Date: Fri, 02 Apr 2004 08:47:22 +0200

Author: Urs Lauterburg

Subject: Re: PRS again


Dear TAPlers,

First of all I want to thank John for donating his time to pass along
the information and his experience about what I believe to be a
problematic device. Are there any truly independent studies which
proof the effectiveness of a PRS? Is it possible to ''measure'' the
effectiveness at all?

Reading through John's report convinces me that to be conservative is
not necessary the worst. Fortunately our institutions has so far
retained from ''boosting'' the way we teach physics with this PRS
technology. To me it all seems to be more about creating dependencies
than enhancing the quality of education. It is a bit like the recent
hype of claiming the absolute necessity to connect schools to the
internet. Thinking that a more effective way to teach is merely
achieved by putting one of these ugly gray boxes somewhere in the
classroom is a myth. There is much more to it and being connected or
not is not so very relevant. The most effective thing is still the
tutor, his or her engagement, the capability to communicate and to
grasp the attention for a given subject. There is no way to replace
this capability with technology. In the best case technology can be
an aid and the issues of cost, functionality, maintenance and
durability has to be considered.

To me it seems as if the problem is more about being distracted from
the essential than about the lack of mental input. I dig the maxima
to reduce to the max. The attempt to sharpen our knowledge with this
strategy is exactly the aspect of physics which I like so much. It is
not possible to communicate this concept effectively through a
complicated piece of equipment. A performer cannot perform well if he
is distracted all the time by feedback, even if it is of high
quality. To keep things well separated is the most obvious and also
the most comprehensive approach. Emit the ideas and the content then
allow some time for interactive questioning and discussions
afterwards. KISS (Keep It Simple Stupid) is OK.

Again this is just my opinion and no universal law of nature


Urs Lauterburg
Physics demonstrator
LabVIEW wireworker
Physics Institute
University of Bern

