1: USB release dates
USB (universal serial bus) was developed as an alternative to serial and parallel data transfer protocols. USB 1.0 was introduced in January 1996. As you can see in Table A, it has been a long time since the USB 2.0 specification was released.Table A
2: Changes in USB 3.0
USB 3.0 is one of the most anticipated changes to the PC in years. Here is a summary of the major changes:- SuperSpeed — New higher signaling rate of 5Gbps (625MB/sec)
- Dual-bus architecture — Low-Speed, Full-Speed, and High-Speed bus plus SuperSpeed bus
- Asynchronous instead of polled traffic flow
- Dual-simplex simultaneous bi-directional data flow for SuperSpeed instead of half-duplex unidirectional data flow
- Support for streaming
- Fast Sync –N-Go technology
- Support for higher power
- Better power management
3: The Low-Speed, Full-Speed, High-Speed and SuperSpeed confusion
There are four distinct data rates - not to be confused with the four USB specifications. Each new major USB specification introduced a new data rate. Table B shows USB data rate types supported by the four USB specifications. Each new USB specification has been backward compatible.Table B
Table C shows maximum data rates for the four data rate types.
Table C
USB 2.0 does not always mean High-Speed. This is usually, but not always, the case. A device labeled USB 2.0 can operate at Full-Speed instead of High-Speed.
Will this confusing labeling exist for USB 3.0? The USB 3.0 specification supports the three legacy speeds in addition to SuperSpeed. This is accomplished by referencing, not replacing, the USB 2.0 specification. Low-Speed, Full-Speed, and High-Speed devices are USB 2.0 compliant but not USB 3.0 compliant, so a USB High-Speed device should not be labeled as a USB 3.0 device. The USB Implementers Forum (USB-IF) has developed logos for each of the four data rates. Look for these logos when buying a USB device.
You can determine whether your USB 2.0 device is a High-Speed device in the Windows Device Manager (Figure A), although it is not a straightforward exercise. You will probably have to try more than one USB Root Hub before you find the device you are looking for.
Figure A
Open the Device Manager and expand the Universal Serial Bus controllers item. Open the Properties window for a USB Root Hub. Tip: Start at the bottom USB Root Hub.
Next, click the Power tab (Figure B). If the device is attached to this hub it will appear in the Attached Devices section. In this example, I have attached a flash drive and it is displayed as a USB Mass Storage Device. Note that this Root Hub has six ports available — one of them used by the USB Mass Storage Device.
Figure B
Finally, click the Advanced tab to see the USB speed (Figure C). On my system, the top six USB Root Hubs operate at Low-Speed and Full-Speed and the bottom two each operate at High-Speed.
Figure C
4: Actual data throughput
Actual data throughput is usually much less than the maximum advertised USB specification and is a function of many variables, including overhead. Actual throughput in practice is typically up to 35 - 40MB/sec for USB 2.0 and may exceed 400MB/sec for USB 3.0. NEC recently demonstrated its new USB 3.0 controller transferring 500MB in 4.4 seconds or “only” 113.6MB/sec. Symwave and MCCI claim to have demonstrated over 270MB/sec data throughput at the Intel Developer Forum in September 2009.Bottom line: Don’t expect actual SuperSpeed data rates approaching 400MB/sec anytime soon.
I have a USB flash drive that can read at 26MB/sec and write at 6.6MB/sec and is typical of flash drives available as of late 2009. These data rates are within the actual High-Speed data rate. But Faster USB 3.0 flash drives are on the way that can take advantage of the SuperSpeed data rate.
Most hard disk drives can transfer data faster than 40MB/sec. USB 3.0 will be welcomed by those who like to back up data to an external hard drive or SSD drive or who have any USB device that transfers large amounts of data.
5: Cabling and maximum cable length
During my days at Hughes Aircraft Company, I was always looking for ways to save money. I suggested that my supervisor, who sat in the next cube, share a laser printer with me. But printing over the long parallel cable caused characters to be intermittently printed as the gibberish that is so familiar when data loss or corruption occurs. USB cables have a similar constraint. But unlike my parallel cable problem, there is a solution.Table D shows the maximum cable and total lengths.
Table D
*The USB 3.0 spec does not detail a maximum cable length, but 3.0 meters or 9.8 feet has been recommended.
