A Podcast Service for the E-Learning Curve Blog

I'm delighted to launch a content delivery channel I've been researching and developing for a while: a podcast for the E-Learning Curve Blog.

First a little about podcasting...

A podcast is one in a series of digital media files (usually in either audio MP3 or video M4V format) that is released periodically and made available for download by means of web syndication.

This syndication aspect of the content delivery is what differentiates podcasts from other ways of accessing files, such as simple download or streaming. Special client software applications called RSS aggregators (also known colloquially as podcatchers) such as Apple iTunes or Nullsoft Winamp can automatically identify and retrieve new podcast files in a given series when they are made available, by accessing a centrally-maintained 'feed' that lists all files currently associated with that particular series.

New files can be downloaded automatically by the podcatcher and stored locally on the user's computer or other media device for offline use, enabling the audience to download content that is released episodically without having to manually check that new material has been made available.

According to the Horizon Report (2006) podcasting is

At the leading edge of a wave that will last for the next several years and beyond, personal broadcasting takes advantage of small, easy-to-use devices that people already carry to capture and share personal experiences, information, and events. This trend, which has roots in text-based media (personal websites and blogs), is expanding to include audio and video, as the tools for capturing and sharing those media become smaller and better. From podcasting to video blogging (vlogging), personal broadcasting is an increasingly popular trend that is impacting... audiences.

(p.11)

It's easy to see why podcasts have value in e-learning. Will Richardson states in Blogs, Wikis, Podcasts, and Other Powerful Web Tools for Classrooms that the

underlying technology here is digital recording and the idea that it is now very easy to create and publish these recordings... As long as you have a way to make the recording, and as as long as your students have access to the Internet, you can make this work.

(p.113)

Now that I have started publishing podcasts, I'm obviously going to write a series of articles about developing and delivering content using this learning channel. What's more, I will discuss podcast authoring using production techniques, based upon my experiences as a radio documentary maker in a 'previous life' - I'll be talking about the craft of writing for audio, as well as the technical aspects of the process.

Now, [drum roll] I want to introduce you to the E-Learning Curve's Other Podcast. This podcast service is about subjects that interest me other than e-learning. Topics I'll be covering include aviation, history and music, among others. The first set of podcasts is called Transatlantic: the Flying Boats of Foynes:

July 2009 is the 70th anniversary of the first scheduled trans-Atlantic airplane passenger service. Told against a backdrop of the momentous events of World War Two, this eight-part podcast documentary series by Michael Hanley tells the story of a unique era in world aviation.

Airlines like Pan American Airways (PAA) and the British Overseas Airways Corporation (BOAC) with their flying boats like the Short series of planes, and the massive Boeing 314 'Clippers' were welcomed to the seaport of Foynes, in the embrace of the River Shannon estuary on the Western edge of Europe. Come with me now as we fly back in time to the Golden Age of Aviation, a era of adventure, conflict - and the invention of Irish Coffee.

Parts 1 and 2 of the series are now available. You can listen and subscribe to each episode here, or you can access the podcast via iTunes. The next installment, The Glamour of Travel will be released on Tuesday July 28th, 2009.

The more observant among you will have noticed that this podcast channel is called the Other Podcast, which implies that there is a regular E-Learning Curve Podcast, discussing subjects associated with learning and development.

Yes there is. And it’s on it’s way soon. More about this closer to its launch.
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References:

The New Media Consortium (2006). 2006 Horizon Report. [Internet] Available from: http://www.nmc.org/pdf/2006_Horizon_Report.pdf Accessed 15 July 2009

Richardson, W. (2006) Blogs, Wikis, Podcasts, and Other Powerful Web Tools for Classrooms. Thousand Oaks, CA: Corwin Press.

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Streaming Digital Media for E-Learning 3: Using a Dedicated Media Server

According to Adobe, organizations use streaming media for corporate communications, electronic learning, and sales & marketing.

In a learning context, streaming media technology is a central component of

• Delivering remote presentations to employees, customers, and partners
• Delivering asynchronous (on-demand) just-in-time training
  Providing delta training to upskill workers
• Enhancing professional development via VLEs/PLEs and mentoring programs
• Capturing tacit knowledge from experts for distribution to their colleagues
• Conducting pre-sales demos
• Providing customer service

According to the eLearning Guild (Marks, 2002) e-learning using streaming media can save you money, increase learner participation, and improve motivation and focus (p.2).

So let's take a closer look at content delivery via a streaming media server. When using a streaming media server approach, the initial production, post-production, and content encoding steps are undertaken in the same manner as for progressive downloading and HTTP streaming. However, at the distribution stage, the compressed media file is placed on a specialized streaming media server. A Web page with a reference to the media file is placed on a regular HTTP server 'front end' web page .

