Category Archives: errors

Institutional Memory, Culture, & Disaster

I admit a fascination for reading about disasters. I suppose I’m hoping for the antidote. The little detail that will somehow protect me next time I get into a plane, train, or automobile. A gris-gris for the next time I tie into a climbing rope. Treating my bike helmet as a talisman for my commute. So far, so good.

As human factors psychologists and engineers, we often analyze large scale accidents and look for the reasons (pun intended) that run deeper than a single operator’s error. You can see some of my previous posts on Wiener’s Laws, Ground Proximity Warnings, and the Deep Water Horizon oil spill.

So, I invite you to read this wonderfully detailed blog post by Ron Rapp about how safety culture can slowly derail, “normalizing deviance.”

Bedford and the Normalization of Deviance

He tells the story of a chartered plane crash in Bedford, Massachusetts in 2014, a take-off with so many skipped safety steps and errors that it seemed destined for a crash. There was plenty of time for the pilot stop before the crash, leading Rapp to say “It’s the most inexplicable thing I’ve yet seen a professional pilot do, and I’ve seen a lot of crazy things. If locked flight controls don’t prompt a takeoff abort, nothing will.” He sums up the reasons for these pilot’s “deviant” performance via Diane Vaughn’s factors of normalization (some interpretation on my part, here):

  • If rules and checklists and regulations are difficult, tedious, unusable, or interfere with the goal of the job at hand, they will be misused or ignored.
  • We can’t treat top-down training or continuing education as the only source of information. People pass on shortcuts, tricks, and attitudes to each other.
  • Reward the behaviors you want. But we tend to punish safety behaviors when they delay secondary (but important) goals, such as keeping passengers happy.
  • We can’t ignore the social world of the pilots and crew. Speaking out against “probably” unsafe behaviors is at least as hard as calling out a boss or coworker who makes “probably” racist or sexist comments. The higher the ambiguity, the less likely people take action (“I’m sure he didn’t mean it that way.” or “Well, we skipped that list, but it’s been fine the ten times so far.”)
  • The cure? An interdisciplinary solution coming from human factors psychologists, designers, engineers, and policy makers. That last group might be the most important, in that they recognize a focus on safety is not necessarily more rules and harsher punishments. It’s checking that each piece of the system is efficient, valued, and usable and that those systems work together in an integrated way.

    Thanks to Travis Bowles for the heads-up on this article.
    Feature photo from the NTSB report, photo credit to the Massachusetts Police.

    Helmet Design and Environment Interaction

    I wanted a new helmet that offered some side-impact protection to replace my trusty Petzl Ecrin Roc, especially after a helmet-less Slovenian climber mocked me in Italy for wearing “such a heavy helmet” at a sport climbing crag.

    I now own the Petzl Meteor, but after one trip discovered a strange design flaw.

    Most helmets clip together the way carseats or backpack buckles clip together:
    clip

    The Petzl Meteor helmet has a similar clip, but also contains magnets that draw the buckle together. Here is how it should work:

    I was climbing at Lover’s Leap in California, a granite cliff. Those of you who know your geology might guess what happens when you combine magnets and iron-rich granite. I put the helmet on the ground while sorting gear, put it back on and heard the buckle snap together. A few minutes later, I looked down (which put some strain on the helmet strap), the buckle popped open, and the helmet fell off my head.

    When I examined the buckle, there was grit stuck to the magnet.

    Iron grit on magnet
    Iron grit on magnet

    Wiping it off seemed to work, except that it moved some of it to the sides rather than just the top. My fingers weren’t small enough to wipe it from the sides. So, the next time I snapped it shut and checked to make sure it was locked, I couldn’t get it off. The grit on the side prevented the buckle from pinching enough to release. I was finally able to get it off the sides by using part of a strap to get into the crevices.

    Iron grit on sides

    I made some videos of the phenomenon. It was pretty easy to do, I just had to put my helmet on the ground for a moment and pick it up again. Attached grit was guaranteed – these are strong magnets!

    I am not the only person to notice this:

    In one review of another helmet with a similar closure:

    The only issue I had with the buckle came after wearing the Sirocco while bolting and cleaning a granite sport route. Some of the swirling granite dust adhered to the magnets, obstructing the clips. It was easy enough to fix: I just wiped the magnets clean, and it has worked perfectly since.

    and:

    Helmet review from Outdoor Gear Lab

    What we found in our tests of both the Meteor and the Sirocco was that the magnet did not always have enough oomph to click both small arms of the buckle completely closed. About one in four times, only one of the plastic arms would fasten and the buckle would need an extra squeeze to click the other arm in. Another thing our testers noticed was that the magnet would pick up tiny pebbles which would prevent the buckle from fully closing. The pebbles can be easily cleaned by brushing off the exposed part of the magnet, but it adds an extra step to applying the helmet. The bottom line is, we prefer the simplicity of the old plastic buckle. We think that the magnet is a gimmick which potentially makes a less safe helmet.