A total of six cables can be strung together using five hubs to achieve the maximum total length. In practice, the cable to the USB device counts as one of the six cables, reducing the maximum total length.If the USB 2.0 five-meter limit is not long enough for your needs, you can purchase one or more USB hubs or special cables. There are two types of hubs: powered and unpowered. Higher power draw devices may require a powered hub.
Longer total lengths can be realized using repeater extension cables and CAT5 extenders for USB 1.0, 1.1, and 2.0. There is also a special class of USB 3.0 cables that contain circuitry to achieve a length of six meters (19.7 ft). The USB-IF Web site recommends a USB bridge to achieve lengths greater than 30 meters.
The USB 2.0 specification for a Full-Speed/High-Speed cable calls for four wires, two for data and two for power, and a braided outer shield.
The USB 3.0 specification calls for a total of 10 wires plus a braided outer shield. Two wires are used for power. A single unshielded twisted pair (UTP) is used for High-Speed and lower data transfer and allows for backward compatibility.
Two shielded differential pairs (SDPs) have been added. Each SDP contains three wires, two for signal transmission and one drain wire. The two SDPs are used for transferring SuperSpeed data allowing for simultaneous bi-directional data flow.
See the Author’s Notes section at the end of the article for a reference to a USB 3.0 cable cross-section diagram.
6: Power
One of the most significant innovations in USB over serial and parallel protocols is the addition of power to the specification. Plug in a USB device and it can be powered from the host computer.To find the power requirements for USB devices open the Device Manager, expand the Universal Serial Bus controllers item, Right-click on Generic USB Hub as in this example or USB Root Hub (Figure B), select Properties and click the Power tab, as shown in Figure D.
Figure D
More power has been added in the USB 3.0 specification for power hungry devices. Table E shows the maximum amperage per port in milliamps.
Table E
There are four basic power states to accommodate a variety of devices and device states. For information about USB hubs and power, read Greg Shultz’s article Understand and exploit USB topology in Windows XP.
Note: The USB 3.0 specification details more power states, including idle and sleep.
7: Limitations
We’ve already discussed some of the USB limitations:- Maximum data rates
- Actual data throughput
- Cable length and total length
- Power
Though you will likely never find it an issue, there is a 127 device limitation per controller.
Each USB 2.0 Enhanced Host Controller Interface (EHCI) host controller has a 60MB/sec total bandwidth limitation, and the bandwidth is shared by all attached High-Speed USB devices. If, for example, two High-Speed devices like a digital video camera and an external hard drive are in use at the same time, the last High-Speed device attached may operate at a lower data rate or a USB Controller Bandwidth Exceeded error may occur. If you have two EHCI host controllers on your system, you may be able to resolve the bandwidth error by moving one of the High-Speed devices to another USB port. Wikipedia has a list of I/O Controller Hubs with two or more EHCI host controllers.
Want to know how much bandwidth has been allocated for each USB device in Windows? According to this MSDN article, you can check Device Manager, if you use Vista or later:
“Starting with Windows Vista, users can see how much bandwidth a USB controller has allocated by checking the controller’s properties in the Device Manager. Select the controller’s properties then look under the Advanced tab. This reading does not indicate how much bandwidth USB hubs have allocated for transaction translation.
“The Device Manager feature that reports the bandwidth usage of a USB controller does not work properly in Windows XP.”
Figure E shows that three USB devices have been allocated 4% of the bandwidth available for this Universal Host Controller. The Fujifilm FinePix S700 digital camera is a USB Full-Speed device and is therefore listed under one of the Universal Host Controllers and not one of the Enhanced Host Controllers. The USB specification defines four data transfer types: Control, Interrupt, Isochronous, and Bulk. The 10% System reserved value shown here is used for Control and Bulk data transfers and cannot be changed.
Figure E
During system boot-up and when a USB device is plugged in, a process called enumeration occurs. The device is recognized, its speed is identified, and a unique address is assigned. For devices using the Interrupt or Isochronous data transfer types, a specific amount of the remaining available bandwidth is requested, thus guaranteeing that the bandwidth will be available. If the bandwidth is available, it’s allocated, and the device description and reserved bandwidth will be listed on the Advanced tab.
Note: Don’t bother looking for the bandwidth used by a Mass Storage device like a flash drive. This class of USB device typically uses the Bulk data transfer type and is not listed on the Advanced tab.
