Podcasting And Its Use In Learning

Podcasting And Its Use In Learning Systems
Hosna Tashakkori Hashemi,Professor Akbari
Information Technology Faculty
Amir Kabir University Of Iran, June 2008

Abstract
Podcasting is one of the most exciting and wonderfully disruptive technologies to emerge in recent history. It’s exciting because anybody can get involved, express themselves, exchange ideas, pitch their products. Whatever interests people have, there is a place for them in podcasting. With podcasting you don’t have to spend a lot of time finding what you want and waiting for it to download, instead by subscribing to the feeds you are interested to, they will come to you. The main advantages of podcasting which have made it a lot different from its predecessors are being automatic, easy to control, portable and it’s always available. Podcasts not only use the RSS feed to get the headlines but they can also achieve the files via podcatchers. Podcasts special features have brought the idea of using it as a supplemental material in learning systems. Capturing class lectures is one of these uses which has gained a lot of attention. Automated podcasting solutions expands the boundaries of classroom and have given the opportunity of education to people that can’t access it in other ways. Harvard and Washington universities are examples that are using podcasting as a learning material and have reached interesting results. In this paper we will be examining podcasting and it’s pace of evolution.

Introduction
A podcast is, essentially, an audio blog made from the RSS feed (Really Simple Syndication). You can listen to a podcast on a web page, in iTunes, or download it to an iPod. Some podcasts include video which are called vodcasts. Vodcasts or vlogs are a compressed form of a film which is compatible with the web. Podcasts are like a personal radio but the difference is that anyone around the world can access them at anytime he/she wishes. Podcast episodes are placed on a blog or website where people can subscribe to them. If any new episode will be available, subscribers will be informed via there podcast players (like iTunes). A very exciting feature of podcasting is its mobility, so people can transfer there podcasts on a mobile or an iPod and listen to them anytime anywhere like in the car or in the gym or while shopping .

RSS Feeds
RSS is a family of Web feed formats used to publish frequently updated content such as blog entries, news headlines, and podcasts in a standardized format. An RSS document (which is called a "feed" or "web feed" or "channel") contains either a summary of content from an associated web site or the full text. RSS makes it possible for people to keep up with web sites in an automated manner that can be piped into special programs or filtered displays.
The benefit of RSS is the aggregation of content from multiple Web sources in one place. RSS is a simple topic based pub-sub system, publishers publish their news by putting it into a RSS feed and providing a URL for it on their website. RSS content can be read using software called an "RSS reader", "feed reader" or an "aggregator", which can be web-based or desktop-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering the feed's link into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds and provides a user interface to monitor and read the feeds.
This is the feed that makes podcasting exist, the only difference between a RSS feed and a podcast is in the tag which shows the URL of the file that wants to be represented as podcast , with out this tag we will only have the title and headlines of a podcast but not the file.
With the expanding use of RSS feeds and podcasts, architectures have been mentioned for its use on mobile phones. There are two RSS readers for mobiles, the first is a client-side reader and the second is a web-based reader. In client-side readers, the user should install an application on his/her mobile and after that he/she can enter a RSS feed as an input and see the result which is synchronized with mobile devices. Web-based readers provide two complementary views, in the first view the user should add the feeds he/she likes with a personal computer and afterwards he/she can go to a special link and view the feeds he/she has picked, on her/his mobile device.

What Makes Podcasting Special?
You may think what has made podcasting so popular? We’ve had “Internet radio” on the web for over a decade. Yet the revolution never happened with these radios. All of them offer audio playback on demand via the web, but none has taken hold the way that podcasting has. Because nothing is interesting about sitting at your desk, waiting for a sound file to buffer—that is not much of a revolution. Many listeners, tired of waiting for the audio to finally sputter to life, ended up turning the radio back on and getting on with their lives. The main features that have made podcasting different from the others are being automatic, easy to control, portable and always available. Once you subscribe to a podcast, you don’t have to go looking after it, the podcatchers will bring it to you whenever there is any new episode and this is the meaning of being automatic. Subscribers can simply unsubscribe to any podcast when they no longer want to receive a show, so it’s pretty easy to control the podcasts. Also subscribing to podcast is anonymous so you don’t have to worry about
keeping your identity secure. At last, RSS essentially forms a “trusted channel” over an IP network so you can be sure everything you receive is exactly what the publisher has sent to you.

