Paul M. Fitts is widely regarded as the father of human factors. He gets mentioned a lot in HF texts because of his (still influential) law. In more modern times, Donald Norman gets a lot of recognition as the author of the Design of Everyday Things (mentioned in my post below) which introduced the idea of psychology and human factors to a more mainstream audience. However, someone who never gets mentioned (in my 12 years of education i’ve seen him mentioned once) was John E. Karlin who recently passed away.
By all accounts a modest man despite his variegated accomplishments (he had a doctorate in mathematical psychology, was trained in electrical engineering and had been a professional violinist), Mr. Karlin, who died on Jan. 28, at 94, was virtually unknown to the general public.
He is still relatively unknown to HF only because he rarely published his results; instead, he worked to solve problems in industry using the scientific method that all psychologists use.
“He was the one who introduced the notion that behavioral sciences could answer some questions about telephone design,” Ed Israelski, an engineer who worked under Mr. Karlin at Bell Labs in the 1970s, said in a telephone interview on Wednesday.
The NYT recently posted an obit detailing his contributions including such fundamental ones such as the telephone numeric layout (different from calculator layout):
Putting “1-2-3” on the pad’s top row instead of the bottom (the configuration used, then as now, on adding machines and calculators) was also born of Mr. Karlin’s group: they found it made for more accurate dialing.
The piece is very well written and I’m a little surprised that the author actually seems to understand HF and how it’s unique from other things (emphasis added):
It is not so much that Mr. Karlin trained midcentury Americans how to use the telephone. It is, rather, that by studying the psychological capabilities and limitations of ordinary people, he trained the telephone, then a rapidly proliferating but still fairly novel technology, to assume optimal form for use by midcentury Americans.
(NYT: great article but you hyphenated human factors in the 10th paragraph)
I held off for a while writing this post because I wanted to make sure I could include media Dr. John Senders included in his talk. I think you’ll agree it was worth the wait!
At the 2010 APA convention, John W. Senders, Ph.D. presented “One Thing at a Time: From Eye Fixations (1951), to Sampling (1954), to Information Theory (1955), to Workload (1959), to Queuing Theory (1964), to Attentional Demand (1966), Followed by a Lapse of 40 Years.” Video of the talk will eventually be posted on the Division 21 website.
Dr. Senders mentioned an eye tracking experiment from the 1950s, before any “eye trackers” existed. The method was to film the eyes of pilots as they scanned each instrument in a cockpit according to instruction. The position of the pilots eyes were coded in the close-up video. For example, a pilot might be told to “look at the altimeter,” and then the exact position of the pilot’s eyes was coded as “looking at altimeter.” Then, when the pilots were using their instruments naturally, a video of this use could be coded by eye position to know exactly when and where they were looking at any moment.
In another ingenious methodological development, Senders created a vision sampling device. The video below illustrates how it worked – a mechanical visor rose and fell in front of the driver’s eyes.
Dr. Senders came up with this idea of sampling while driving through a heavy rainstorm at different speeds, while the speed of the windshield wipers stayed the same. The visor in the video does the same — the rate of viewing can be controlled and the attentional demands of the driving task measured.
I’ve already covered these techniques in my classes as they are great demonstrations of creativity in research methods. If one has a well defined purpose and goal, a tool can often be created from surprising materials. Another example I often cite is the actual picture of Thorndike’s puzzle box — a splintered and rickety contraption that bears little resemblance to the finely drawn illustrations in intro psychology textbooks.
This post on Smashing Magazine about vertical navigation had me thinking about the book Anne and I are writing (manuscript due this Friday; panicking…I’m a 10 on the Wong-Baker scale). In one of the chapters I discuss tab navigation. When I was looking for a particularly bad example of the use of tabs I remembered Amazon’s website circa 2000. Fortunately, the Wayback Machine had preserved the travesty of UI navigation for posterity:
There is a grand total of 15 options and they are not really in alphabetical order (they seem to be grouped). Amazon can’t be blamed–we probably didn’t know as much as we know now (I can’t believe it was a decade ago!). But browsing the Wayback entry for Amazon’s homepage through the years certainly shows evolution and an iterative process to reach the current Amazon navigation scheme which eschews tabs almost entirely for a cascading, vertical navigation:
Do you have any examples of particularly good or bad examples of tab navigation?
Multi-touch technologies have a long history.To put it in perspective, the original work undertaken by my team was done in 1984, the same year that the first Macintosh computer was released, and we were not the first. Furthermore, there was a significant body of prior art on which multi-touch was built.
I went on a trip to Tucson over the holidays and toured the last Titan II missile silo. A brief history: from 1963-1982 these missiles were part of the cold war “peace through deterrance” and “assured mutual destruction.” In essence, they provided one reason not to attack the US: even were we destroyed, these missiles would still launch to destroy the Soviet Union.
