An Investigation of the Potential for Accessible Vodcasting of Learning Objects

Voula Gkatzidou, Dr Elaine Pearson, Christopher Bailey, School of Computing, University of Teesside; The Subject Centre for Information and Computer Sciences.

Introduction

Most educators recognise the need to diversify the way their learning and teaching activities are delivered to students. New technologies and techniques are being explored as a means of providing that flexibility, but understanding how this technology works and what one might do with it is a little more challenging (Manning, 2005). Pod and vodcasting are increasingly being used to deliver educational content to students.

If effectively deployed, podcasts could offer a way to enhance student’s learning experiences and deepen levels of learners’ engagement and collaboration (Boulos et al, 2006). Empirical research is needed in order to build up pedagogical evidence about the use of vodcasts in the educational context and their potential in terms of accessibility is largely unexplored. This project aims to investigate the viability of using portable media players as a learning tool and this case study reports on the results of our initial work.

Background to the Project

This project aimed to investigate the potential for accessible vodcasting and explore the requirements for creating adaptable learning objects that could be delivered in an accessible format on a portable video media player.

Two portable media players have been used during the project; the Apple Video iPod and the Creative Zen Vision M, both of which have a capacity of 30GB and support a variety of different file formats.

This work is part of a larger research project in collaboration with the Learning Technology Research Institute (LTRI) at London Metropolitan University, which has carried out considerable work in the field of learning objects, placing a pedagogical emphasis on the design and development of multimedia learning material. The LTRI has developed a number of award winning learning objects and their successful use is well documented as part of innovative blended learning approaches to the teaching of programming to first year Computing students (Boyle et al., 2003).

Methodology

The preliminary stages of the project involved analysing the existing learning objects which had been developed by LTRI. Particular emphasis was placed on examining the navigation, interactivity, design and content. Once this had been completed, the adaptations which the leaning object required were defined. The learning objects were then redeveloped taking into account the technical considerations of the portable media players. Once these had been completed, converted to an appropriate format and loaded onto the portable devices, they were evaluated with students. This evaluation process consisted of structured interviews on an individual basis with participants. The results of this study will contribute towards our research work on developing tools for the creation of adaptable learning objects.

Learning Objects Adaptations

Before adaptations could take place the content and structure of the existing learning object was analysed in order understand the underlying pedagogy.

Analysis of sample learning materials

The learning object that will be analysed and adapted for this vodcast is designed and developed by the London Metropolitan University as part of a project which aimed to improve pass rates and retention in Introductory Programming. The learning objects were originally designed for web delivery and have also been adapted for PDAs.

The learning objects were authored in Macromedia Flash and are short, self contained resources that focus on one small learning objective or topic and explain the often abstract key programming concepts that students find difficult to comprehend. The learning objects were designed to be interactive, engaging and easy to understand (Bradley et al., 2005). A number of multimedia techniques were employed to engage the students in the subject matter and to help them understand these complex and abstract programming concepts, such as animations and interactive simulations to provide visual examples of Java concepts and program code (Bradley & Boyle, 2004). This work culminated in the achievement of a European Academic Software Award (EASA) in 2004.

For the purpose of this project we have chosen to use the ‘While Loop’ learning object (Figure One) which is typical of the multimedia objects. The subject matter involves the notion of ‘repetition’ which is illustrated by using repeated actions to move an object across the screen. Familiar objects are chosen and they are animated to illustrate the concept, for example, a hammer repeatedly knocking in a nail (Boyle, 1997).

Figure One: A screen from the ‘While loops’ original learning object

The visual examples are accompanied by the programming code that would be used to re-create each sequence in Java. The programming code is broken down into step by step sequences. The While loop learning object consists of an Introductory page, three pages with examples and an interactive quiz at the end.

For the purpose of this project, we have used the PDA version of the ‘While Loop’ learning object (Figure Two).

