lectures on demand: delivering traditional lectures over the web
TRANSCRIPT
1
Lectures On DEmand:delivering traditional
lectures over the Web.
Marco RonchettiDip. Ingegneria e Scienza
dell'InformazioneUniversità di Trento
Italy
2
Lecture available on slidedshare
www.slideshare.com/ronchet
But beware!
Portability issue: some images missing because ppt was on a produced on a mac…
3
Video streaming
"Streaming" refers to video that plays while you are connected to the internet.
You don't need to wait for the entire file to download to your computer before you can start watching.
4
Bandwith
One hour of video encoded at 300 kbit/s (this is a typical broadband video for 2005 and it's usually encoded in a 320×240 pixels window size) will be:
(3,600 s · 300 kbit/s) / 8,388.608 = 128.7 MiB of storage
Modem users will not be able to view the higher bitrate streams (i.e., Cable/DSL or MPEG2).
5
We can watch TV on the Internet
Well, sort of…
QuickTime e unﾪ ( )decompressore TIFF LZW
' .sono necessari per visualizzare quest immagine
6
Coming from two perspectives…
Video on the Web Let's use it for teaching!
E-learning Let's use video!
Tech
nolog
y driv
en
Goal d
riven
7
What a great idea!
…really?
8
Teaching with videos?
Old idea (pre-web) Lectures on TV (1960…) Lectures on Videotapes (1980…)
COSTLY! Booooring… Unpractical Ineffective….
9
Teaching with videos?
Don't do it! Unless there is something new…
10
Let's not be so pessimistic…
What can we say from an
e-learning perspective?
11
What do we use e-learning for?
Help traditional students e.g. provide learning material on-line
Support remote students Make some activity faster
e.g. semi-automatically grading tests Change the way we teach
Make it more collaborative Create a business
Get new markets (e.g. Athabasca) Sell content (e.g. SCORM lectures)
12
Where can videos help?
Help traditional students e.g. provide learning material on-line
Support remote students Make some activity faster
e.g. semi-automatically grading tests Change the way we teach
Make it more collaborative Create a business - well, maybe…
Get new markets (e.g. Athabasca) Sell content (e.g. SCORM lectures)
13
Traditional and remote students: how?
Modern pedagogy says:
Traditional lecturing is dead.
The lecture model is under attack by people proposing learner centered learning
E-learning is an opportunity for a change
However…
14
Traditional and remote students: how?
… what is going on in your classroom?
At our place, we sometimes use a blended approach, much stuff is available through the net,
but the classroom is still there…
Can we make it any better, while the old paradigm still survives?
15
Breaking the space-temporal unit
Can we free the student from spatial and temporal constraints?
Classical solutions: Paper-based learning material (FernUniversitaet, OpenUniversity) VHS cassettes (and TV or satellite broadcasting)
New solution: Webcast - but is it different?
16
Teaching with videos?
COSTLY! Booooring… Unpractical Ineffective….
Well. Let's see…
17
But we just said videos are no good…
… unless something new is there….
18
Our experience
19
We started in late 2003
Using e-presence:A software developed at KMDI at University of
Toronto, Canada, mostly designed for synchronous webcasting of seminars
Focus on remote interaction
Today (the only?) PD software of this kind in sourceforge
20
e-presence today
ePresence Interactive Media is an Open Source Web Conferencing and Webcasting system that delivers video and synchronized presentation media over the internet using multiple streaming formats for multiple platforms. University of Toronto, Canada
http://sourceforge.net/project/showfiles.php?group_id=159579
21
What was different?
COSTLY! -> lectures are there anyway… Booooring… -> lectures are not synthetic Unpractical Ineffective…. -> let's see…
22
Cognitive interface
The main focus is on the projected slide, a clear voice is very important, the video carries additional information
like gestures, and can show the environment just enough
Navigation is possible
23
Logical Architecture
Synchronous (webcast)
Asynchronous (On line, or download - podcast)
Asynchronous(CD - DVD)
24
Our experience
Using e-presence we recorded in 1.5 years 9 university courses for a total of approx. 500 hours.
25
In our case (2004 data)
Connections available to our students: 77% standard 56K analog modem 22% some kind of fast connection
7% ISDN (128:256 K)15% ADSL (256K) 1% no connection at all.
(but some of the students with slow connection have friends with ADSL)
26
Student feedbackEnthusiastic. We were “forced” to
extend the experiment!
5%
63%
total 2nd exam (23 stud.)