In addition to any of the System Reserved bandwidth that may be available, devices using the Bulk data transfer mode may use the remaining non-reserved bandwidth. The Bandwidth Used column heading is misleading. The bandwidth is allocated/reserved but may not actually be used.
As you can see in Figure F, ICH9R Southbridge supports six Universal Host Controller Interface (UHCI) host controllers and two Enhanced Host Controller Interface (EHCI) host controllers. The number of UHCI and EHCI host controllers may be different on your system. The ICH9R supports a total of 12 USB ports. The six Universal Host Controllers operate at Low-Speed and Full-Speed and each shares its bandwidth with two USB ports. The two USB2 Enhanced Host Controllers operate at High-Speed and each shares its bandwidth with six USB ports. The Advanced tab shows that 20% of the bandwidth is reserved by each Enhanced Host Controller for Control and Bulk data transfers.
Figure F
Note: There is another host controller type, not shown, called USB Open Host Controller Interface (OHCI) that supports Low-Speed and Full-Speed devices. The name of the new Intel SuperSpeed host controller specification is Extensible Host Controller Interface (xHCI).
8: Connector and receptacle types
There are a number of USB 3.0 connector and receptacle types:- Standard-A connector and receptacle
- Standard-B connector and receptacle
- Powered-B connector and receptacle (new in USB 3.0)
- Micro-AB receptacle
- Micro-A connector
- Micro-B connector and receptacle
Table F
A new multi-tiered system has been developed for the extra pins needed for USB 3.0. The Standard-A connector is slightly longer and the receptacle slightly deeper to accommodate the new design. Five pins have been added to the Standard-A connector and receptacle specifically for SuperSpeed transmit and receive data and ground.
The USB 3.0 specification recommends using a blue color scheme for USB 3.0 Standard-A connectors and receptacles to distinguish them from USB 2.0 Standard-A connectors and receptacles.
The USB 3.0 specification includes a new type of connector and receptacle called a USB 3.0 Powered-B Connector and USB 3.0 Powered-B Receptacle. They are identical to the USB 3.0 Standard-B Connector and receptacle, except that two pins have been added for power and ground. It is designed to provide power to a USB device without the need for any other power source. The USB 3.0 Powered-B Receptacle can accept both Standard-B and Powered-B connectors.
The Micro family of connectors and receptacles are defined for handheld devices. Unlike the Standard-A connectors with their elegant design, the Micro connectors and receptacles have a more complex design with two plugs and receptacles sitting side by side — one for USB 2.0 and the other for USB 3.0.
See the Author’s Notes section for references to diagrams for the USB 3.0 Standard-A Connector, the USB 3.0 Standard-B Connector, and the USB 3.0 Micro Connector Family.
9: Hot-swappable devices and data corruption
I can’t write an article about USB without bringing up the issue of data corruption. Removing any USB device capable of writing data can cause data corruption if done improperly. There are three ways to minimize the risk of data corruption:- Verify write-back caching is off
- Pay attention to device LEDs
- Safely remove/eject device
Figure G
Next, click the Policies tab (Figure H). The Quick Removal (Default) option should be selected. If not, select it to reduce the risk of data corruption.
Figure H
Second, pay attention to device LEDs. Some USB devices will tell you when data is being transferred to or from the device with a flashing LED. Simply put, don’t remove the USB device when the LED is trying to tell you not to.
Third, safely remove/eject device. No doubt you already know how to safely remove a USB device but I am including it to be thorough. To safely remove a USB device in Windows 7, click the Taskbar Notification area Up-arrow and click on the USB icon (Figure I).
Figure I
Click the USB device you want to eject — Cruzer Micro, in this example (Figure J).
Figure J
The Safe To Remove Hardware notification balloon will appear when it is safe to remove your flash drive (Figure K).
Figure K
There is an alternate method for ejecting a USB device that you might not be familiar with. To safely remove a flash drive using Explorer, right-click on the logical drive assigned to the flash drive and select Eject from the drop-down list (Figure L). You can eject attached drives in Explorer, but be aware that more than one drive may need to be ejected.
10: USB downsides
USB can cause problems that can be difficult to debug. For example, on one occasion I was unable to install XP until I disconnected the USB to parallel cable attached to my printer.USB is so convenient and easy to use, it poses problems in the workplace. Flash drives are the biggest concern to IT managers. Flash drives are so small that they are easy to bring into the workplace in a pocket or purse. The flash drive is a conduit for sensitive or confidential data leaving the office or malware sneaking in.