Figure Two: A screen from the ‘While loops’ learning object for the PDA

The reason for this was that in the PDA version of the learning object, most of the explanatory text is replaced with audio commentaries, alleviating potential problems of screen overcrowding, text legibility and readability. Animations were reduced in scale, and details were simplified to retain clarity. Buttons for the audio explanations replaced the text on each screen. Some of the interactive elements were changed from the original web based learning object to suit the ‘point and click’ method of user control on the PDA but the fundamental goals of the task were not changed and the underlying pedagogy was not compromised (Bradley et al., 2005).

The following section will document the adaptations that were required in order for the PDA While Loop learning object to be accessed and used on a video media player.

Format compatibility

The current generation of portable media players do not support Flash movies. Therefore it was necessary to convert the Flash movie learning object into a format which is compatible with the media players. Although Macromedia Flash has the capability to export to .AVI format, we encountered compatibility problems when using QuickTime. The video iPod and the Creative Zen media players support a number of different formats; the only file format which is support by both is MPEG-4.

Before the captioning process could begin, the separate Flash movies had to be converted into a video format such as AVI or MPEG. A piece of dedicated software, AMOR SWF to Video Converter, was used to achieve this. The functionality of QuickTime Pro was then used to combine the four separate parts of the While loop vodcast into a single movie.

Figure 3: Actual size of vodcast displayed in iPod

Figure 3: Actual size of vodcast displayed in iPod

Figure Three: Actual size of vodcast displayed in iPod

Design Adaptations

Since the While loop learning object had already been adapted to a PDA version the number of design adaptations required for viewing on a portable media player were small. The screen layout remained similar, the only content which was changed were the navigation buttons which were removed, and the title ‘While Loop’ and progress indicator were moved from the bottom to the top of the screen to accommodate captioning at the bottom for the caption version.

The screen size of the PDA is larger than that of the portable media players, both the IPod and the Creative Zen screens measure 2.5 inches diagonally.

When using Flash to adapt the learning object, the canvas size was changed to match the screen size of the portable media player.

Figure Four: The vodcast hammer example

Pedagogical Adaptations

Navigation of the PDA version of the learning object was facilitated through buttons activated by the devices touch screen. Neither of the portable media players used in the study features a touch screen. As a result, interactive elements of the PDA learning objects would be unusable on the portable media players. This has a significant impact on the pedagogy of the learning object when considering factors such as navigation, which the user would have limited control over. A navigation mechanism could not be provided through the learning object itself, but the user could still use the general controls built into the device, such as play, pause and stop.

The PDA version contained an interactive quiz. This took the form of an activity which required the user to construct an example While loop by selecting lines of code in the correct order. Audio feedback was given after each selection. The removal of the quiz element has implications in that the student does not have the opportunity to test or reinforce their learning. The inclusion of a quiz in some form was examined, but it was decided it could not be effectively implemented without support for interaction within the timescale of this project.

The implications of this were that a previously interactive learning object, the delivery of which could be controlled by the user, would be converted into a linear, movie which would be viewed as a single entity. Changing the pedagogy in this way may impact on the effectiveness of the learning object in terms of usefulness of the learning objects to the students. To ensure the learning object was as effective as possible, consideration was given to the appropriate sequencing of the individual elements of the learning objects.

The original learning object contained a number of separate elements; there were instances where audio, text and animation where all active simultaneously. In many cases, these elements were related, for example, the audio would describe code which was currently being highlighted on the screen. Initially, the possibility of separating some of these elements was discussed, such as splitting text elements up into a number of screens. Considering the context of the learning object (its aim being to demonstrate coding techniques), it was decided that as long as the text was readable on screen no changes would be made.

Captioning

Captions are text versions of the spoken word in audio or video media files. In order to increase the accessibility of the While loop vodcast the potential to use captions to supplement the audio content was explored. The inclusion of captions may benefit specific user groups, such as those who are deaf or hard of hearing and to a lesser extent, those whose first language is not English.
Common web accessibility guidelines indicate that captions should be:

Synchronized - the text content should appear at approximately the same time that audio would be available
Equivalent - content provided in captions should be equivalent to that of the spoken word
Accessible - caption content should be readily accessible and available to those who need it

On the web, captions can be provided through multimedia players such as QuickTime, Real Player, or Windows Media Player; however the considerations are different when viewing vodcasts on portable media players as no such software is used.

