Tag Archives: safety

This Human Factors Problem Should Be History By Now

An old problem has hit the news again: chemicals that look too much like drinks. This story just came out in New Jersey, where six people drank tiki-torch fuel the color of apple juice.

It is an interesting problem… what SHOULD you make fuel look like? The tiki-torch fuel bottle did not fall into the Fabuloso problem of looking like a sports drink bottle*. It wasn’t being kept under the bar, like the caustic dish liquid that scarred a father and daughter in “Set Phasers on Stun.” It doesn’t taste sweet like anti-freeze.

Yet when six people all make the same mistake, in a short time span, in a wide geographic spread, are of different ages, etc., it’s safe to assume something triggered them to think it was drinkable. As the executive director of the New Jersey Poison Information and Education System said in the article from the Star-Ledger:

“During my 40 years in medicine, you get an occasional kid who ingests kerosene, but I have never seen this kind of cluster,” he said.”

But what was it? From looking at the bottle, I don’t have a good answer.

*Fabuloso refused to change their bottle shape but made the concession of adding a child-proof cap. As the other stories show, it’s not just kids making these errors, but the cap should at least make the user think as they try to open the “sports drink.”**

**Of course that reminds me of the time I bought a new contact lens solution and opened it to see a bright red bottle tip. “What a neat retro-looking design,” I thought before filling the contact and putting it in my eye. An hour of rinsing later, I still thought maybe I’d blinded myself.

Primary Sources for Safety

Freakanomics posted an interesting discussion with several construction workers, asking them what they thought the biggest safety concerns were in their area.

The plural of anecdote may not be data, but this is a good start if anyone wants to look at whether regulation (via unions) contributes to safety, what safety rules are ‘annoying’, and construction worker locus of control.

“What’s one safety rule you would initiate at your workplace? What rules are unnecessary?

On union jobs the safety rules tend to be comprehensive, and effectively enforced. On non-union jobs — haha.

Many non union jobs are criminally negligent about safety. And after years of Republican rule of federal government there is little realistic enforcement. In other countries when workers are killed in, say, a building collapse, somebody goes to prison when negligence is proven. Here they might be fined a paltry sum.

I have yet to encounter a safety rule that was unnecessary. Although some are annoying — like wearing masks.”

“What’s one safety rule you would initiate at your workplace? What rules are unnecessary?

I can’t think of any specific “rule” I would initiate … 98 percent of safety is just paying attention to what you are doing and to your surroundings.

You can’t mandate good judgment. Although many of the rules are good and grounded in common sense (they do create a general “culture” of safety), sometimes the letter of the law, so to speak, is enforced too much.

Many times you stand there and say, “I understand why this rule exists, but when applied blindly in this situation, it just doesn’t make sense.”

John Wayne, United Airways, and Human Factors

Most everyone probably heard about the gun accidentally fired in the passenger plan cockpit last week.

But did you hear about the designs that lead to this human error?

I had to do some detective work (and quizzing gun owners) to find the following pictures:

Here is the gun in question (or similar enough) showing the safety and the spaces in front of and behind the trigger.

pilotgun.jpg

Pilots keep the gun in a hoster (see below).

Users report some difficulty ascertaining whether the gun is “locked” into the holster. If it is not, then the trigger can be in an unexpected place (namely, higher in the holster than the shaped holster seems to indicate.)

The TSA requires pilots who have been issued these guns to padlock the trigger for every takeoff and landing. Reports are that pilots do this about 10 times for a shift. Therefore, let’s assume we have 10 chances for error in using the holster and in using the padlock.

tsaholster.jpg

The padlock goes through the trigger. It should go behind, to keep anyone from pulling the trigger. If the gun is 100% in the holster, this is the case. If it is not… then the padlock can end up in FRONT of the trigger. The opaque holster prevents a visual check of the trigger.

The holster also prevents a visual check of the safety.