The rest of the streaming media server delivery process differs significantly from the web server approach. In contrast to the HTTP/TCP methodology used in web server streaming, the digital media file data is actively and intelligently sent to the client. This means that the media server delivers the content at the data rate associated with the compressed audio and video streams. The server and the client communicated during the content delivery process, and the streaming media server can respond to any feedback from the client (see Figure 1).

Figure 1 UDP and RTP/RTSP protocols

While streaming media servers can use the HTTP/TCP protocols used by Web servers, they can also use specialized protocols such as the User Datagram Protocol (UDP) and Real Time Streaming Protocol (RTSP) to greatly enhance the quality of the streamed content and ultimately the users' media access experience.

UDP is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages called datagrams to other hosts on an Internet Protocol (IP) network without requiring prior communications to set up special transmission channels or data paths.

Unlike TCP, UDP is a fast, lightweight protocol. This makes UDP an ideal protocol for transmitting real-time digital media data, which can tolerate some lost packets. Instead of the blind retransmission scheme employed by TCP, streaming media servers' resend feature ensures that the server only retransmits lost packets that can be sent to the client in time to get played.

Like UDP, the Real Time Streaming Protocol (RTSP) takes advantage of streaming by breaking data into many packets, sized according to the bandwidth available between client and server. When enough packets have been received by the client, the user's software can begin viewing the content: typically one packet is played, while subsequent packets are decompressed and downloaded. The advantage of RTSP is that it enables the user to start viewing multimedia content almost immediately. Both live data feeds and stored clips can be used as the sources of the content. The transmission of streaming data itself is not a task of the RTSP protocol; most RTSP servers use the Real-time Transport Protocol (RTP) for media stream delivery, though some vendors implement proprietary transport protocols. The RTSP server from adobe Systems, for example, also features their proprietary RTMP stream transport protocol.

RTSP has been called a "network remote control" for multimedia servers, in that the user can typically play, pause, rewind, scrub through (rewind and fast-forward), record, and stop playback via client interactions with the streaming server. Examples of media server products using this approach include:

• Flash Media Server family
• Microsoft Windows Media Services
• Apple Darwin Streaming Server
• RealMedia Helix Server

In a sense, RTSP is more of a framework than a protocol. It's meant to control multiple delivery sessions, provide a way to choose delivery channels such as UDP, TCP and IP-multicast. The delivery mechanisms are based solely on RTP. RTSP has been designed sit on top of RTP to facilitate both control and synchronous delivery of content.
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References:

Adobe Dynamics Group (2001). A Streaming Media Primer. [Internet] Available from: http://www.adobe.com/products/aftereffects/pdfs/AdobeStr.pdf Accessed 4 July 2009

Marks, R.B. (2002). Learning Styles and Streaming Media. The eLearning Developers Journal, October. [Internet] Available from: http://www.elearningguild.com/articles/abstracts/index.cfm?id=43&action=viewonly [Subscription Required). Accessed 3 July 2009.

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Streaming Digital Media for E-Learning 2: Delivering Content via a Web Server

Deploying streaming media content with the web server approach is very similar to the download-and-play model I described in yesterday's post: it's a pull technology.

Using this paradigm, the initial request for data originates from the client, and then is responded to by the server. When using digital media, uncompressed audio and video is first compressed into a single, muxed (multiplexed) media file for delivery over the Internet or a network at a specific bit rate. The media file is then placed on a regular web server. A web page containing the media file's URL is also created and placed on the same web server. When the link on the web page is clicked on, a client-side player (such a Windows Media Player or QuickTime Player) downloads and plays the requested media file.

In the context of e-learning, it's pretty standard for a video demo (for example) to be stored and progressively streamed from a Moodle LMS running on an Apache such as Apache server (see Figure 1)

Figure 1. Demonstration: Uploading a WMV file to Moodle, and playback via HTTP streaming in Windows Media Player
[Click to play the demo]

From a user's perspective, this process looks and feels identical a download-and-play case use case. From a technical point of view, the difference lies in how the client functions.

Unlike the download-and-play model, the client player starts actually starts playing the streamed digital media file while it's being downloaded. This is possible because the content is cached: a process of collecting the first part of a media file before playing. This small 'buffer' of information allows the content to continue playing even during periods of high network congestion. With this delivery method, the client retrieves data as fast as the Web server, network and client will allow, regardless of the quality of the compressed stream. Only certain media file formats support this type of progressive playback including Microsoft's Windows Media format (WMV) and Apple's QuickTime (MOV).

Web server streaming uses the Hyper Text Transport Protocol (HTTP), the standard Web protocol used by all Web servers and Web browsers for communication between the server and the client. HTTP operates on top of the Transmission Control Protocol (TCP), which handles all the data transfers.