    Safety gear shouldn’t add steps to be remembered, such as making sure the buckle is locked, even after getting auditory and tactile feedback when one connected it. Some people may never climb in an area with iron in the ground, but the use-case for a granite environment should have been considered. You know, for little climbing areas such as the granite cliffs of Yosemite.

    Rock Climbing Human Factors – Harness attachment points

    A friend of mine was recently rappelling from a climb, meaning that she had the rope through a device that was connected to her belay loop on her harness. As she rappelled, she yelled that her harness broke, and the waistband of the harness slid nearly to her armpits. Fortunately, she remained calm and collected, and was still able to rappell safely, if awkwardly, to the ground. On the ground, her partner saw that her waistband with belay loop had become disconnected from her leg loops. The leg loops were intact, though a keeper-strap that helps the leg loops stay centered was no longer connected.

    So, what happened?

    First, for the non-climbers, a primer. A climbing harness is composed of three major parts, attached to each other in various ways depending on the manufacturer. The first part is the waistband, which is load-bearing, meaning that it is meant to take the weight of a climber.

    The second part of the harness is the belay loop, a load-bearing stitched circle that connects the waistband and leg loops and is also used to hold a belay device, to hold the climber’s weight when rappelling, and for anchoring to the ground or a wall when needed.

    The last part of the harness is the leg loops, which are also load-bearing in the parts that connect to the belay loop and around the legs themselves.

    Figure 1 shows the general composition of climbing harnesses, with these three parts diagrammed in the Base Concept.

    harness_leg_loop_error
    Figure 1. Simplified diagrams of climbing harnesses.

    On most harnesses, the leg loops are kept connected to the belay loop by a “keeper strap.” This is usually a weak connection not meant to bear weight, but only to keep the leg loops centered on the harness (shown in blue in figure 1). In the case study that prompted this blog post, the keeper strap was connected through the belay loop, rather than the full-strength leg loops (figure 2.) When loaded, it came apart, separating the leg loops from the waistbelt. My own tests found that the keeper strap can be very strong, when it is loaded on the strap itself. But if the leg loops move so that the keeper buckle is loaded by the belay loop, it comes apart easily.

    errorharness
    Figure 2. Harness assembled with keeper strap bearing weight via the belay loop.

    There are two ways to mis-attach leg loops to the belay loop of a harness. The first way is by connecting the leg loops back to the harness, after they were removed, using the keeper strap. The video below demonstrates this possibility. Once connected, the harness fits well and gives little indication the leg loops are not actually connected to bear weight.

    The second (and I think more likely) way is by having the leg loops disconnected from the back of the harness, usually for a bathroom break or to get in and out of the harness. The leg loops are still connected in the front of the harness, but if a leg loop passes through the belay loop, suddenly the keeper strap is load bearing when the leg loops flip around. However, the harness does not fit differently nor does it look particularly different unless carefully inspected. Video below.

    The non-load bearing parts of the harness are what determine the possibility for this error. In figure 1, some harnesses either do not allow disconnection of the leg loops in back or only allow their disconnection in tandem. When the leg loops are connected in this way, the front of the leg loops cannot be passed through the belay loop. Video demonstration below.

    Back to figure 1, some harnesses allow the disconnection of leg loops for each leg. If these are disconnected, a loop may be passed through the front belay loop, resulting in the error in figure 2.

    In sum, this error can be examined for likelihood and severity. It is not likely that the error occurs, however if it does occur it is likely it will go undiscovered until the keeper strap comes apart. For severity, the error could be lethal, although that is not likely. The waistbelt will hold the climber’s weight and having leg loops and a waistbelt is a (comfortable) redundancy. However, the sudden shock of suddenly losing support from the leg loops could cause loss of control, either for an un-backed-up rappell or while belaying another climber.

    What are the alternatives?

