Category Archives: automation

Mining Tragedy Update

There is new information on the West Virginia coal mine tragedy where the methane detectors were disabled to prevent automatic shut down of the machinery. This comes from NPR:

Methane monitors are mounted on the massive, 30-foot-long continuous miners because explosive gas can collect in pockets near the roofs of mines. Methane can be released as the machine cuts into rock and coal. The spinning carbide teeth that do the cutting send sparks flying when they cut into rock. The sparks and the gas are an explosive mix, so the methane monitor is designed to signal a warning and automatically shut down the machine when gas approaches dangerous concentrations.

Because the monitor continually shut down the machine:

On Feb. 13, an electrician deliberately disabled a methane gas monitor on a continuous mining machine because the monitor repeatedly shut down the machine.

Three witnesses say the electrician was ordered by a mine supervisor to “bridge” the automatic shutoff mechanism in the monitor.

There is some discussion as to whether the monitor was malfunctioning and shutting the machine down when it should not have or whether it was shutting down due to actual methane in the air. People in many industries willfully disable aids meant to keep them safe and malfunction is only one of the variables that affects the behavior (granted, it’s likely a big one). Here is one example from agriculture, collected for NIOSH through the FACE database program*:

A 26-year-old Hispanic male knitting machine operator died when he was crushed by moving parts within the knitting machine as he tried to make an adjustment.  The victim opened a safety gate and jammed a needle in the “on” button that allowed the machine to operate with the safety gates open.

Last, in at least this one case the safety cut-off contributed to an accident.

On June 4, 2004, a 47-year-old co-owner of a recycling business was run over and killed by a Gradall telescopic boom lift (rough-terrain forklift) while he was working underneath it. He had been operating the Gradall, and had shut it down when he momentarily exited the vehicle. When he returned to the machine, he found it would not restart. The Gradall had a safety interlock that prevented starting from the ignition switch while in gear. The contractor was apparently unaware of this safety feature. He checked the batteries, and then crawled underneath the cab area and reached up into the engine compartment with a screwdriver. The screwdriver made contact between the two terminals on the starter, effectively jump-starting the engine and bypassing the safety mechanism that prevented ignition while in gear. The Gradall started and moved forward. The parking brake was not set. The back left tire rolled over the contractor.

In short, I admire but do not envy the designers who have to create these dangerous systems. Their users are inventive, under pressure, and different from each other in countless ways. Designing safety sounds easy (one can imagine  “just make it shut off when they aren’t using it,”) but the answers seem far from being so simple. Many of the examples I have seen from other industries show quick and easy ways to bypass a safety system.

  • Machinery automatically cuts off after 8 seconds when there is no weight in the driver’s seat. Worker keeps a heavy tool bag nearby to put on the seat when the worker wants to check on things outside the cab.
  • Same system as above – worker tries to jump out of cab and complete task in less than 8 seconds.
  • Worker cannot reach objective with lap safety bar in place, a bar that must be down for machinery to operate. Worker lifts bar then puts it back down across empty seat and reaches for objective with machinery running.

There does seem to be a difference in premeditation in the examples I’ve come across and the idea of hiring an electrician to specifically and more permanently remove a guard from a safety system.

*I have posted on the FACE program before. It is a valuable repository.

Photo Credit NIOSH on Flickr

Usability Potpourri

HF/Usability Potpourri returns with two recent items.

iPhone Reception Display

Reports from some sites suggest that at least some of the cellular reception issues of the new iPhone 4 are due to improper display of signal strength.  This is a neat HF issue because it involves user’s trust in automation (the display of reception bars is actually a computed value, not a raw meter of actual signal strength), the design of information displays, and properly informing the user so they can set expectations.  Apple is planning to tweak the way in which those bars get calculated (presumably to be less optimistic) to bring user expectations in-line with reality.

From an Apple press release:

Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong. Our formula, in many instances, mistakenly displays 2 more bars than it should for a given signal strength. For example, we sometimes display 4 bars when we should be displaying as few as 2 bars.

Mozilla Browser Visualization

Next, Mozilla, creators of Firefox, present some interesting visualizations of what users are clicking in Firefox.  As expected, the back button is one of the most frequently clicked items (93% of all users).

Interestingly, the RSS icon in the location bar (the orange square icon used to subscribe to blogs) showed some operating system differences.  Five percent of PC/Windows users clicked it, 11% of Mac users, and about 14% of Linux users.  Indicative of experiential differences?  PC users less aware of blogs/blog readers?

