Category Archives: safety

Usability and Signing up for Campus Safety Alerts

With recent tragic events in the United States, there has been pressure for many University campuses to install emergency alert systems. These systems notify students, faculty, and employees of emergency events via email or mobile text messages.

A few months ago, I signed up to the one offered at my University. Today, I received the following note:

You recently signed up to receive Safe alerts on your cell phone. There is some confusion about the sign-up process and you are among a group of users who did not complete the steps that will enable you to receive emergency messages on your phone. [emphasis added]

Your safety is our paramount concern, so please go to [website] to see instructions to complete the process. You will need to find the checkbox labeled “text message” to receive the CU safe alerts on your phone.

We apologize for this confusion and hope to make the sign-up process simpler in the future.

I thought this was unusual because when I initially signed up, the process did not seem overly complicated. To be sure, it was not intuitive, but not complex either. I was certain that I configured the system to send email and text alerts. I guess I was wrong (along with a few other people).

One thing that makes the system seem so apparently complex is that the system is meant to be a general purpose notification system–not just emergencies. When I log in, I see all of the classes I’ve taught, research groups I belong to, etc. organized into “Channels.” Why can’t the system be just for emergency alerts? Then the sign up process would simply involve entering my email and mobile phone number and opting-in. Instead, it looks like this:

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I suppose it has to do with some kind of cost-benefit analysis. Why pay for a system that only handles emergencies when we can extend it to general purpose messaging?

For a future post, I should talk about our new warning sirens (which I cannot hear from my office, unfortunately).

Death from Branding

If you’re Apple, you want people to see the similarities between their iPod and their iPhone. However, if you are a drug manufacturer, you do not want similarities between adult and pediatric medicine.

Above are bottles of Heparin, manufactured by Baxter Healthcare. Both blood thinners, one of these vials is 1,000 times more concentrated than the other. Confusion between these two bottles killed infants at an Indiana hospital back in 2002. This article provides a good overview of past cases.

I actually remember reading about this back then, and thought “Wow, there’s a good human factors lesson. How awful that children had to die to bring it into the spotlight.”

Unfortunately, this lesson stayed unlearned, as two more children were administered the adult drug this week. Because these were the newborn twins of Dennis and Kimberly Quaid, who have already spoken out on 60 Minutes about medication mistakes, we may see the problem addressed more thoroughly in the drug industry.

On a final note, these cases touch on the human desire to blame other humans rather than the systems they interact with. In the Indiana case, a mother who lost her child was quoted as saying:

… who blames the nurses, not drug labeling, for her daughter’s death. “I don’t think it was from the label,” she said. “They are both blue, but one is lighter than the other. How could they mistake those?”

Change blindness, automaticity, expectation, fatigue, and time pressure are but a few of the factors that might have caused the error. Sometimes, it isn’t a case of someone not just “being careful.” This is actually a good thing: we can understand and solve human factors problems. We can’t make someone care.

Welcoming the Fireproof Elevator

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NPR ran a story earlier this week on an intriguing new human factors problem: fire-safe elevators.

The fall of the World Trade Center made it painfully obvious that stairs in skyscrapers do not function adequately in emergencies. We’ve always been warned away from elevators in case of fire, and I would go so far as to say it part of our collective knowledge from a young age. With the advent of elevators you should use in a fire comes a host of difficulties.

1. Training the zeitgeist: Not all elevators will be replaced, though new tall buildings will all have fireproof elevators. There may be new rules requiring older buildings over a certain size retrofit at least one elevator as fire safe.

  • This still makes fireproof elevators the exception instead of the rule. A great research question would be how to train people for a small-percentage case? You want the public, of all ages and experience levels, to know “In case of fire, use stairs, unless there is a fireproof elevator around, which you may or may not have noticed while you were in the building.”

2. Warnings and Information: The symbol in this post is probably familiar to all of you. I’ve occasionally seen it in Spanish, but not often. How will we indicate the difference between fire-safe elevators and other elevators?

  • Decals, signs and other indicators will not only have to indicate which elevators are safe and their purpose, but whether other elevators in the building are safe or unsafe. My building is square, with elevators on mirrored sides. If one were safe and the other not, I am sure I could remember which was safe, especially under the cognitive demands of an emergency.

3. Wayfinding and luck: Use of the elevator may depend on the location of the fire.

  • One of the original problems was that elevators opened onto smoke-filled or fire-filled floors. The story did not specify how the new elevators would avoid this. If there is a sensor that prevents them from opening onto such a floor, what if there are people desperately waiting for the elevator on that floor (as they have been re-trained to do)?
  • Should the system be even more complex, with people gathering on certain floors to await the elevator rescue? And then, if those floors are on fire..

In short, researchers start your engines! We have some training, warning, design, and way-finding work to do.

‘Mind-reading’ car keeps drivers focused

A “smart” dashboard that reduces the amount of information displayed to drivers during stressful periods on the road could be available in just five years, say German engineers.

A team from the Technical University of Berlin found they could improve reaction times in real driving conditions by monitoring drivers’ brains and reducing distractions during periods of high brain activity.

They were able to speed up driver’s reactions by as much as 100 milliseconds. It might not sound much, but this is enough to reduce breaking distance by nearly 3 metres when travelling at 100 kilometres per hour, says team leader Klaus-Robert Müller.

[NewScientist]

NPR covers a good bit of the HF field in one conversation with two doctors

All Things Considered interviewed Dr. Peter Pronovost this weekend about the checklist he developed for doctors and nurses in busy hospitals. On a topical level, this illuminated the working memory demands of hospital work and statistics on how easy it is to err.