All of this might be forgiven, or addressed with training, if it weren’t for the fact that there are numerous other ways to prevent a gun from firing rather than locking something through the trigger. Remember, we should be on the “Guard” step of “Design out, Guard, then Train.”

I’m not even going to discuss whether pilots should have guns.

“Boyd said he supports the program to arm pilots, saying, “if somebody who has the ability to fly a 747 across the Pacific wants a gun, you give it to them.”

For an amusing take, see “Trust is not Transitive.”

Educational (low-priced) laptops and cross-cultural Human Factors

In the past year, there has been an explosion of interest in the very low end of portable computing. This started with the introduction of the One Laptop Per Child project (OLPC). Quickly followed by the Asus EEE pc, Intel Classmate PC, and Everex Cloudbook. These bare bones and ultra portable laptop computers are ostensibly targeting users who would like a computer but can’t afford one. But one topic I have yet to hear about is an analysis of the usability or human factors aspects of these machines.Only the education-focused OLPC (and maybe the Classmate PC) is explicitly targeting an international, student-aged audience. Incidentally, only the OLPC has a somewhat novel interface (dubbed Sugar). The interface is dominated by pictographs with little use of text:

olpc2.jpg
OLPC screen shot

Given the extremely wide audience for these types of computers, I wonder how much work has gone into testing the usability of Sugar, or the other operating systems in these machines. In addition, given the extremely varied audience (in age, educational level, technological skill level, socio-economic status, just to name a few), does this one-size-fits-all strategy work? There has been research illustrating that even within a culture, pictograms are not universally understood.

My experience with open-source software (which all of these machines can run) has been that ease of use has never been a priority. Here is a quick visual comparison of the current machines.

Continue reading Educational (low-priced) laptops and cross-cultural Human Factors

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).

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.”

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?)

workers.jpg

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.

“From the Doctor’s Brain to the Patient’s Vein”

It appears that HFB needs an entire section devoted to medical error. This is not surprising in light of the thousands of Americans who die from preventable errors each year.

The latest comes from Tanzenia where confusion about patient names earned brain surgery for a twisted knee, and knee surgery for a migraine sufferer.

Mr Didas who had been admitted for a knee operation after a motorbike accident is still recovering from the ordeal – he ended up unconscious in intensive care after his head was wrongly operated on. And chronic migraine sufferer Emmanuel Mgaya is likewise, still recovering from his unplanned knee surgery. The blunder was blamed on both patients having the same first name.
But a hospital official, Juma Mkwawa said it was the worst scandal that had happened at Muhimbili hospital and that, “sharing a first name cannot be an excuse”. The two surgeons responsible have been suspended. (BBC)

Before anyone retreats into the comfort of “that wouldn’t happen here,” I suggest a look at the growing literature on similar medication names and their consequences.

It is easy to be the bearer of sad stories and ill tidings. I would rather on a note for a hopeful future. Below are researchers and companies dedicated to identifying and eliminating causes of medical error.

Please add more in the comments section if you know someone working in this important context.

The New Field of Unmanned Aircraft

Though for some, turning war into a video game might remind them of 1984, unmanned aircraft offer unparalleled safety to the pilot.

NPR recently covered the technological and social changes that come with unmanned aircraft, but the human factors of tracking, flying, and manipulating the Predator was not mentioned.

Obvious issues include:

  • Lag time from the camera halfway around the world
  • Limited acuity and field of view
  • Decision-making (e.g., bombing a target on a screen vs. dropping a bomb on people)
  • High loss of equipment (if not pilot life)

In short, I worry that the news presented to the public paints a too-rosy picture of these aircraft, implying that we will eventually have robots fighting robots from the comfort of our own homes.

I’d like to hear from people what they consider to be the most interesting human factors challenge of unmanned vehicles. I don’t know much about the design of their interfaces and whether they are more similar to a cockpit or a game console, but I’m interested to learn. Feel free to comment!

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cockpit