It's useful to remember that HTTP/TCP is optimized for asynchronous, static applications, such as displaying static Web pages, and file transfer; this can affect the distribution and delivery of motion-based, asynchronous ('on-demand') content. Users may experience interruptions, 'glitches,' and temporary loss of playback because to the limitations of the HTTP and TCP protocols when handling multimedia content.

More...

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Streaming Media for E-Learning: A Primer

I'm preparing a series of blog articles on the topic E-Learning Using Collaboration Platforms. In the series I will discuss:

• Collaboration Platform Technology
• Synchronous Delivery
• Asynchronous Delivery
  
• Overview of Products on the Market
  
• Production Considerations
  
• What works (and what doesn't work)
  
• The Online Instructor
  
• Mentoring
• Integrating Collaboration Solutions and Other E-Learning Channels

This is an area of technology in education that I'm especially interested in, so I'm really looking forward to bringing this set of blog posts to you here on the E-Learning Curve Blog. As the series is still under development, there's an opportunity to request an article on an aspect of this topic that you might like to see covered: let me know and I'll see what I can do.

In the meantime, I thought I'd give you a 'heads up' by discussing some of the fundamentals surrounding using collaboration solutions: streaming media.

Until about five years ago, Web-based audio and video - or digital - media was primarily a download-and-play technology. Users had to download an entire media file before it could be played back. If you're over 30, you'll remember those postage stamp-sized video clips (usually in ASF or MOV format) that took forever to load over your dial-up connection (and were hardly worth the wait). Because digital media files are usually very large and take a long time to download, the only content found on the Web was short, low motion clips. Even these files could take 20 minutes or longer to download.

How video used to look and sound – Marc J. Rosenberg discusses personalized learning
[Click to play video]

With the increasing availability of high-speed internet access, streaming digital media has become more prevalent. In the consumer market, this has led to the rise in popularity of services like YouTube, and the current emergence of video-on-demand (VOD) solutions like Hulu, as well as ustream and for lifecasting and live video streaming of events online.

Streaming media works almost instantaneously: other than a short delay before the requested file starts to play, you don't have to wait to start watching, no matter if the file lasts thirty seconds or thirty minutes in duration.

Broadly speaking, there are two way of delivering streaming digital media content over the Web. The first method uses a standard HTTP Web server to deliver the audio and video data to a media player. The second approach uses a separate streaming media server designed specifically to stream digital media. Using a streaming server is more efficient and flexible, provides a better user experience, and is more secure than HTTP streaming.

Both approaches have their advantages and disadvantages, and I will begin to look at these tomorrow.

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Shooting Video for E-Learning Use – eLearning Guild

I recently posted on integrating audio with e-learning authoring tools, and in the near future, I’ll be covering some aspects of the visual aspects of creating e-learning content, focusing on creating video for application demonstrations and using still imagery in e-learning.

In the meantime, the eLearning Guild have just published an informative primer called Making a Demonstration Video for E-Learning Use.

The article in Learning Solutions e-Magazine discusses a favorite of mine: straight-forward ‘How-to’ video demonstrations. The authors, Steve Haskin and Tim Martin describe this learning modality:

“How-to” instruction is an important training modality; in fact, “learning how to do things” is the cornerstone of being human. Our lives are spent learning how to do things, and this doesn’t stop simply because we “learn” in the workplace or even when we slip the “e-” in front of learning.

(p.2)

In this context then, tasks and activities can be elucidated using a number of video based approaches including:

• Sequenced still images
• Video
• 3-D animation

Video photography is basically light captured on a medium like film, video tape, or DVD. However, lighting a subject properly is something of a black art and if done poorly will undermine the learners’ ability to interact with the subject matter. The article’s authors discuss the basics of lighting in reasonably good detail, including key-, fill-, and back lighting, as well as color temperature, and new lighting technologies like fluorescent and LED light types.

They go on to describe the importance of a good tripod, and what you should look for in a video camera. I would agree with their assertion that HD cameras “are complete overkill” (p.7) and in fact that good old reliable MiniDV digital tape is still the best video media choice for e-learning practitioners – your content is captured as uncompressed DV-AVI video (so it can be edited and rendered in either NTSC or PAL as well as in various compressed formats), and MiniDV is a great archive format.

The authors conclude by discussing the pros and cons of various video codecs, their benefits and disadvantages.

Video can seem technical, overly-involved, and even intimidating to the novice videographer: I suggest that you have a look at the article if you want a good introduction to video for e-learning and if you want to know your blondes from your redheads. (They’re types of light: I wasn’t being rude!)

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References:

Haskin, S., Martin, T. (2009) Making a Demonstration Video for E-Learning Use. Learning Solutions e-Magazine [Internet] Available from: http://www.elearningguild.com/articles/abstracts/index.cfm?id=302&action=viewonly Accessed 30 March 2009

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