In addition, people who are conscious of the risks of transferring viruses via a floppy, CD, or DVD don’t think twice about plugging in a flash drive and transferring files to/from home. Perhaps the best solution to this problem is education. Flash drives are banned in some government agencies and companies, though the effectiveness of that policy is questionable. Interestingly, the DOD is partially lifting its flash drive ban.
The final word
USB has been such a huge success that a more than 10 times improvement in speed and an 80% increase in power is almost certainly guaranteed to be just as successful, right? Well, maybe not. Intel’s original conceptual designs for the USB 3.0 cable specified optical fiber cabling to carry the SuperSpeed data. Copper replaced fiber optics in the final USB 3.0 spec, but Intel continues to work on a variation of this design known as Light Peak. It may be available as early as 2010 in Apple products before Intel plans to support USB 3.0 in its chipsets.Light Peak promises double the data rate of USB 3.0 now, with speeds possibly reaching 20 times the USB 3.0 speeds as the new technology matures. Perhaps more important in the short term, Light Peak cables may reach 100 meters (328 feet) in length and may be smaller in diameter and lighter.
Could Light Peak make its way to the Wintel platform? It certainly could, and its data transfer capability would leapfrog it past USB 3.0. So don’t bet just yet that USB 3.0 will be as successful as its predecessors. Regardless of what happens with Light Peak, USB SuperSpeed should satisfy USB device data rate requirements for many years to come.
Resources used in writing this article
- USB Implementers Forum
- Universal Serial Bus Revision 2.0 Specification (Zip, 10.2MB)
- Universal Serial Bus Revision 3.0 Specification (Zip, 3.8MB)
- Wikipedia - Universal Serial Bus
- Everything USB
- Windows USB FAQ: Introductory Level
- Beyond Logic - USB in a Nutshell - Making sense of the USB standard (PDF, 175KB)
Author’s notes
I would like to thank Microsoft for its invaluable help.In item 5, Cabling and maximum cable length, you will also need a USB switch and the appropriate USB cables if you are sharing a USB printer with two computers.
I wanted to include some of the USB-IF diagrams that showcased its new cable and connector designs. I also wanted to include its USB logos to show you what to look for when buying a High-Speed or SuperSpeed USB device. I was denied the use of all USB-IF diagrams. Here is a list of the images so you can look them up yourself if you so choose. They do a good job of detailing the changes you will see in USB 3.0 cables, connectors, and receptacles.
Items 5 and 8 — Cabling and maximum cable length and Connector and receptacle types:
From SuperSpeed_USB_DevCon_Physical_Heck.pdf (PDF, 2.33MB):
Page 11 — USB 3.0 Cable Assembly (Cable cross-section diagram)
Page 11 — USB 3.0 Cable Assembly (Type-A connector pin diagram)
Item 8 — Connector and receptacle types:
From SuperSpeed_USB_DevCon_Architecture_Overview_Dunstan.pdf (PDF, 3.15MB):
Page 9 — USB 3.0 Standard-A Connector
Page 10 — USB 3.0 Standard-B Connector
Page 11 — USB 3.0 Micro Connector Family
10 common user questions - and some analogies that help clear things up
Sometimes, the only way to help users grasp a tech concept is to throw them a lifeline to something they already understand. Here are some field-tested analogies from TechRepublic members.First, is the analogy going to work? Analogies attempt to explain an unfamiliar technical concept in more familiar terms, to explain an unknown in terms of something already known. So it’s vital that your audience actually knows the concept you regard as “more familiar” (Dcolbert). Explaining that programming a stack in memory is like using a Pez dispenser (Ccardimon) works brilliantly — unless the user has never seen one. Making an analogy to the library card catalog no longer works for younger audiences (Thordude).
Second, even if it’s a useful analogy, does your audience really want or need more explanation (Abegeman; Ian.Lockwood)? Or (worst case) are they going to think that you’re talking down to them (Mmparab)? Sometimes it’s wise to wait until they ask a question — or admit or demonstrate that they’re confused — before you trot out an analogy.
On the other hand, when the moment is right, nothing beats a good analogy. Here, then, culled from responses to Toni’s article, are 10 common user questions and some of the best analogies for answering them.
Note: This article is also available as a PDF download.
1: Why do I need disk space and RAM?