Creating the Feed
There is no need to right the whole feed of the podcast by hand. There are three ways to right them: using the automatic RSS creator, using stand-alone applications and using blogs to create the feed.
In the first solution, some websites and pieces of java code make the feed according to the ID3 tags in the MP3 file (ID3 is a metadata container most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, or other information about the file to be stored in the file itself). This is a good solution for people who want to create a podcast without spending much time but it has a lot of limitations such as limitation to include image or links to the podcast or changing the ID3 tags.
The second way to create a feed is using stand-alone applications which create resistant and good RSS feeds without using a blog. This is a good solution for traditional websites which don’t have blogs but the only problem is that you have to once update the site and once the feed.
The third way is using blogs. Blogs get the posts and make the feeds according to the posts automatically. This is the best way for creating feeds without any extra effort.
Required Tools for Podcasting
*1. Audio capture tools. Nothing will affect the quality of a podcast more than the tools selected to capture it with. A quality microphone is a good start, combined with audio software and a personal computer.
*2. Audio editing tools. There are numerous excellent audio editing tools available for all computer platforms.
*3. File transfer software. Once content files are created they need to be published to a Web site or blog using any traditional file transfer method; basic FTP/SFTP, HTTP upload, virtual drive (WebDAV), or server upload will all work well. Also the software that is used for Web site or blog creation will probably transfer the content files to the desired location as well.
*4. RSS Enclosures. Preparing the content for delivery requires it to be tagged via XML in a format known as RSS 2.0. The methods have been discussed before.
*5. Specialized RSS news reader. To automatically download the podcast requires a type of software called a RSS News Reader. It must be designed to specifically download podcasts to a specific folder on the subscriber’s computer or can be modified to do so.
*6. Content management software. There are a number of software tools that are available for managing podcasts or any other audio content. CMS software allows the user to sort and organize their content
into “playlists” which can be scheduled to automatically synchronize with a media player when you connect it to your computer or at specified times of the day.
*7. A digital music player. There are lots of choices of MP3 players to pick from.