Our own analytics show that the vast majority of our readers visit from PC-based Firefox installations.  As a service to our readers, here is the subscribe link to our blog 🙂

Dangers of Automatic Windows

Recently I posted on some potential human factors problems caused by Toyota’s design of their floor mats. For this post, I would like to compliment Toyota on their automatic power windows. The windows can be lowered fully and automatically by one quick press on the button. However, to be raised, the lever on the button must be continuously raised until the window closes.

This is good for two reasons:

  • if it raised automatically, people and pets could be easily hurt by the closing window.
  • if the buttons were press-only (or a toggle), a knee, hand, paw, or other object can cause the window to close on something unintentionally.

I did not appreciate these functions until operating a Honda window recently that closed with one upward pull of the button, when I did not intend to close it.

Consumer Reports recently published an article on this design problem. There are many injuries each year from automatically closing windows and some deaths, usually children. There is new legislation to require that windows auto-reverse when they encounter an object. Examples of the two types of switches are shown below.

HFES Conference Part 5: Automation & Trust & Google Maps

During the conference I had a very personal experience with the effects of automation reliability on trust and subsequent behaviors.  First, a bit of background.  There is a large body of research examining how humans interact with automated systems (Global positioning systems, for example).  Human-automation interaction is quite complex; being affected by many factors.

Julian Sanchez (of MITRE) presented a poster at the conference summarizing the literature; presenting how the many variables of human-automation interaction relate to each other (figure 1).  One factor being extensively investigated is the issue of how much the user/operator (you & me) trusts the automation.

Figure 1. Conceptual Model of Human-Automation Interaction

I have used Google Maps on my phone extensively; and in the many cities I’ve used it, it has been a reliable tool for directions.  Since the phone includes a GPS chip, it can track my movements as I walk showing me my distance to my destination.  However, it failed miserably in San Antonio…twice.  First, I tried to find a restaurant near the River Walk and following the directions led me to go almost in the complete opposite direction.  I was so confident in Google we spent 20 minutes walking around until we asked a local policeman for directions. One reason I was confident was that as we walked toward our destination, the phone confirmed that our position was nearing the GPS destination.


The second failure was when we tried to find the Cowboy bar.  Automation researchers would say that I was complacent–I over-relied on the automation which indicted that my trust was not calibrated correctly.  My high level of trust came from thinking, “San Antonio is a big city, it must be fully and accurately mapped…” as well as past successful navigation attempts. This is one consequence of ultra-high reliability systems: the effect they have on users expectations and trust. Ever since my return, I’ve needed to use Google Maps (on the web or phone) and I have found myself very uncertain of the stated locations and directions offered by Google Maps.  I confirm Gmaps using the competing service (Bing Maps).

Sanchez, J.  (2009).  Conceptual model of human-automation interaction.  Proceedings of the Human Factors and Ergonomics Society 53rd Annual Meeting.

HFES Conference in San Antonio, Part 3 – Health/Internet…and ROBOTS!

One of my major interests at the moment is in the use of technological tools (primarily the Web) in the management of health.  So it was with great pleasure that there was so much research on this topic (I will mention more in future posts).

The first was presented in the Aging session (where Anne was program chair).  Jessie Chin and her co-authors were interested in a cognitive dilemma faced by older adults.  With increasing age, fluid cognitive abilities (those used in rapidly changing situations like working memory) decline with age.  These abilities seem particularly crucial when using the web as well as other tasks.  However, it is known that older adults often compensate for fluid ability declines by capitalizing on pre-existing knowledge (so called crystallized knowledge) which increases with age. (For an adequate and publicly available elaboration of the fluid/crystallized distinction, see the Wikipedia entry).

09AMlogoThe researchers examined the relationships between fluid and crystallized intelligence on illness knowledge in older adults (hypertension knowledge).  Consistent with their hypothesis, they critically found that illness knowledge (a form of crystallized intelligence gained through time) was a significant predictor of illness knowledge and that this knowledge may moderate the reduced fluid abilities.

Continue reading HFES Conference in San Antonio, Part 3 – Health/Internet…and ROBOTS!