As an example, a task analysis revealed almost two hundred steps medical professionals do per day to keep the typical patient alive and well. On average, there was a 1% error rate, which equates to about two errors per day, per patient.

Pronovost introduced checklists for each type of interaction, which resulted in Michigan hospitals going from 30% chance of infection (typical across the US) to almost 0% for a particular procedure.

Could something as simple as a checklist be the answer? No, because this intervention wasn’t “just” a checklist.

Whether trained in these areas or not, the doctors interviewed had to understand:

Team training: Nurses are trained not to question doctors, even if they are making a mistake. Solution: Pronovost brought both groups together and told them to expect the nurses to correct the doctors. (Author note: I’d be interested to see how long that works.)

Social interaction: In an ambigous situation, people are less likely to interfere (e.g., the doctor didn’t wash his or her hands, but the nurse saw them washed for the previous patient and thinks “It’s probably still ok.” Checklist solution: eliminate ambiguity through the list.

Effects of expertise: As people become familiar with a task, they may skip steps, especially steps that haven’t shown their usefulness. (e.g., if skipping a certain step never seems to have resulted in an infection, it seems harmless to skip it). Checklist solution: enforce steps for all levels of experience.

Decision making: People tend to use heuristics when in a time-sensitive or fatigued state. Checklist solution: remove the “cookbook” memory demands of medicine, leaving resources free for the creative and important decisions.

Design out, Guard, then Warn

Check out this fascinating solution to protecting users from the blade of a table saw.

The way it works is that the saw blade registers electrical contact with human skin and immediately stops. I can’t imagine not having this safety system in place, now that it is available. However, I still have some questions that commenters might want to weigh in on:

1. Unless the system is more redundant than an airplane, it must be able to fail. How do you keep users to remain vigilant when 99.999% of the time there is no penalty for carelessness?

2. To answer my own question, is the fear of a spinning blade strong enough to do that on its own? I know I’m not going to intentionally test the SawStop.

3. Can we use natural fears such as this in other areas of automation?

4. For great insight into human decision making, read this thread on a woodworking site. What would it take to change the mind of this first post-er?

When do we as adult woodworkers take responsibility and understand the dangers of woodworking. Most accidents happen due to not paying attention to what we’re doing. If we stay focused while we’re using power tools, or even hand tools, we eliminate accidents.”

Intuition vs Experience with Roundabouts

Some people might say a traffic circle is obvious. There is only one way to go.. who yields might be more difficult, but at least we are all driving in the same direction.

Not so.

The following two articles come down on the side of experience for the usability of roundabouts.

New Traffic Circle Causes Confusion

Death-crash car launches off the road and into a first floor flat

I am sure the designers believed that if millions of people in London and hundreds of thousands in New Orleans can handle a roundabout, these citizens of a town so small they don’t even bother to mention where it is would do fine.

Why Human Factors is more than providing safety equipment

The new math and physics building is going up outside my window at North Carolina State. I see the workers out there each day, and as the building gets higher they are obviously required to don different safety gear.

The fuzzy picture below shows two workers on the top level (7th floor) and the green highlight is my outline of the full body harness and safety cord the man is wearing. Indeed, it seemed necessary as whatever tool he is using seems to push him off balance with every use (some sort of nail gun?)

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However. Unlike the man behind him, this worker has not attached his safety cord to anything. It merely drags along behind him as he walks around the platform and crawls in and out of the scaffold. In fact, it seems to get in his way when the clasp on the cord catches on the corrugated surface of the platform.

Legal Interpretations can be the Bane of Good Human Factors

Verizon wireless interpreted an accessibility requirement to require they trigger a notification when the user dials 911. Verizon chose to do this audibly… exactly what you DON’T want when you’re calling the police during an emergency!

“The tone our customer experienced is our interpretation of Section 255 of the Telecommunications Act calling for a provider of telecommunications service to offer service that is accessible and usable by individuals with disabilities. The tone, indicating that 911 has been dialed, is one of several features designed to make wireless service is accessible and easy to use, especially for those with disabilities. Other features include a voice command key where customers can use their voice to dial by name or number; a voice echo feature so that a person who can’t see can hear the number or letter if sending a text; read back text messages and speech output of signal strength, battery strength, missed calls, voicemail, roaming, time and date.”

Read the full news article here.

Perhaps there was no time for use cases or personas. “Debbie sees 4 masked men breaking into her home. Trapped, she hides in the closet and dials…. oh. Wait, guys. I think we have a problem.”

“Set Phasers on Stun” still relevant in healthcare industry

Center Treats Wrong Side Of Patient’s Brain

DETROIT — A patient undergoing treatment at the Karmanos Cancer Institute in Detroit received a dose of radiation on the wrong side of the brain, according to a report filed with the United States Nuclear Regulatory Commission.

According to the report, a crucial piece of information was misread prior to treatment with a gamma knife, which delivers a targeted form of radiation therapy that zeros in on specific locations in the brain.

The patient went through a routine MRI (magnetic resonance imaging) scan of the brain just before the procedure, but went into the scanner “feet first,” rather than the standard practice of head first, the document said.

“The gamma knife-authorized medical physicist failed to recognize the scanning error when importing the MRI images into the Gamma Knife treatment planning computer, and subsequently registered them as head first,” the report said. “This resulted in the wrong side of the patient being targeted and treated.”

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What went wrong? Deviation from standards (if there are standards)? Too-busy doctors? I’ll be interested to see who gets the blame.