Thursday, October 19, 2006

Dan Gross Knows the Most!

Hey, ya'll,

I figure I get permission to repost this here from the ed1vidconf posting today, on the grounds that Dan has taken my name in vain. Just kidding, but Dan's extensive posting makes for a good balanced read about the topic.

I will share that I had a great peer to peer connection via Skype (see the li'l movie there) that resulted in one of my 4th grade classes being able to chat for nearly an hour last week with a classmate who's in Holland with her family until January.

Cost of the experience? Zip. Quality, GE ("Good Enough"--thanks for the term Steve Bergen). And on the headset issue, I'd add that for that connection we used a Polycom Communicator (cost, 129 bucks from Polycom) and the student sitting in her (dimly lit) apartment in Holland rarely had to ask for repeated comments or questions and our students adjusted well and quickly to the sometimes skippy audio probably more created by our own bandwidth than anything else.

In short, Dan's right on most points. The downside of the dedicated equipment at this point is that you lose the chance of interacting with some sites who might not have it, like my student in Holland, whose parents use Skype to IVC with their research labs at Vanderbilt every day. A best-of-all-possible-worlds answer, I would submit, is to have both options. At least until the geniuses who do these things make all the solutions play fair and well with one another.

Dream on, Scotty.

Cheers, and heeeeeerrrrrre's DAN:

Posted by: "Gross, Daniel" owner_ed1vidconf Wed Oct 18, 2006 7:55 am (PST)

Susan Neale wrote:
Two districts in Nassau County, LI, have been using ViaVideo equipment for videoconferencing for a couple of years now. My experience: if you've got the bandwidth to support IP connections (a dedicated modem is a must in my humble opinion), the results are comparable to much more costly IP-capable equipment.

Good luck!

Susan Neale

Videoconferencing Program Consultant
New York Institute of Technology Central Islip, NY ***
Dan replies:
Since this came up again... (And no offense to Susan, but I want to make sure I nip this one before we let it spread.)

There are two issues here:

"webcams" or inexpensive software based codecs for videoconferencing

For the latter, most cable modem providers provide 4.5-6Mb download speed, but only about 300K upload speed. It is an asymetrical connection. Since h.323 connections use a balanced bandwidth model, you will find a 384K call is trying to cram more back to the provider than even your dedicated cable modem is likely capable of handling. YOU will get an OK picture quality, but it is likely that what you are sending back to the provider is jittery and freezes up, the audio may be tinny... And this holds true for any h.323 equipment - dedicated appliance or software based.

The first, which the original poster asked about, is if an inexpensive software based codec can be used in a classroom. You have to understand some of the tradeoffs:

You have to expose your computer to the outside world, or invest in firewall workarounds, or you will probably end up in a situation where you can only call out. This can be a problem if you're trying to work with someone else who can only call out. If you expose your machine to the outside world, you open to a wide variety of nasties.

Webcam hardware (typically) is not capable of full resolution video. Most use VFW QSIF/QCIF, approximately 1/4 of the resolution of the SIF/CIF resolution we normally use today. Also, vendors like Tandberg and Lifesize are pushing us to 4SIF/4CIF for motion. So webcams operate at 1/16 video resolution - again, this is what you're sending, not what you're receiving. Worse yet, most webcams will be shown on a higher resolution screen, causing extreme pixelation, where appliances "smooth" out the image on a lower resolution television, resulting in a more pleasing picture to the eye.)

Webcams often have a narrow depth of field, and with the exception of products like the Orbit, are not movable or zoomable. Everytime someone talks, they have to move into the field of view. Or a hand reaches up to cover the camera and move it, etc. Appliances are usually able to track to voices or presets, have deep focus fields, can be remote controlled.

Most soundcards and systems are not set up for full duplex audio, and certainly not high quality audio. Having a cheap headset is OK when you're using Skype peer to peer, but not so great when you have 25 4th graders all wanting to be heard.[See my comment in the intro above re Polycom Communicator--Scott] ViaVideos are a hybrid unit - for $400 or so, they offload the graphics processing from the CPU to the VV. But the hardware is now old designed around 1997, and the software has been supplanted by Polycom's PVX, which actually operates BETTER with a generic webcam than it does with a ViaVideo. (i.e. You really shouldn't be using your ViaVideo any more - a $40 webcam will do a better job. One such example is that although PVX can run h.264 with a webcam, it can only run h.263 on a VV.)

Jason's comments still hold true - the overall experience with a software codec/webcam is quite poor compared to that of a dedicated appliance. Having your students seen and heard is important, and a poor quality causes your presenting partner to burn out faster on your group. (Not something to brag about, but true none the less.) Yes, in a pinch, you can make it work. You can bring in a program, and make it look "OK" for your students. You will spend more time with IT setting up and maintaining a webcam based solution, versus a far more durable appliance that can be fired up and used quickly in a classroom.

Joan replied that in her district teachers use iSight for teacher to teacher work. This is ideal, and what it's designed for. Spontaneous 1:1 teacher to teacher or student to student collaboration. When teachers provide mentoring and remediation for individual students, this works well. Even those who really push the envelope of desktop IVC, like Scott Merrick, will tell you that you just can't get the same experience with a classroom in front of a webcam that you can with a dedicated appliance.

So a webcam is a good way to get started, but certainly not a very good long term solution. Appliances can be found used for a little over $1000. New and current hardware suitable for classrooms starts around $4000, up from $2600 a few years ago, but still just the cost of a few PC workstations. If your school did just 1 program per month over the course of a school year, you can depreciate the cost of that equipment quickly in just a year to $300 per use. That probably rivals your bus costs. Year two can be considered a free-bee. Use it more, and the cost per use comes down.

Webcams are wonderful - but they are what they are - for general instructional purposes, we strongly suggest that you pursue a dedicated appliance by any major manufacturer before you frustrate yourself with a cheap webcam...


Blogger Joan Roehre said...

There'll be NO living with him now!

9:42 AM  

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