The most frequently used analogy for this topic is the desk and cabinet metaphor. Quoting Phil: “filing cabinet = hard drive space, desk size = RAM. Bigger desk = more files open to look at once. Smaller desk = lots of swapping files back to the filing cabinet.” And from Solutions: “Desk accessories (read: startup items like antivirus, update checkers, etc.) take up chunks of the desktop before you’ve even started working, leaving less desk surface for you to use for productivity.”Another analogy is the kitchen. Iago9999:”I explain that the cabinets hold the dishes you’re not using at the moment (hard drive) and the countertop is used for items you are using (memory). This also helps to explain the concept of virtual memory (moving stuff from the countertop to a separate cabinet).”
2: Why do I need more bandwidth?
Explaining bandwidth can be done with everyday hydraulics. Jbartoli: “I compare it to a water pipe and multiple people trying to take a shower.” Rouschkateer: “I use the multiple people to one milkshake analogy (many people don’t realize they share their bandwidth with their neighbors).”Traffic is another popular analogy. Nchetoora: “Bandwidth can be explained with the highway rush hour analogy … [or] everyone trying to rush out of a building at once when there is a fire drill.” Gater: “Some roads have more lanes than others, meaning that those roads have higher bandwidth.”
3: Why do I have to defragment my drive?
There isn’t a good real-life analog to defragmentation, but you can get close, Dave suggests it’s like “a library with all the books in a long row A, B, C, etc., and then as each book representing a program or service gets taken out it doesn’t get returned to its correct place. When you go to look for that book again you may find it, but will take longer to do …defrag puts them back in the correct order.”Going back to cooking, Betageek52 suggests you compare defrag to “… making a cake. If you put each of the ingredients used to make the cake in a different room, it will take forever to get it done because you have to run around the house for each one. Computers need all the pieces of a program together, so they can load it faster.”
Jdriggers: “I use the analogy of a pool table when explaining fragmentation and when it causes slowness. If I line up 15 balls in numerical order along the rail, how fast can you pick them up in numerical order? OK, now if I scatter them all over the table, how fast can you pick them up in numerical order?”
Analogy vs. explanation
To explain how things get fragmented as well as the need to defragment, MemphisGuy offers a simplified explanation, “purposely leaving out the stuff that causes their eyes to glaze, and using layman’s terms”:Let’s take the question, “Why do I have to defrag?” The answer is “You don’t. But let me tell you what it does. When you create your first document, life is good. When you create another document, the computer puts it right behind the first one, and so on. The computer doesn’t know how you may change any of these documents, so it doesn’t leave much space between any of them. When you go to edit or change the first document, if it can’t fit the change in the same place, it saves that part of the document somewhere else. That part is a fragment. If you go back and change that document many times, there will be many fragments. Suddenly, one day, you go to open that document and it takes a long time. It’s trying to go find all of the fragments” (at this point their eyes get big). “Windows treats its system files no differently from your documents. Everything eventually gets fragmented. Your entire system gets slower. Sometimes, you get errors or restarts for no reason. Now guess what Defrag does?” They all shout out, “IT PUTS THE PIECES BACK TOGETHER.” And then I say, “Then your system will run faster, programs may open quicker, etc.”To develop this simplified explanation, MemphisGuy repeated it until his eight-year-old child and a technically inept user both could understand it. (He suggests you could shorten the process by running it by a six-year-old instead.)
4: Why can’t I put everything on the desktop?
Jdclyde: “Everyone has a junk drawer, usually in their kitchen. Imagine EVERYTHING you own is in that one drawer. Get up in the morning, go to the junk drawer and look for some clean clothes. Time to eat … go to the junk drawer and try to find a spoon and bowl. You would never be able to find anything. We organize our computers the same way we organize our lives. If I want a pair of socks, I go to the bedroom (directory), go to the dresser (subdirectory), top drawer (subdirectory). If I want a spoon, I go to the kitchen (directory) and go to the drawer next to the sink (subdirectory).”5: Why is my Internet connection so slow?
