Comparative Analysis 
between Asynchronous and Synchronous Learning Technologies

Introduction

       	This brief paper will compare synchronous and asynchronous technologies in the context of online learning.  It will do so by focusing on Blackboard as an example of an asynchronous learning system and Elluminate Live! as an example of a synchronous learning system.  The paper will first consider the general characteristics of the systems, then examine their technological contexts and pedagogical implications (as types), as well as their respective strengths and weaknesses.

General Aspects of the Systems
The essential difference between synchronous technologies and asynchronous technologies is that synchronous technologies require everyone involved to participate at the same time, and asynchronous technologies allow everyone involved to participate at different times and from different places. 
Asynchronous learning technologies, such as Blackboard, tend to be widely integrated systems containing multiple tools.  Essentially, they are a collection of communication and information tools that have created new virtual spaces for teaching and learning.
Synchronous learning technologies, such as Elluminate Live! (EL!), tend to be discreet communication tools that use text, audio, or video to deliver communication in real time.  Other typical features include shared whiteboards and the ability for users to share computer interfaces. 

Technological View: Asynchronous
Educational institutions have several options in licensing Online Learning Platforms (OLPs) such as Blackboard.  Depending on features, data integration, number of students, and whether or not the program is hosted on a local server (or accessed via ASP), licenses can run from as little as $10,000-$12,000 a year to several hundred thousand dollars a year. 
If installed locally, these programs can run on a Windows NT server, Unix, or Linux.  With the server connected to the internet (usually via multiple T1 lines), they deliver database driven (most typically Oracle or Access) Web sites.  The programming that connects the database with Web page delivery is typically either Java or JavaScript. MySQL is sometimes used. 
OLPs require a technical support staff mostly for installation and occasional maintenance.  If the OLP is integrated with the institution's Student Information System (and other databases), significant programming expertise and database experts are required.  Typically, the system administrator for an OLP does not have to know programming or database management, but must be able to use a Web interface.
Users can access Blackboard and other OLPs via Windows or Apple Computers. Processor speeds and operating systems are seldom an issue.  The programs work with modem speeds as low as 28.8, but work better with broadband.  Most technical issues involve the individual user's browser (especially those that do not read or disable active scripts).  Recent versions of Internet Explorer and Netscape (with scripts and cookies enabled) almost always work best.

Technological View: Synchronous. 
Eluminate Live! is good example of Web-meeting software that provides opportunities for users to interact in real time using audio and video as well as shared whiteboard and text messaging.  EL! is available to in a variety of packages and is licensed to institutions based on number of seats (e.g. 3, 5, or 10) per session, costing from $ 200-300 to $700-800 a month. This is slightly more expensive than some of its competitors. 
EL! is Java based, so once the Java client software package (15MB) is installed on the user's machine, the user is able to connect with the central server (this is server-based IP broadcasting) and interact with other users.  Obviously, higher internet connection speeds are more crucial in such systems where voice and/or video over IP are conducted.  Modem users are not completely left out, but they will have more difficulty. 

Pedagogical View: Asynchronous Systems
The development of asynchronous learning networks has had an enormous impact on pedagogy.  Since the development of asynchronous technologies, there has been an explosion of new pedagogies appropriate for online learning  Simply put, it is the asynchronous learning systems that have not only revolutionized distance learning in the United States, but also revolutionized how teaching and learning occur in traditional US classrooms (see especially Bender, 2003; Duffy & Kirkley, 2004). .  Gillani (2003) demonstrates how the OLP has given teachers specific tools for developing learning activities appropriate to multiple learning styles.  Benbunan-Fich, Hiltz, and Harasim (2005) discuss how pedagogy for online environments has evolved from the old oral expository tradition (pedagogies of delivery) to more constructivist and collaborative models. 
Allen and Seaman (2003) report that it is a rare post-secondary educational institution in the US these days that does not offer an OLP,  whether or not the institution actually offers "distance learning" courses.  And even many US campus-based elementary and secondary schools are now using an OLP to (a) enhance peer-to-peer connections, (b) support collaborative learning, (c) distribute learning materials and activities, (d) allow more efficient and effective communication beyond the classroom walls, and (e) support collaborative performance based assessments such as ePortfolios and other student-centered learning activities 

Pedagogical View: Synchronous systems. 
Synchronous technologies such as Elluminate Live! essentially support faculty/trainer centered pedagogies of delivery in real time (the instructor speaking live to students).  Clearly, they also support interactive communication in real time.  Although EL! can be used as a stand-alone "classroom," it is most often used as a synchronous tool in an asynchronous learning environment (such as Blackboard).  In such cases, perhaps the most useful pedagogical tool is the testing feature.  The Academic version of EL! has a fairly robust quiz feature that allows instructors to quiz students in real time. 
It is significant that synchronous systems tend to support older (less student-centered) pedagogies, where the faculty member is the primary player in the class design and content is delivered by voice supported by video.  Further, assessments using such systems tend to support older (test-oriented rather than performance-based) approaches to student assessment.  Obviously, there are exceptions to this. 

Key Strengths and Limits of the Systems 
The key strength of asynchronous information and communication technology systems is that they widen access to learning and make learning available to anyone anywhere who has a computer and an internet connection.  The key limits are that they can only reach users with computers and internet connections. Additionally, asynchronous systems privilege users who already have adequate written skills and enough independence to "work alone in groups." 
The key strength of synchronous learning systems is that they provide opportunities for real time delivery, feedback, and assessment. Such systems can privilege those with better speaking skills than writing skills; users with high speed internet connections typically have the most success with the technologies. The key limit to synchronous systems is that everyone is required to participate at the same time. 

References

Allen, I., & Seaman, J.  (2003). Sizing the opportunity: The quality and extent of online education in the United States, 2002 and 2003. The Sloan Consortium. Retrieved    October 16, 2004 from http://www.sloan-c.org/resources/sizing_opportunity.pdf 
Benbunan-Fich, R.,  Hiltz, S.R., & Harasim, L. (2005). The online interaction learning model: An integrated theoretical framework for learning networks. In S.R. Hiltz & R. Goldman (Eds.),  Learning together online: Research on asynchronous learning networks. Mahwah, New Jersey: Lawrence Erlbaum Associates.
Bender, T. (2003).  Discussion-based online teaching to enhance student learning. Sterling, Virginia: Stylus Publishing.
Duffy, T.M., & Kirkley, J. R. (2004). Learning theory and pedagogy applied in distance learning: The case of Cardean University. In T.M. Duffy and J.R. Kirkley (Eds.), Learner-centered theory and practice in distance education. Mahwah, New Jersey: Lawrence Erlbaum Associates. 
Elluminate Live! (n.d.). Live elearning solution & collaboration solution software. Retrieved March 6, 2006 from http://www.elluminate.com
Gillani, B.B. (2003). Learning theories and the design of e-learning environments. Lanham, Maryland: University Press of America. 
Swan, K., & Shea, P. (2005). The development of virtual learning communities. In S.R. Hiltz & R. Goldman (Eds.), Learning together online: Research on asynchronous learning networks. Mahwah, New Jersey: Lawrence Erlbaum Associates.