1st exam(45 stud.)
students who…
4%6%…followed the course completely off-line
87%51%…used the system to review at least one lecture
75% anticipated using the system often or very often
27
Advantages from student’s perspective
Better time management:ability to recover lectures lost due to forced absence
(illness, work or other time-frame incompatibility);ability to better organize their time, deciding not to be
present at some lecture (elective absence); Better understanding
review some critical point (cases of poor understanding of a section due to concentration drop, excessive speed in an explanation or intrinsic difficulty);ability to check the correctness of notes taken during a
lecture;
28
Other advantages Miscellaneous
perception by the student of a better service provided by the university;support foreign (italian) students who might
have difficulties with the Italian (English) language;enrichment of the e-learning portfolio;possibility for the teacher to view himself;possibility to reuse lectures (across time, or
in different contexts!)
29
We learned that: Synchronous webcasting is not important Alternative distribution channels are
importantDownloadCD/DVD
30
Our requirements
the lectures should be easily browsed, with some form of indexing and a direct access to any time-location in the lecture;
lectures should be visible on all major platforms (Windows/Linux/Macintosh)
lectures should be available (in some form) also to students who do not have a large band Internet connection;
31
Our requirements
impact on lectures should be minimal;
production costs should be minimal, so as to allow scaling the approach to most courses.Operations must be simple (low level skills!)Post-processing operations must be light (i.e.
almost automatic), and not require much work
32
Our requirementsCognitive focus must be more
controllableIt must be also possible to use the
blackboard!Set-up must be lightweight!
agile and light setupeasy transportability
33
Our requirementsWe tried to push our requirements in the
e-presence development pipeline
We ended up writing our own software:Lectures On Demand
(Not because of NIS…)
34
LodeSupporto della didattica tradizionale
35
LODE: the user interface
36
Acquisition setup
QuickTime e unﾪ ( )decompressore TIFF LZW
' .sono necessari per visualizzare quest immagine
37
Acquisition - User interface
QuickTime e unﾪ ( )decompressore TIFF Non compresso
' .sono necessari per visualizzare quest immagine
38
System Architecture
OnStage WebServer
VideoStreamer
DVD
Browser
LODEacquisition
39
Portability (End user requirements)
Windows: Internet Explorer or Mozilla Firefox Java and Javascript must be enabled QuickTime plug in
Mac OsX: Mozilla Firefox Java and Javascript must be enabled QuickTime plug in
Linux: No QuickTime plug in available! Partial support
40
The system
1st version: Windows - Delphi. Problem: maintainability!
2nd version: Linux version (2003: acquisition - Ubuntu, postprocessing Fedora)
3rd version: moved to a Windows XP (2005) to have a more familiar environment (!). Acquisition and post processing can be done on the same machine.
4th version: client moved to Flash (!)
Available! But: not a product! Installation not simple!
41
New Flash version
QuickTime e unﾪ ( )decompressore TIFF LZW
' .sono necessari per visualizzare quest immagine
http://latemar.science.unitn.it/SSSW07/Gangemi-OntologyDesign/content/start.html
42
Lode - portabilitySupporto della didattica tradizionaleMac – Win - Linux
Player MP4(Video+audio,n
o slides)
43
Lode - portability
Supporto della didattica tradizionaleSymbian based phones
(Nokia N70)
Audio + slides+zoom
44
Is it really suitable for m-learning?
5 minute value: ability to use small fragments of time for learning Simplicity: limited display and input capabilities not practical
to transpose a power-point presentation on a PDA; Context dependent information:
location context; the system knows the location where the learner resides and adjusts to it;
temporal context; the system is aware of time dependent data; behavioral context; the system monitors the activities performed by
the learner and responds to them adjusting its behavior; interest specific context: the system modifies its behavior according
to the user’s preferences.
45
Is it really suitable for m-learning?
Yes, at the airport…Maybe, we are assessing students…
46
Extensions
Additional material attached to a point in the lecture…
Integration of (shared) annotation…Cut and sew to reflect TOPICS instead
of temporal organization…
47
Use
We recorded international Summer Schools in Europe and
Asia Courses and events at University of Trento We gave the system to University of
Innsbruck, Austria (not in use yet)
48
Assessing costs:
Equipment (easy)Running costs (this is what kills
projects!)
49
Assessing costs: initial costs:
Software acquisition(almost) 0 Euro (QuickTime, Java, Javascript, Darwin Streaming
Server, open source components, our sw + one non-free component)
Hardware acquisition:SERVER 1000 EuroACQUISITION STATION 1400-2400 Euro
1 Laptop (Euro 800-1500)1 Digital Camera (Euro 400)1 Radio Microphone (Euro 200-500)
50
Assessing costs: running costs setting up the system before lectures (10 min.) running the system during the lecture (2 hours) removing the system after lectures (5 minutes) starting the post-processing: 5 minutes. The post processing would
then go by itself for approx. 1 hours for producing a streams of 1 hour.
ending the post-processing (uploading the video on the web site, producing the master CD): 15 minutes.
35 minutes extra work for a 2 hours lecture
Network ?