When it comes time to explain networking or Internet problems, a natural analogy is to roads and traffic. NickNielsen likened an overburdened network to “a city street system built for the horse and buggy with dirt roads and no traffic controls. Unfortunately, we now have so many more cars than we had buggies, we are operating bumper-to-bumper. This causes a lot of wrecks (collisions!) that make everything even slower than the lack of signals justifies. Upgrading would replace those dirt roads with a fully paved four-lane grid system with a coordinated traffic signal.”Brennj4 suggests thinking of it this way: “A network is a series of roads (cables) joined at intersections (hubs, switches) and controlled by traffic cops and lights (routers). Cars (data packets) leave their homes (sender) and with their destination address in hand (IP address) they set on their way.”
6: Why does my graphic look so bad?
Often, it’s a question of DPI. Cfbandit has a good analogy for that: “I usually ask people what they know about Impressionist painting. Most have heard of at least Monet and know what I’m talking about. I then ask them what would happen if they made the brush strokes bigger. The usual reply is that the image would be even more blurry. I then ask them what would happen if they made the brush strokes smaller. They usually reply that the image would become clearer…. When they’re trying to get a high quality image of a 72 DPI Web photo, I tell them they’re trying to get a small stroke print of a big stroke picture. They’re usually okay with me showing them how to fix their ’stroke size’.”7: What about viruses and malware?
Subgeniusyeti offers analogies for both the problem and its solutions:- “The Path” — These are the safe places on the Internet. This includes the company site and various well-known news sites, etc. “You know when you’ve stepped off the path, and although you may not get any malware right away, it’s only a matter of time once you stray from the path.”
- “Pulling weeds” — This is the laborious process of removing malware from a computer, which may contain a number of hard-to-replace documents/programs.
- “Plowing under” - This refers to reformatting… guaranteed to fix it every time.
8: Network address? The computer’s right there
Real-life buildings are a fruitful source of analogies for network address concepts. For example, John explains the difference between static IP and DHCP: “It’s like the difference between a block of flats (apartment block) and a hotel. Each has many addresses (flats or rooms) but you only have a hotel room temporarily, whereas you have a flat (apartment) for a long time. What about a hotel guest who stays there for a long time? Well, that’s your reservations in DHCP.”Kalmano: “When explaining to students about domain names vs. complete URLs, I tell them that getting the domain name instead of the URL is like being invited to a party and being given the zip code instead of the full address.”
When it comes to explaining ports, Craigpower1 says, “The analogy I like to use to explain the relationship between IP addresses and port numbers is to say that the IP address is like the street address of an apartment building, and the port number is like the apartment number. The street address gets the ‘letter’ to the ‘building’ it needs to go to, and the port gets it to the specific apartment.”
As for security, Dprows adds, “An analogy I use to describe ports on a router is that the router is a big house with lots of doors. We leave the doors closed unless absolutely necessary, to keep intruders out.”
9: Why is fixing this going to take so long?
Sometimes, you have to explain the difference between an easy fix and a difficult fix. Techpartner offers this analogy: “I give the business the analogy of an organizational chart of a business, with departments, managers, directors, etc. Adding/removing employees from a department does not impact the whole company (easy bug fix). However, changing the reporting structure and introducing/removing a layer of management affects everyone (big bug fix).”Gitmo uses the analogy of a house: “If the fix involves some new nails in a couple of boards, we can do it quickly. But sometimes I have to jack the entire house up, lay a new foundation, and put the house back in place. That takes a long time, and we then have to make sure that lifting the house didn’t cause any problems elsewhere in the house…. Adding a basement to a house is an even bigger job.”
10: Why should I listen to you?
When users balk at taking advice from IT, an expertise analogy can help. ITCompGuy uses an auto mechanic analogy. “I explain that I have a key to start my car every day, but if the car runs slow or does not run at all, I rely on an auto mechanic because THAT is his expertise. You can replace auto mechanic with doctor, dentist, pilot, etc., but the important part is that everyone has a specialty.”Jay.Philbin, working for an HMO, likes to “compare the end user/PC to a patient (parent/child). When doctors would tell me simply ‘my PC doesn’t work’ and I asked for details, I often used to get remarks like ‘You’re the expert - you figure it out’ or ‘I don’t have time to deal with this.’
“If the moment seems right, I explain my position through their eyes as doctors and nurses. If a patient were to walk in and proclaim ‘I’m sick,’ the doctor would ask a series of questions to zero in on his patient’s malady. I ask the doctor how he would react to the patient saying ‘You’re the expert — you figure it out.’ This opens their eyes. I have to triage and diagnose in a way that’s similar to their routines. I’ve ended up with very cooperative end users over the years.”
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