Podcasting for Teaching and Learning
Podcasting allows students to use their technology-based entertainment systems (iPods, MP3 players) for educational experiences. Because students are already familiar with the underlying technology, podcasting broadens educational options in a nonthreatening and easily accessible manner. Podcasting is a fairly new endeavor, so there are relatively few formal evaluations of its educational value at this point in time. Most papers to date are optimistically speculative about the potential impact of podcasting on the quality of educational outcomes and experience, but a handful of authors are much more cautious about the expectations that certain types of podcasting might establish. Explorations of podcasting to date fall into three broad categories. The most commonly discussed is creating audio or video archives of classroom lectures. The second category of educational podcasting involves the delivery of supplemental course materials. Supplemental materials might include pre-recorded lectures that must be accessed in advance of class time, summaries highlighting important information, video reviews of homework problems, or relevant podcasts produced by a third party. Finally, many instructors have developed assignments that require students to produce and submit their own podcasts. This type of podcasting is most useful in classes where oral presentation and/or building technical competence in podcasting are closely related to course goals.
By using podcasting in educational systems, class resources can be available for students, education will not be limited to schools and universities and anyone with an Internet connection can access learning resources. Due to the mobility feature podcasting provides, students are not restricted to sit at their desks or behind their computers.
At the Harvard Extension School, the instructors of an introductory Computer Science course chose to make lecture podcasts available to the general public in addition to those enrolled in the course. At the beginning of the course, they published the RSS feed in the iTunes podcast directory and other online directories. By the course’s end, server logs suggested that the podcast had between 6,000 and 10,000 subscribers, with nearly 40% of those subscribers living outside the United States. From this study, we have learned that RSS subscription is a convenient way to download frequently published material, and its availability increases the likelihood that students will download audio/video lecture files. We have also learned that podcasting can extend the reach of educational institutions by making material accessible to those who might not otherwise have access. And we learned that dental students at the University of Michigan preferred audio only lecture files to other formats. But one of the most surprising findings from these studies—and the most consistently reported—is that a majority of students report using lecture podcasts at home or on a computer, rather than in a mobile environment with a portable device. The authors of these studies hypothesize about a range of possible causes for this behavior, but none included questions or observations that address the cause explicitly. It is significant that the majority of students access lecture podcasts at home or on their computers, given that mobility and flexibility are the predominant arguments for podcasting recorded lectures.
Objections to Lecture Podcasting
Primary among the objections to lecture podcasting is that the widespread availability of easily accessible lecture recordings justifies and excuses nonattendance at lectures. Despite the fact that studies have shown little or no impact on attendance when lecture recordings are made available on a class by-class basis, it is impossible to predict how lecture podcasting institution-wide will affect campus culture—particularly with regard to the perceived value of lecture attendance. Secondly, even if student performance is not adversely affected, there are concerns that the widespread availability of lecture podcasts removes the natural consequences of missing a class, like lessons of prioritization, organization, discipline, and personal responsibility.
Certainly, there are other more valid reasons to miss class, but many believe that the student should be responsible for proactively taking steps to discover what was missed. The student can make arrangements to have a friend record the lecture, seek out notes from a classmate, visit the instructor or TA during office hours, or any combination of the above. Not only do these steps place the responsibility for the student’s learning where it belongs (squarely on his or her own shoulders), but they arguably lead to higher quality learning resources and more engagement with peers and instructors.
Questions of attendance aside, many think that podcasting makes students reliant on materials that are intended as scaffolding or tools that are guiding the development of understanding. This objection is not really true either, because class lectures and presentation slides still play a much more important role for student than textbooks and other resources so students shouldn’t be avoided using them.
University of Washington’s Design for Podcasting Class Lectures
The University of Washington implemented a podcasting pilot program that began in Fall Quarter 2005 and gave students "any time, anywhere" options for reviewing those formerly analog recordings. The final podcasting pilot design uses Barix Instreamers as capture and encoding devices and a Debian Linux server for storage and publishing of digital audio files to a Classroom Portal.
The pilot grew from three courses in Fall 2005 to 20 courses in Spring 2006. At the start of Spring Quarter 2006, the pilot was extended to Health Sciences. By the middle of Spring Quarter 2006, the podcast lectures had been accessed over 50,000 times.
A key component of the podcasting solution is a device called a Barix Instreamer. The Instreamer is an inexpensive hardware device that provides reliable distribution of audio over a standard IP network. The Instreamer converts analog and digital audio into MP3 files which are then transmitted to a streaming server. This small, durable, low-power device has no fans or moving parts and eliminates the need to dedicate a computer solely to streaming.
In the system, the Instreamer is connected to the audio output on the PA rack. The Instreamer sends an MP3 audio stream via HTTP to our podcasting server, which can record the stream to a file. One Instreamer is required for each classroom, but one podcasting server can handle over 50 Instreamers.
The process of recording a class is as follows (see Figure below):
*1. Shortly before classes begin, each participating class is entered into the scheduling system. The class name, meeting days, location, start time, and duration are required.
*2. A blog with an integrated RSS feed is created for the class.
All of the next steps are performed automatically by the podcasting server.
*3. At the designated times, the podcasting server connects to the Instreamer and begins recording the MP3 stream to disc.
*4. At the end of a class, the podcasting server stops recording.
*5. Post-processing is done to the captured file. Postprocessing tasks includes error-checking, re-encoding to a lower bit rate, and adding ID3 tags to the file.
*6. Links to the finished MP3 file are added to the class blog via an XML-RPC request.
From the Classroom Portal, students can listen to the recordings directly on-line, or subscribe to the RSS feed for their class’s blog. Once subscribed to the podcast / RSS feed, students will automatically receive the latest lecture after it has been posted.
Recordings are typically available one to two minutes after the end of class.