51
Today: many other similar systems
EyAVideolectures.netWebinars of various sorts…
52
Some examples:
http://www.sciencelive.org/component/option,com_mediadb/task,play/idstr,CU-CSF-PC07-05_DarwinCorrespondence/vv,-2/Itemid,26Videolectures.net
http://sdu.ictp.it/eya/about/examples/roomD_2007.04.13_10.00-10.59/index.html http://videolectures.net/iswc07_pell_nlpsw/ http://epresence.kmdi.toronto.edu/Presentation/16
http://epresence.kmdi.toronto.edu/Presentation/193
53
Browser independence…
QuickTime e unﾪ ( )decompressore TIFF LZW
' .sono necessari per visualizzare quest immagine
54
Questions for you
55
Why do you need the video ?
Presence feelingVideo carries useful information (e.g.
gesture)Video carries essential information (e.g.
blackboard!)
=> Video or not, operator or not
56
Why do you need the slides ?
Slides carry essential informationSlides are only a help for the teacherYou need more than the slides…
(e.g. videos, live demos etc)
Capture screen (camtasia-like)?
Capture video signal (KMI - OU) ?
57
How important is format ?
Browser independence? Intranet solutions General audience
Network independence? Various resolutions Download Other means (DVD…)
Device independence? Mobile learning
58
How important is transportability ?
Higly optimized static settings?Light equipment?
59
Do you need temporal markers ?
To facilitate navigation? I guess yes, but… How do you create them? (image
recognition?)
60
Do you want to users to be able to give feedback/interaction ?
Lecture gradingGeneral annotationTemporally marked annotationReal time interaction (Synchronous
events)
61
Can you interfere with the teacher?
Many speakers do not like to be recorded
They do not want to be disturbedThey do not want to adapt (ppt vs latex,
macros in ppt, blackboard?)
62
When you'll have lots of stuff…
How will the users find their own way through? Semantic marking Access portal User evaluation/ranking Summaries Keywords Thematic catalogues
63
Be clear!
Define your goalsDefine your costsDefine your process
64
Can we do more?
Scenario:
Thousands of recorded lectures.
Can we dig in them to extract material for (less formal) learning?
65
Needle - search results
QuickTime e unﾪ ( )decompressore TIFF Non compresso
' .sono necessari per visualizzare quest immagine
66
Needle - architecture
ASR
Multimodal search!
67
Needle - ASR
We used 2 ASR:
-A) a speaker independent research system, used for transcriptions of the Italian parliament
-B) a commercial (dictation) system
-A) gave 60% word accuracy on sample-B) gave 76,6% word accuracy (after speaker training, in simulated environment)
-Why so bad? Mike, but not only…
68
Needle - Vocabulary
Research system vocabulary contained 62,879 words
Manual transcription contained 702 terms - 57 not present in vocabulary36 were technical termsRest was english or spanish words, company names, other minor stuff (re-…, diminutives).
Language model is important!We took Java books (11,443 terms before stemming - added to the vocabulary and decreased the unrecognized words from 8% to 3%)
69
ASR - is it good?
For information retrieval - yes.
Rare false positive on interesting domain!
70
Questions
Is it useful?
Is it effective?
71
Scenario100% accurate transcription (manually corrected)
Goal: extract some info from a 2 hour lecture in half of the time…
Assess whether the tool could reduce the learning time and help students in their learning task: we do not aim at claiming or proving that a course delivery mode is better than the other.
Comparing delivery modes (e.g. distance learning with traditional classroom-based instruction) (Sener 2005) for the purpose of establishing the superiority of one delivery mode over another is specious, irrelevant and counterproductive because there is not an uniformity of practice.
72
Experiment68 students, after 20 hours of a 50 hour Java course.
Group A: LODE
Group B: NEEDLE
73
ExperimentPre-Test: 5 questions, 5 minutes
LODE group: 70 minutes for the lecture, plus24 minutes for the post-test (8 questions): total 94 minutes to
accomplish the task
NEEDLE group: 48 minutes total for responding to the same 8 questions (50% of the time)
74
Pre-test results
75
Test results
76
AnalysisIn the subset of questions, which require students to have a
complete understanding of a part of the lecture both groups performed in the same way.
In answering those questions that also required some reasoning about concepts, group LODE – who had listened to the entire lecture – performed better.
In the questions where the students where asked to provide the right definition for a concept group NEEDLE performed better.
77
Further investigationsMultivariate regression:- no significant results
Clustering techniques- Indication that some feature seem to be present -
investigation is still on its way
78
Conclusion NEEDLE tool is more geared towards information
finding than towards actual learning.
A similar pattern could be reasonably expected in a similar experiment performed by reading some assigned material versus searching quick answer with Google.
However, our finding seems to show that Needle works very well as a tool for extracting information from a video source.