Captioning Techniques

There are two different techniques for captioning video; closed captioning and open captioning. Closed captioning is the technique of displaying the captioned text only when it is desired; this is the kind of captioning displayed by televisions. Open captions include the same text as closed captions, but the captions are a permanent part of the picture, and cannot typically be turned off. This type of captioning is seen when watching subtitling of a foreign language film. Open captions are not decoded by the television set, but are a part of the video information.
For video on the web, captions can be open, closed, or both. A common technique for open captioning is adding the caption text directly to the video itself. This requires a video editing or encoding program that allows you to overlay, or ‘burn’ titles onto the video. The captions are visible to anybody viewing the video clip and cannot be turned off. The more common way of captioning audio and video on the web is to use functionality within the multimedia players to display the captions along with or on top of the video or audio.

Portable media players cannot read or decode captions in the way that a television can, this meant that is was necessary to utilize the open captioning technique to provide text for the While loop vodcast.
Captioning the While loop Vodcast

One option which was examined was to use video-editing software, such as Adobe Premiere to ‘burn’ captions on to the video files. Although this method would allow control over the visual formatting of the captions, it was discounted for two main reasons:

This method would prove time consuming and would not allow for accurate synchronization.
Expensive, specialist software would be required as well as a skilled practitioner.

The current generation of portable media players cannot read a separate text-based caption file in the way that media players can with web based video, this meant that the use of SMIL (Synchronized Multimedia Integration Language) to caption the vodcast was not possible. This left Apple’s QuickTime Pro media player as the only viable option. QuickTime does use a Text Track file (known as a QTText document) to store the caption text and synchronization information as a separate track. It also stores audio and video tracks separately, however, when exporting the movie file from QuickTime to a file format other that the native .MOV file, the separate tracks are ‘flattened’ into a single video with the captions ‘burned’ onto the video.

The first step to adding captions is to create the caption text file. Media Access Generator (MAGpie), developed by the CPB/WGBH National Centre for Accessible Media (NCAM), is a free tool for creating and exporting caption files that can be utilized by media players, including QuickTime. MAGpie provides an environment which allows developers to view and listen to multimedia content, add captions, and synchronize the captions to the content by adding a timecode to each event. Although there are two versions of this software, Magpie 1.0 was used due to its ease of installation and use. Once the While loop vodcast had been successfully captioned using MAGpie, a text document was generated which can be read by QuickTime. This text document also contained basic formatting information, such as text size and justification.

The QTText file is opened with QuickTime and is displayed as text, the formatting of which can be adjusted in the QTText document. Using the functionality of QuickTime Pro, this text can be copied and pasted into the While loop video as a separate text track. The positioning of the captions and other parameters can be adjusted using the QuickTime software

Figure Five: Adding captions to the Vodcast

At this point, the caption text is still separate from the video and although it will be displayed when being viewed in QuickTime, it would not be displayed on a portable media device. To create the final, captioned, ‘While loop’ vodcast the file was exported as an .m4v file, which is compatible directly with the iPod and Creative Zen media players. The exporting process ‘flattens’ the video file which combines the caption text with the video meaning it is displayed on the devices.

The Creative Zen device includes software which will convert a video file so it is compatible with the media player and can be viewed on the device. It was therefore only necessary to generate one vodcast file using QuickTime as this was converted before being uploaded to the Zen device.

Initially the captions were presented as surtitles appearing at the top of the screen as there was already text at the bottom of the learning object. However, we subsequently swapped the position of the captions and the text to comply with accepted practice in captioning.

Preliminary Evaluations

The While loop learning vodcast was evaluated by eight students from the University of Teesside. All were males, aged between 18 and 45. Only two of them had some experience of using a media player before, and only one is currently studying Java programming. The students attended individually, and each was given a media player with the learning vodcast installed and a set of headphones and was instructed to take as much time as they needed to go through the vodcast. Two versions of the learning object were evaluated, one with audio and no captions, the other with captions and audio. They each used them for 10-15 minutes. Afterwards each student was interviewed using a set of questions to collect the data. For this part of the evaluation we have used the iPod media player. When testing the effectiveness of the captions, students were asked to watch the captioned learning object without audio, as well as with both the audio and caption text.

