'Hindsight bias' could hide real lessons of Columbia accident report

By PAM FROST GORDER, Research Communications

A psychological effect known as "hindsight bias" might cause people to misinterpret the conclusions of the Columbia Accident Investigation Board (CAIB), according to an Ohio State researcher who helped the board during its probe.

The report makes important recommendations that could not only help NASA, but also other organizations, according to David Woods, professor in the Institute for Ergonomics and co-director of the Cognitive Systems Engineering Lab at Ohio State. Woods also is a professor in the Department of Industrial, Welding, and Systems Engineering.

David Woods   By Jo McCulty

Woods provided technical input on decision-making, organizational factors and hindsight bias to the CAIB during its investigation. His research on the factors that contribute to human error is referenced in chapter 7 of the report.

Woods gave an example of the dangers of hindsight bias, citing some text from the CAIB report. "Often the first question people ask about the decision-making leading up to the Columbia accident is, 'Why did NASA continue flying the shuttle with a known problem?'" he said.

The "known problem" refers to the dangers of debris damaging the shuttle wing during takeoff, which the board has identified as the physical cause of the accident.

But as soon as the question is posed in this way, readers risk oversimplifying the situation and the uncertainties people faced before the outcome was known, Woods said.

"Because it is difficult for readers to disregard what is commonly called '20/20 hindsight,' they can misinterpret the report and label NASA as a bad organization. As a result, the same difficulties that led to the Columbia accident could go unrecognized in other organizations, too," he added.

Just as the CAIB worked hard to overcome hindsight bias and find the organizational factors that led to the accident, Woods feels that readers of the report also will need to overcome their own hindsight.

The accident's lessons apply to all organizations that have to balance safety risks with pressure for efficiency. The key difficulty, according to Woods, is this: the most critical time for organizations to uncover safety risks is the one time when they can least afford diverting resources to do so -- when they are under heavy production pressures.

In the case of NASA, the organization is pressured to fly the shuttle on a certain schedule.

Woods noted that helping organizations maintain high safety despite production pressure is the topic of a newly emerging area of research known as resilience engineering.

"We can't change the past, despite the tragedy. But the future is open to us. Will the next accident report again describe how safety defenses eroded over time in the face of production pressure? If we recognize that the CAIB's analysis applies to all organizations, not just NASA, we can learn how to balance acute pressures for efficiency with a chronic need for high safety so that this pattern doesn't recur," he said.

With nearly 25 years of experience diagnosing the factors behind human error, Woods has conducted extensive research on how people interact with computers to make decisions in high-risk environments. His work has won awards for improving the safety of automated cockpits. In addition, Woods is a member of the National Research Council committee that is helping NASA and the Federal Aviation Administration plan the country's next-generation air transportation systems.

Study reveals why silicon crystals lose their "edge"

Physicists have discovered a mechanism that forces sharp edges on the surface of a silicon crystal to become rounded, and have described this rounding in detail for the first time. The new finding holds implications for the shape of other crystals used in the semiconductor industry, and might one day lead to templates for manufacturing tiny electronic parts, said William Saam, professor and chair of physics.

For instance, scientists could use this information to make patterns for wires that measure only a few nanometers (billionths of a meter) across, or even smaller semiconductors called quantum dots. Saam and a colleague derived equations that revealed a previously unknown series of phase transitions -- lines and points along the crystal surface that signal how atoms were forced to rearrange themselves to maintain stability. The kind of stability in question is called thermal equilibrium, and most solid objects can only reach complete equilibrium after they've been held at a fixed temperature for a very long time.

Saam said that he was surprised by the findings. "Our results clearly illustrate that you cannot have sharp edges in any crystals that are at thermal equilibrium," he said. "The edges have to be round, and round in very special ways."

www.osu.edu/researchnews/archive/siedge.htm