peter de moel - edu learn2010 part 2

Challenge the future

DelftUniversity ofTechnology

Navigation and searchingin recorded lectures

2Navigation and searching in recorded lectures

Personal details authors

Peter de MoelLecturer Drinking water Engineering /Project manager Pilot Delft

OpenCourseWareDelft University of Technology

(Netherlands)

Erwin de MoelMSc graduate Computer ScienceUniversity of Twente (Netherlands)

Jasper VerberkAssociate professor Drinking Water

EngineeringDelft University of Technology

(Netherlands)

Djoerd HiemstraAssociate professor Database TechnologyUniversity of Twente (Netherlands)

3Navigation and searching in recorded lectures

Expanding the use of recorded lectures

Backgrounds:• TU Delft OpenCourseWare • Recorded lectures at Delft and Twente (identical recording

systems)• Speech recognition for video searching in Twente

MSc project in Computer Science

http://www.citg.tudelft.nl/live/pagina.jsp?id=69192d7e-3eaf-4788-b936-21808aa8de29&lang=en

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Recorded lectures

Course size 1 lecture 30-40 lecturesRecording duration 15 minutes 100-120 minutesVideo resolution 340x240 (iPOD)

1920x1280 (HD)File location Streaming DownloadMovie content All-in-one video

Video + screenshots

Large variation

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Content

• What is in this course ? Lectures / Subject per lecture• What is in this lecture ? Subjects• How do I navigate ? Time slider or Table Of Content• Where starts the subject…..?• Where is something on ……..?

Main questions for students

6Navigation and searching in recorded lectures

Content of a course / lectures

• Overview of lectures• Text / pictures / pictures+text

Table of Content

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Content of a lecture

• Chapters and Paragraphs• Link to start time• Combined in ELS

Table of Content

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Content of a lectureInteractive Table of Content

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Content of a lecture

• Best sources: subtitles and speech recognition (over slides)

Tag clouds

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Content of a lecture

• Improvement by lecturer

Tag clouds

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SubtitelsAnd translated subtitles (online in YouTube)

http://www.youtube.com/watch?v=9na2hHJmmvE

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Subtitels

Mean word correctness 50% (range 25 – 75%)

Creation with speech recognition

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Meta data of lecturesCourse with 28 lectures (45 minutes)

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Collegerama lecture search

• Lecture titles • Slide titles

Table of content

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Collegerama lecture search

• Human made subtitles better than speech recognition• Slide content is not a good source for search engines• Multiple keyword result per slide: much shorter viewing

time

Search engine

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Presentation in ELSTOC – downloads – search engine

Challenge the future

DelftUniversity ofTechnology

http://ocw.tudelft.nlhttp://drinkwater.tudelft.nlcontact: p.j.demoel@tudelft.nl