  • Climbing is exploding, particularly climbing in gyms. The “gym” harnesses, with fewer components and gear loops (Figure 1), are a good option for most climbers now. However, there is little guidance about what harness one should buy for the gym vs. outdoor versatility so few probably know this harness is a good option.
  • Some harnesses are designed to be load-bearing at all points (i.e., “SafeTech” below). It is impossible to make an error in leg loop attachment.
  • safetech

  • Harnesses with permanently attached leg loops or loops that attach in the back with a single point are unlikely to result in the error.
  • Many climbers reading this are thinking “This would never happen to me” or “You’d have to be an idiot to put your harness together like that” or my usual favorite “If you wanted climbing to be perfectly safe, you shouldn’t even go.” Blaming the victim gives us a feeling of control over our own safety. However, there are other instances where gear was assembled or re-assembled incorrectly with tragic consequences. No one (or their child) deserves to pay with their life for a simple mistake that can be prevented through good design.

    Parking sign re-design

    I’ll be the first to admit that I experience cognitive overload while trying to park. When there are three signs and the information needs to be combined across them, or at least each one needs to be searched, considered, and eliminated, I spend a lot of time blocking the street trying to decide if I can park.

    For example, there might be a sign that says “No parking school zone 7-9am and 2-4pm” combined with a “2 hour parking only without residential permit 7am-5pm” and “< —-Parking” to indicate the side of the sign that’s open. It’s a challenge to figure out where and how long I can park at 1pm or what happens at 7pm.

    Designer Nikki Sylianteng created new signs for parking in Los Angeles that incorporated all information into a single graphic.

    http://nikkisylianteng.com/project/parking-sign-redesign/
    http://nikkisylianteng.com/project/parking-sign-redesign/

    I still have some difficulty in going back and forth to the legend at the bottom, but probably just because I’ve never seen the signs before. Otherwise, one just needs to know the time and day of the week.

    An interview with her can be found in the LA Weekly where she describes mocking up a laminated example in NY and asking people for feedback on the street via sharpies. (Yay for paper prototypes!) An NPR story focused on the negative reactions of a few harried LA denizens, who predictably said “I like how it was,” but I’d like to see some timed tests of interpreting if it’s ok to park. I’d also like to suggest using a dual-task paradigm to put parkers under the same cognitive load in the lab as they might experience on the street.

    As for NY parking signs – I still can’t parse them.

    The Square Cash Disappearing Act

    Square Cash is a great service – it allows you to send money via an email with no service charge if you’re using your debit card. You can receive money without entering a PIN. I use it all the time to divide up restaurant bills among my friends. That said, I found a usability issue yesterday that I wanted to share.

    I needed to link my debit card to the app, so I followed their very simple instructions for entry. 

    The first screen asks for the card number. The number pad is telephone-order rather than number pad-order. This is on a phone, so that makes sense even if I’m much more used to entering these numbers using a keyboard.

    IMG_4841

    Next, the expiration date. On my card, the expiration date is 09/16/2016*, so I start to enter it.

    IMG_4842

    Here is the screen as you start to enter the date:
    IMG_4843

    I then proceeded to enter 09/16 as I looked at my card, then the CCV, and got an error message about an incorrect card number. Tried again. Same. Did this four times before I realized that the expiration date was month/year. It isn’t as though I’d never seen this, or been asked to enter just the month and year from a card, so I thought hard about what tricked me.

    I concluded it was the difference between the second and third screens – the guidance is there before you start typing, but as soon as you put in any number for the date, the guidance disappears. Since I was looking down at my card, I just entered what I saw and didn’t think enough to check – especially since it called for ##/##, which matched the month and day on my card, not ##/####, which could only be a month and year.

    You are welcome to blame the user for this one, but it would be a small fix to keep the background guide visible during entry.

    *No, I’m not dumb enough to put my real card number or expiration date in the pictures for this post. 🙂

    Haikuman Factors

    Sometimes it’s good to take a step back from the seriousness of our work and find new focus. H(aiku)man factors is the brainchild of my colleague Douglas Gillan. Each summarizes a concept in the field while following the haiku form of 5-7-5 and an emphasis on juxtoposition and inclusion of nature. Enjoy and contribute your own in the comments!

    H(aik)uman Factors3

    H(aik)uman Factors2

    H(aik)uman Factors

    H(aik)uman Factors6

    H(aik)uman Factors5

    H(aik)uman Factors4

    All of the above are by Doug Gillan.

    Other contributions:

    Inattentional blindness by Allaire Welk
    Unicycling clown
    Challenging primary task
    Did you notice it?