>Jerry and Tappers,
>We use a different system than the Educue product, our system is H-ITT or
>Hyper Interactive Teaching Technology ( I have the system
>installed in a 350 seat auditorium and a 100 seat auditorium. H-ITT is
>working with Pearson Publishing House which includes Addison-Wesley,
>Benjamin Cummings, Allyn & Bacon, Longman, Prentice Hall and Custom
>Publishing divisions. I have also just recently talked with a
>representative from Brooks-Cole about the Educue system.
>One thing that I should mention is that there's some technical information
>that none of these manufacturers expressly acknowledge through the sales
>rep. Essentially all of these infrared SRS systems suffer from a problem
>called signal conflict (or some name like that...otherwise known as a
>log-jam), meaning that if two or more remote signals hit the receiver at
>the same time the system gets jammed and no signal gets recorded or only
>one. This causes the system to jam up and not record student answers. The
>receivers of these various systems all talk to the computer through a
>serial connection (USB or RS-232) and as such the systems can really only
>record one answer at any given moment in time unless you have multiple
>connections to the computer. Multiple connections helps to reduce the
>answer "log-jam" because the computers read speed is faster than the
>receivers signal speed. Also on the non-technical side, HOW THE INSTRUCTOR
>ASKS THE QUESTION can have a significant effect on whether system
>overloads occur leading to log-jams. If the question is very simple so the
>students have already figured out the answer before the instructor starts
>the clock in the software it can easily cause any system to jam.
>Essentially since the question was so simple all of the students hit the
>receiver at the same time as soon as the software is started....thus
>overloading it. If the same question was asked but the software was
>started BEFORE the question was shown.....student responses are naturally
>spread out over time and no log jam occurs.
>In the case of Educue verses H-ITT, Educue's sales rep claimed to be 5
>times faster than H-ITT and therefore needed "only 1 receiver for every
>100 students compared to H-ITT's 1 for every 25 to 40 students". Wrong.
>When I checked with Educue's technical support I learned it suffers from
>the same signal conflict / log-jamming problem. The net effect is that
>with more receivers attached to your computer on separate pathways (or
>chains of receivers) the better off you'll be and the faster the system
>will be. In addition, the length of time the remote transmits a signal
>effects how long the receiver chain is blocked by one student's answer.
>For example, the original H-ITT system used a remote signal time of 120
>msec, meaning the signal from one remote blocked all the receivers on a
>chain for 120 msec. The new H-ITT remote transmits a signal that's only 12
>msec long......10 times shorter.....thus making the overall system 10
>times faster. In addition, the old H-ITT remote's signal was a broader
>beam that would hit more than one receiver at a time while the new remotes
>12 msec signal is more focused and less likely to block other receivers.
>In my 350 seat main auditorium I currently have 16 receivers set up on 6
>different chains (or connections) to the same computer via usb hub. That
>means I can effectively receive about six responses at once. Of my 16
>receivers, 12 of them are the old style units and only 4 are the newer
>faster units. Eventually I'll have each receiver individually connected to
>the computer by a direct line and I'll transition completely to the newer
>faster units to further increase my recording speed. With our current
>system we regularly record 150 or more student responses in 1 minute. Our
>instructors usually give students 1:30 to 2 minutes to respond for class
>sizes of 250-300. Still....HOW the question is asked can still lead to
>As for the sales models for Educue and H-ITT......Brooks/Cole/Educue's
>sales rep was telling me that they "sell the remote bundled with the book"
>for something like $5 but then they charge the students $10-15 PER
>Originally the H-ITT remote was wholesale to our bookstore for $22.50
>which the bookstore turned around and sold for $30 with a buy back of $15.
>H-ITT's remote seems "more expensive" than Educue's right? Trick is the
>H-ITT remote does not need to be registered through the Educue/publisher's
>website for each class each semester for big $$$. The H-ITT system has a
>built-in email registration system so you can register your students
>yourself without charge. Here at the UF Physics Dept we decided not to use
>the H-ITT email registration system and instead built our own website for
>students to register on our main server. Piece of students by
>the remote one time, use it for several classes over their college career
>and then sell it back to the bookstore when they cost to
>student $15 for H-ITT vs Educue's charges per course per semester on top
>of the remote charge. And now that H-ITT's being bundled with Pearson
>Textbooks the remote is only $15 dollars as a one time cost and the
>bookstore will still buy it back! In my opinion this is a much better
>business model for the students. Of course the sales model they tell each
>school might differ but this has been my experience.
>H-ITT has also been VERY willing to listen to suggestions for how to
>improve their software and quickly implementing them. New versions of the
>software come out at least every 6-8 weeks if not sooner with better and
>better features added due to customer suggestions. I've personally had
>about 10 of my suggestions included in updated versions of the software.
>My suggestions ranged from minor fixes to major changes and H-ITT's done
>it. I've even got the programmers email address when I want to contact
>them. I'm extremely happy with the H-ITT system and I highly recommend it
>(no....I don't get any money from them to say this...:-).
>John Mocko
>Dept Physics, UF.
>On Thu, 1 Apr 2004, Jerry Hester wrote:
>> Tapplers,
>> For those of you who are running Personal Response Systems,
>> Have you developed in house software to integrate presentations and the
>> responses?
>> Have any of you used these systems for very large classes i.e. 300 - 500
>> students?
>> If you use it for this large of classes, do you run into delay problems
>> because of the time required for the system to receive this number of
>> responses?
>> We are currently planning to install the Educue PRS in our 500 seat
>> lecture hall. The Educue software seems very limited for presentation
>> aspects. We are looking at commercial software but it seems to either
>> be very expensive or limited to 250 transmitter max.
>> Many Thanks,
>> --
>> Jerry Hester
>> Laboratory/Lecture Demonstrations Coordinator
>> Department of Physics
>> Michigan Technological University
>> 1400 Townsend Drive
>> Houghton, MI 49931-1295
>> Phone: (906) 487-2273
>> Fax: (906) 487-2933
>John Mocko
>Senior Teaching Laboratory Specialist (Lecture Demonstrations)
>Department of Physics
>University of Florida
>Gainesville, Fl.
From Fri Apr 2 02:39:53 2004