The following post is one of a small group of posts I have written over the past 13 years that have attracted the most readers. It originally appeared in 2010. I have revised and updated it.
Over the next month or so, I will revise other posts that have drawn the most viewers.
What’s the difference between sending a rocket to the moon and getting children to succeed in school? What’s the difference between a surgeon extracting a brain tumor and judge and jury deciding guilt or innocence for a person accused of murder?
Answers: sending a rocket to the moon and surgeons extracting brain tumors are complicated tasks while getting children to succeed in school (or, for that matter, raising a child) and navigating the criminal justice system are complex.
According to York University (Ontario, Canada) business professor Brenda Zimmerman, complicated procedures like brain surgery and rocket launchings require engineer-designed blueprints, step-by-step algorithms, well-trained staff, and exquisite combinations of computer software running carefully calibrated equipment. Think rocket landing on the moon in 1969, doctor-controlled robotic arms doing brain surgery, and the U.S. “shock and awe” invasion of Iraq in 2003.
A complicated system assumes expert and rational leaders, top-down planning, smooth implementation of policies, and a clock-like organization that runs efficiently and effectively. Work is specified and delegated to particular units. Here, for example, is a 2021 flow chart school officials in Amphitheater Unified District (Tucson Arizona) are expected to use in deciding whether or not students who returned to school were sick.
Certainty about outcomes is in the air the organization breathes. Complicated systems use the most sophisticated math, technical, and engineering expertise in mapping out flow charts to solve problems.
Yet even those sophisticated systems fail from time to time such as the Challenger shuttle disaster, Three Mile Island nuclear meltdown, the 2010 BP oil leak, and the U.S. ‘s National Security Agency inability to detect cyber espionage by Russia in 2021.
Complex systems like criminal justice, health care, and schools, however, are filled with hundreds of moving parts, scores of players of varied expertise and independence yet missing a “mission control” that runs all these different parts within an ever-changing political, economic, and societal environment. The result: constant adaptations in design and action. Recall the U.S. President, Congress, lobbying groups, and scores of interest groups trying to get a reform health care bill into law during 2010 in the midst of a slow recovery from the quasi-Great Depression of 2008. Or consider how the Covid-19 virus closed down large and small businesses, urban and suburban schools, and federal and state courts for months
Blueprints, technical experts, strategic plans and savvy managers simply are inadequate to get complex systems with thousands of reciprocal ties between people to operate effectively in such constantly changing and unpredictable environments. These web-like complex systems of interdependent units adapt continuously to turbulent surroundings. See the complexity of the U.S. and other countries dealing with the Taliban in Afghanistan in this slide.
Or consider how the criminal justice system to avoid gridlock created plea bargains. Interdependent parts of the system (police, defense lawyers, district attorneys, and judges) adapted to overflowing court dockets.
Health care, criminal justice, and school systems even with their façades of command-and-control mechanisms, policy manuals filled with procedures for subordinates to follow are constantly buffeted by unpredictable events—picture a hospital emergency room, a kindergarten class of wailing and reclusive 5 year-olds, and judges doing arraignments one after the other.
So what if schools, hospitals, and courts resemble spider webs of interconnecting strands than carefully designed and well-oiled machines?
One practical outcome of this distinction is approaching planned change differently. Those who run complicated systems (e.g., airplane and automotive industrialists, investment bankers, computer hardware and software CEOs) introduce change by laying out a detailed design of what is to be changed, step-by-step procedures to implement the change and overcome any employee resistance, and reduce variation in performance once change is implemented. Highly rational, mechanical, and smooth.
The problem for those who inhabit complex systems like schools is that change, conflict, and unplanned changes occur all the time. So do adaptations because of the web-like independent and interdependent relationships that make up the system.
But what happens when smart people try to graft procedures from complicated organizations onto complex systems?
Trying to toilet train a 3-week old baby is an absurd example of the thinking that occurs when a complicated solution (designing a flow chart for teaching toilet training) meets a complex problem (a baby that feeds continually, sleeps 20 hours a day, and soils her diapers repeatedly). Inevitably, the toilet training flow chart gets adapted again and again until the baby is ready to be toilet trained—a year or more later. Or consider a less absurd example of the pay-for-performance plans imported from complicated business systems to be installed in complex school districts. Such policies will get adapted repeatedly and, over time, will become unrecognizable to both designers and administrators.
So what? You have made the distinction between complicated and complex, Larry, but what is the significance in the difference between complicated and complex? The answer to the so-what question is: At the minimum, reform-minded policymakers need to know that working in a complex system means adapting to changes, dealing with conflicts, and constant learning. These are natural events, not aberrations. Know further that reform designs borrowed from complicated systems and imposed from the top in complex systems such as schooling will hardly make a dent in the daily work of teachers whose job is convert policy into action.
Larry Cuban on School Reform and Classroom Practice 