Usability issues in navigating your life

BookGordon Bell, a Microsoft Researcher, is recording his life in excruciating detail in a project dubbed MyLifeBits:

Web sites he’s visited (221,173), photos taken (56,282), emails sent and received (156,041), docs written and read (18,883), phone conversations had (2,000), photos snapped by the SenseCam hanging around his neck (66,000), songs listened to (7,139), and videos taken by him (2,164).

Why is he doing this?  He sees some appeal in the ability to always remember:

By using e-memory as a surrogate for meat-based memory, he argues, we free our minds to engage in more creativity, learning, and innovation (sort of like Getting Things Done without all those darn Post-its).

In a work context, this is true.  A large part of my time is spent looking for files or trying to remember.

A whole slew of interesting human factors and usability questions are elephants in the room:

  • Currently, a portion of the recording is done manually.  How and what should be automated?
  • How does one efficiently search/browse through potentially petabytes of lifedata?  I don’t think a search engine would suffice (not all material would be textual).
  • This seems to solve the “encoding” problem in memory.  But it wreaks havoc with the “retrieval” portion.  You still need a good retrieval cue.
  • What are the implications of off-loading so much memory?  How will it change the way we currently learn/work?
  • As a type of automation, what will happen when it fails or is unreliable?
  • What are the privacy implications of recording this much data (especially the sensecam)?

His book outlining this idea comes out September 17th (Amazon link).

911! I’m Locked In My Car…Oh, Pull Lock? Thanks

19064136_200x150There must be a human factors angle here somewhere in this story.  Perhaps the consequences of automation leading to out of the loop syndrome?  Click through to the story to hear the 911 call.

KISSIMMEE, Fla. – A woman locked in her car in Kissimmee called 911 on Tuesday.

“It’s getting very hot in here, and I’m not feeling well,” the caller told the dispatcher.

The woman said nothing electrical was working, so her locks wouldn’t open.
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The dispatcher calmly told her to pull the lock up with her hand.

“Um, I’m sorry,” said the woman, who was not identified, after the lock opened.

And, no, officials say, this was not an early April Fool’s Day joke.

Consumer RFID technology–The Mirror by Violet

Violet has introduced an interesting computer peripheral called the Mirror that is an RFID reader for home users.  You apply RFID tags to everyday objects, program their actions, and when waved over the mirror, the actions are run from the computer.

When I first saw the following video, I was skeptical–their initial use cases in the video seemed silly.  But around 3:10 in the video, it starts to look really useful, especially for certain populations like older adults.  Imagine a tag on a medication bottle that tells you when you last took your medication and when you next need to take it.

[via Crunchgear]

“Smart” devices may help dementia sufferers remember to shut off stove, live at home longer

From Peter Squire (of The Daily Human Factor) another interesting story on using technology to support aging in place:

smarthome“The whole objective is to enable people to stay at home as long as they can,” says Bruce Carey-Smith, a BIME design engineer. The system reports the wealth of information it collects—from potential problems to successful interventions—to health care providers. “It’s about supporting—not about replacing—the role of care staff,” Carey-Smith says.

He says the system has been installed in the assisted-living residences of two U.K. dementia patients about a year ago—and both trials report good results.

In addition to reminding people to switch off potentially dangerous appliances (and actually shutting them off and contacting help if need be), the system is designed to help people avoid other hazards, such as nighttime wandering and incontinence issues. The system, for instance, senses when someone gets out of bed in the middle of the night and automatically turns on the bathroom light to help them find their way. Or, if the bed senses a prolonged nocturnal absence, the system will play voice recordings that gently remind people that, “it’s awfully late, perhaps you should be getting back to bed,” says Carey-Smith.

[Scientific American]

Lighting up the lives of the elderly – adaptively

From Peter Squire (of The Daily Human Factor):


Artificial light affects us in subtle ways. At its best, ambient lighting can relax, soothe or excite, but used poorly it can drain us of energy and disrupt sleep. What if lighting could adapt automatically to meet our individual needs?

The result, say a team of European researchers, would be an improvement in the general wellbeing of anybody who spends long periods in artificially lit buildings, particularly the elderly and the infirm, but also factory and office workers.

The system uses information from biosensors worn by the occupants of a room or building to determine what users are doing and then changes the lighting accordingly. The researchers’ goal is to use the technology to improve the wellbeing of the elderly, people suffering from age-related illnesses and people with reduced mobility, many of whom spend a lot of time confined indoors.

Click for more information and video.