Things to Consider For Future Podcasting
Podcasting is a very young technology and there is still a lot to examine about it. We still have to consider the infrastructures and architectures needed for class lectures, rights of the podcasts created, finding models of revenue from the podcasts and so on.
It has to be considered while one of the reasons for podcasting class lectures has been to expand the boundaries of education for people who can’t gain it in other ways, should there be pricing models for podcasts or not.
Causes and effects of lecture podcasting must be evaluated precisely and we have to check whether podcasting lectures really has an effect on the educational outcomes of students or not.
Effects on Current and Future Infrastructure
Both podcasting and VODcasting represent challenges to the current infrastructure albeit in different ways. The effects of these new technologies will be outlined for the following areas:
Bandwidth
In our current network environment a one hour audio segment will take about 1-2 minutes to download depending on network congestion. Because many podcasts are scheduled downloads, they can be scheduled for odd times of the day to reduce demand on the network.
Storage
We have to have enough storage place for all of the podcasts developed, specially on the servers of universities. Although the storage costs of this much valuable content are dropping dramatically,
the bigger cost may be in the cataloging, searching and retrieval of this information.
Because of its linear nature and data structure, it will be difficult, at best, to catalog the contents of these files without a significant effort. Most likely the files will be simply “meta-tagged” using the original editing or publishing software with generic informations such as: title, author, participants, subject, size, date, and select keywords. Actually tagging every subtopic and “time-coding” the tag for search purposes will be done on only the highest value content, or when currently nonexistent software appears that can automate the task with a certain level of reliability.
Supporting Hardware
Hardware requirements for podcasting are nominal. Any computer with an Internet connection and the ability of running Windows XP, Apple OS X, or Linux, has all the horsepower, storage, sound input/output, and memory required to create, edit, package and distribute a podcast. The only other equipment that is required is an external capture device with either an internal or external microphone. This includes both analog and digital recorders - analog recorders would require that captured content be transferred to digital format before editing and compression.
Supporting Software
The software specifically designed for podcasting is just beginning to appear. There are two types of software required - publishing and subscribing. Current publishing software needs both an audio capture application - like Win Amp, Audio Hijack Pro, or Audacity, and and RSS editing package that will create an RSS 2.0 enclosure and deliver it to a web site or blog for distribution site - like FeedForAll or FeedBurner.
Subscription software retrieves the specified content feeds, on-demand or on-schedule, and can place the content directly into the specified folder of a content management application like iTunes or Windows Media Player. These same applications allow synchronization of the podcast with the MP3 player or digital audio device.
Conclusion
Podcasting and its uses are developing everyday. Podcasting provides a lot of advantages and we have just reached the outer inner of its potential.
New uses have been developed which are positioned in a wide range starting from podcasting class lectures to developing intrabusiness communications to distributing new formats of audio and video.
Podcasting and Vodcasting definitions are not passing definitions and they are practical and real distributions of technology. The time shifting feature of podcasts comparing to the traditional models, has expanded the learning opportunities for students. The outcomes of learning systems that use podcasts depends extremely on the kind of use of the technology, not podcast by its inherent and it’s valuable only when it helps instructors and students reach their learning objectives.
The fast pace of podcasting evolution and its audio and video features which has been developing on mobiles and other handy devices, has made this technology very acceptable to people and specially students.
This technology needs a good bandwidth and a lot of storage place for contents so a centralized architecture has to be defined for it and also revenue models should be thought for it.

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