type of error. Using the target analogy,
bias reveals a tendency for all the deviations from the bullseye to be located
in the same area. In psychology, it might be a tendency for some clinicians to
diagnose anxiety rather than ADHD or ADHD rather than anxiety when observing fidgety
children. Bias can be found in numerical scores too such as when some
psychologists tend to obtain lower scores than others on intelligence tests.
The authors
also cover the problem of transient differences or occasion noise. That’s the
kind of inconsistency that can happen when the same person looks at the same
data but comes up with a different judgment on two different occasions. The
authors mention some well known influences like time of day and hunger
affecting judgments.
I’ll skip
ahead to their recommendations. After providing us with additional terms and
many examples, the authors offer suggestions for controlling unwanted noise.
One major suggestion is to rely on algorithms based on the evidence that computerized
assessment of all relevant data can often beat human decision-makers in
accuracy. The authors recognize this won’t sell well to a lot of readers but
they do offer a defense against common objections.
A second,
and in my mind more palatable approach is to create a structured approach to
decision-making. This can be as simple as guidelines, checklists, and preset
questions to use in various fields. In applied psychology and counseling,
students learn to use checklists and decision trees when making a diagnosis.
Others learn to use scales and questionnaires and ways to aggregate available
information relevant to both diagnoses and treatment plans.
There’s a
lot more in this book both in terms of examples of noise as well as suggestions
for reducing noise in different areas of life. They supplement their work with
useful appendixes: How to conduct a noise audit, A checklist for a decision
observer, correcting predictions.
Reference
Kahneman,
D., Sibony, O., & Sunstein, C.R. (2021). Noise: A flaw in human judgment. New
York: Hatchette.
and see my books on AMAZON or GOOGLE
STORE
Also,
consider connecting with me on FACEBOOK Geoff W. Sutton
TWITTER @Geoff.W.Sutton
You can read many published articles at no charge:
Academia Geoff W Sutton ResearchGate
Geoffrey
W Sutton
Comments
Post a Comment