    Affordances by Lawton Pybus
    round, smooth ball is thrown
    rolls, stops at the flat, wing-back
    chair on which I sit

    Escalation by Olga Zielinska
    headache, blurred vision
    do not explore Web MD
    it’s not a tumor

    Automatic Processing by Anne McLaughlin
    end of the workday
    finally get to go home
    arugh, forgot groceries

    Automation by Richard Pak
    Siri, directions!
    No wait, I’ll get it myself
    Drat, I forgot how

    Prospective Memory by Natalee Baldwin
    I forgot the milk!
    Prospective memory failed
    Use a reminder

    Working Memory by Will Leidheiser
    copious knowledge.
    how much can I remember?
    many things at once.

    Radio interview with Rich

    Our own Rich Pak was interviewed by the Clemson radio show “Your Day.”

    Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

    They cover everything from the birth of human factors psychology to the design of prospective memory aids for older adults. Enjoy!

    Worst Mobile Interface Ever

    I was reading articles the other day and came across a site that, as many do, reformatted for my phone. Almost all reformatted-for-mobile sites are terrible, but this one is my favorite.
    photo
    You cannot scroll through the 21 page article by moving your finger up and down, as would happen on a website. The only way to change pages is via the horizontal slider at the bottom. Good luck trying to move it so slightly it only goes forward one page! And yes, moving the slider left and right does move the page up and down.

    Brilliant guard against accidents in indoor rock climbing

    For those who don’t follow news of climbing accidents as closely as I do, there has been a spate of accidents associated with the automatic belay devices (autobelays) installed at climbing gyms.

    These devices are handy to have around as they negate the need for a climbing partner, allowing one to exercise and train alone. The climber clips his or her harness into the device at the bottom of the wall, and it automatically retracts (like a seat belt) when you climb upward. At the top, you let go of the wall and the device lowers you slowly back to the ground. You are probably imagining that the accidents had to do with failures of the equipment – while that is not unheard of, the most recent issues have all been with climbers forgetting to clip into the system at all.

    The most recent tragedy occurred this past September, where an experienced climber died after a fall in a Texas gym, and it’s been listed as so common it happens at “every gym,” though not always resulting in a fall. Here is the facebook page with members of another gym discussing a similar accident.

    fb

    If you talk with climbers or read accident forums you will invariably be faced with a large contingent bent on blaming the victim. I’ll grant that it is hard to imagine forgetting to clip into a safety device and climb 30 feet up a wall, but that’s because I hardly ever do it. One characteristics these accidents share is that the victims were experienced and used the auto-belays frequently.

    When a procedure becomes automatic, it becomes more accurate and less effortful, but it also becomes less accessible to the conscious mind. When a step is skipped, but all other steps are unaffected, it’s especially hard to notice the skipped step in an automatic process. If caring more or working harder or “being more careful” could actually prevent this type of problem, we wouldn’t have any toddlers left in hot cars, perfectly good airplanes flown into the ground, or climbers falling because they didn’t clip into the autobelay.

    That brings me to the device I saw installed at a climbing gym last night.

    guardAbove: The guard in place, clipped to the wall and ready to go. Notice how it blocks the footholds of the climbs.

    photo 2Above: Nikki shows how to unclip the guard before attaching to her harness.

     

    photo 4Above: Clipped in and safely ready to go. Guard is on the ground and out of the way (it is ok to step on it!)

    Let me tell you why I think this is brilliant.

    • It’s highly visible.
    • It functions as a guard. This adheres to the hierarchy of safety: First, try to design out the hazard. Second, guard against the hazard. Last, warn. These are in order of effectiveness. Prior to this device, I had only seen signs on the wall saying “Clip in!” (And a year ago, even those didn’t exist.) This device physically blocks the start of the climbing routes, demanding interaction before one starts climbing.
    • Using it properly does not add any additional time or mess to climbing a route. If it weren’t there, the climber would still have to unclip the autobelay from an anchor close to the ground, etc. With it there, the climber does the same thing and once done, the guard becomes a flat mat that doesn’t get in anyone’s way.

    Is it perfect? No. You can also climb with a belayer on the same or nearby routes, and then it’s also blocking your way at the start of the climb. Some adaptation should be made by the route-setters at the gyms to minimize this. But overall, what a great and simple solution.

     

    The Future Newsroom (bad touchscreen lag)

    fox

    This clip of Fox News’ new studio has been tearing up the internet. But what caught my eye was the touchscreen lag and general unresponsiveness/accidental touches of the users in the background (see image at top; video here). Starting at the 10 second mark, note the user on the right.