Politics aside, the control room and interfaces for these missiles were fascinating from a human factors perspective. Gauges, buttons, and rotary inputs reside where we now would expect screens and keyboards. I reflected on this while there: though you need a button for each function, at least the interface never changes.
I snapped the picture below as an example of users improving a system. It appears they are trying to reduce their memory demands by listing on labels the upper and lower boundaries of these controls. It reminded me of the draft beer handles added to the levers in a nuclear power plant (as discussed by Don Norman in “The Design of Everyday Things.“)
A little more history: The Titan sites do not have a perfect safety record. With 54 sites operating for almost 40 years, there were 4 recorded accidents, all where lives were lost and one early fire where 53 people died. Fortunately, none of these accidents resulted in a nuclear explosion, not even in one where the nuclear piece of the missile was blown out of the silo. This site provides a list and engineering analysis of the accidents, and I would be interested in a human factors analysis.
In the accident that ejected the nuclear warhead, the commonly reported story says the explosion occurred when the missile was being serviced and a repairman dropped a heavy tool on the fuel tank. This implies the explosion was instant, however it actually occurred over 8 hours later, as the fuel exited the breech. The best description I could find comes from a newspaper, the Arkansas Leader:
The missile was housed in a silo within a silo that consisted of eight levels. Maintenance crews were working on level two when the accident happened. Attached to the hydraulic standing platforms was a rubberized boot that flipped over between the missile and the platform to prevent anything from falling through if dropped.
The day missile 374-7 exploded, the boot didn’t keep the socket from falling. At 6:30 p.m., maintenance crews entered the silo to begin work after being delayed due to various unrelated equipment malfunctions. The eight- and three-quarter-pound socket fell, hit the standing platform and bounced toward the missile.
The boot had become too pliable through the years, and the socket fell 70 feet down the silo, hit the thrust mount and bounced into the side of the stage one fuel tank. The 100,000-gallon fuel tank emptied into the bottom of the silo. The fuels interacted and generated heat, which in turn increased the pressure on the tanks. At 8 p.m., the wing made the decision to evacuate the control center.
“When we did that, we had no readings and no way of telling what was going on out there,” Gray said. “We lost all readings,” Gray added.
Many attempts were made to get into the control center to see the readings, according to Gray. At 3 a.m., two people, Living-ston and Sgt. Jack Kennedy, made it into the complex. “When they made it in and had to back out because the fuel was so concentrated they couldn’t see, there was some controversy on who told them to turn on exhaust fan 105,” Gray said.
What that did, according to Gray, was pull the heavy concentration of fuel into the equipment area with all the electrical pumps.
“And automatically, boom!” Gray said. “The fire flashed back into the silo, which already had tremendous heat in there, and when the fire flashed back, the stage one oxidizer tank that was already very, very high in pressure, erupted.”
Within one hour of the accident, Gray found the nuclear warhead intact. “It was cracked, but it pegged out on the radio-activity scanner,” Gray said.
Lessons learned from this accident brought about security improvements near nuclear weapons. Security measures to prevent accidents include: all workers wearing a belt with lanyards to attach tools to, a cloth on the platform to reduce the chance of tools bouncing off the platform if they do fall and a renovation of the platforms.
One of our tour guides had actually been stationed at the silo. He was a great guide and a living piece of history. Consistent with what you might expect, he said the hardest times to keep the missile running and protected were the down times, hours of vigilance and inactivity.
Last, I also photographed some of the operation manuals at the museum. Apologies for the fuzziness of these pictures, and I’ll re-type the best bits:
7. Key Run Up procedure, if required. (figure 3-26C)….Performed
Reference SACR 100-24, Volume VI to determine if key run up is required.
Step 8 can only be performed when SYNC indicator is lighted in NORM modes or TRACK/TRSHD indicators are lighted in SPCL modes.
8. DEMODULATOR CONTROL PRINT MODE thumbwheel switch ….. TEST
Observe printout on teleprinter. Printout is continuous series of characters RY’s or 64’s if transmitter site is transmitting idle message, or normal message traffic.
9. DEMODULATOR CONTROL PRINT MODE thumbwheel switch …Set as directed
*PVD must be continuously monitored visually or aurally.
*The PVD may be monitored by either a team in the silo or a crew member in the control center utilizing the wire type maintenance net.
For entry into launch duct level one, the PFC will be positioned outside of the opened level two launch duct access door, with sufficient probes to reach in the launch duct unless the PVD is required on level one of the launch duct for a sniff check.
Generally, I notice a large number of if/then/or/only types of commands.
I have only one last thing to say: the fact that Tucson, AZ, Damascus, AK and Wichita, KS are still around is a testament to the power of training and practice over our human frailties.
The chair has three upholstered pieces, each attached to a curved plywood shell. The larger one is the seat; the smaller two are back supports. All three are strategically angled to maximize your comfort. Charles and Ray Eames, the husband-and-wife design team behind the chair, had a remarkable understanding of ergonomic principles long before these were developed into a science in the 1970s.