This introductory evaluation concentrated on the technical and design of the vodcast, but does not evaluate the pedagogical value of the vodcast as an aid to learning. This would require further investigation integrating the vodcast into the course content.

Student opinions of the learning vodcasts

All the students have agreed that they liked the concept of the learning object, specifically mentioning the element of multimedia. The students thought it was well constructed and well explained, although some of them have commented negatively on the tone of the voice over. All thought that the duration of the vodcast was appropriate, and that viewing on a small screen did not present a problem. One of the students found the lack of control over the learning vodcast frustrating, for example, they could only use the device controls to pause and rewind the content, rather than navigate effectively to specific elements within the learning object.

How students would use the learning vodcasts

The students provided a wide range of responses when asked how they would use the learning object. Three students indicated that they would only use them if they were part of a lecture or tutorial or required course content, while five stated they would use them for self-directed learning, for reference, investigating the concepts further, or would utilise them as part of revision. The way in which the vodcasts would be used seems very much to depend on the learning style of the individual students. One student commented that viewing the learning object on a portable media player would be useful to refer to when using a single PC monitor to work on.

Use of captions

The students had mixed responses to the use of captions. When viewing the captions without the audio, six of the eight students found it distracting as they had to focus their attention on two concurrent pieces of text. Conversely, two students commented they would find the caption text a useful aid to comprehension when supplemented with the audio. It should be stated that we have not as yet tested the captions with the main user group who would use them, students who are deaf or hard of hearing.

Further Work

One of the central issues that emerged from this project was the need to change the pedagogical structure of the learning objects to make them usable on portable media players. This was a result of the technology of portable media players which do not support the same level of interaction that can be experienced using Flash movies on Personal Digital Assistants (PDAs) with touch sensitive screens, or on a PC. Such adaptations may not be necessary when future generations of portable media players are released. Apple’s new iPhone, which will be released in the coming months, will feature a touch screen which may support interactive applications such as the While loop learning objects. This appropriateness of the learning objects for these devices would require further research.

Although preliminary evaluations have been carried out there is a need for in-depth evaluations which will examine whether the adaptations have compromised the pedagogical value of the original learning object. These evaluations will be carried out in conjunction with LTRI so the learning vodcasts can be used in their intended context.

Accessibility issues surrounding the use of captions have been explored. Captions were added to the learning vodcast with the intention of making it more accessible to deaf students. The presentation of the learning object requires the user to focus their attention on segments of code. Initial evaluations have suggested that the addition of captions is distracting to the user as the must focus on two concurrent pieces of text. Further evaluations will be carried out with deaf students in order to draw further conclusions on this issue.

During the evaluations the vodcast was presented to the students on the portable media player. Although the video files are available for download from a University server, we have not currently explored the use of Really Simple Syndication (RSS) which would allow students to subscribe and receive all vodcasts automatically. This would have related considerations in ensuring optimal file size was achieved during the development of the learning object to ensure the shortest possible download time.
Conclusion

Adaptations were made to the structure of the learning object including changes to the navigation, method of control, positioning of text and screen size. The interactive quiz could not be included as no suitable method of adaptation could be found in the timescale. The technical process required conversion of the Flash files to MPEG4 to be compatible with both the Apple iPod and the Creative Zen, and the addition of captions using MAGPIE. An audio track was also included. Preliminary evaluations reveal a mixed reaction to the vodcast. The students liked the concept of the learning object and only one was frustrated by the lack of control. The audio was generally felt to be useful but the caption version had a more mixed response, altough it has not yet been tested by a student with hearing impairment. The length of the learning object was regarded as appropriate, although the large file size (4.5 mb without captions and 17.5 mb with captions) and download time may be an issue if the vodcast were to be downloaded as an RSS feed. However, for the purpose of this exercise, we developed at optimal quality.

Further evaluations are planned with disabled students and with students studying Java programming to explore these issues in more depth. The results from this project will be valuable in terms of exploring the requirements for the creation of adaptable learning objects.

References

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