ADL (Advanced Distributed Learning): Initiative by the U.S. Department of Defense to achieve interoperability across computer and Internet-based learning courseware through the development of a common technical framework, which contains content in the form of reusable learning objects .

ADSL (Asymmetric Digital Subscriber Line): A type of DSL that uses the majority of the bandwidth to transmit information to the user and a small part of the bandwidth to receive information from the user.

AICC ( Aviation Industry Computer-Based Training Committee) : An international association of technology-based training professionals that develops training guidelines for the aviation industry. AICC has and is developing standards for interoperability of computer-based and computer-managed training products across multiple industries.

Amplitude: The amount of variety in a signal. Commonly thought of as the height of a wave.

Analog: A signal that's received in the same form in which it is transmitted, although the amplitude and frequency may vary.

API (application program interface) : The set of tools used by a programmer to create a computer program.

Applet: A small application .

Application: Computer software; also called a program. There are many types of software that fit into the category of application. Application software is distinct from other forms of software, such as operating system and utility software .

ASCII (American Standard Code for Information Inter-exchange): A computer code in which characters such as letters and symbols are converted into numbers that the computer can understand.

ASP (Active Server Pages): A programming environment that combines elements of HTML and scripting. Web pages built with ASP can change dynamically based on user input.

ASP (application service provider): A third-party organization that supplies software applications and/or software-related services over the Internet. ASPs allow companies to save money, time, and resources by outsourcing some or all of their information technology needs.

Assessment: The process used to systematically evaluate a learner's skill or knowledge level.

Assessment item: A question or measurable activity used to determine whether the learner has mastered a learning objective.

Asset: 1) Intellectual property. 2) Hardware and software owned by an organization.

Asynchronous learning: Learning in which interaction between instructors and students occurs intermittently with a time delay. Examples are self-paced courses taken via the Internet or CD-ROM, &A mentoring, online discussion groups, and email.

ATM (asynchronous transfer mode): A network technology for high-speed transfer of data. Packets of information are relayed in fixed sizes, enabling smooth transmission. ATM supports real-time voice and video as well as data and can reach speeds of up to 10 Gbps.

Audio bridge: A device used in audio conferencing that connects multiple telephone lines.

Audio conferencing: Voice-only connection of more than two sites using standard telephone lines.

Audio graphics: Computer-based technology that enables simultaneous transmission of voice, data, and graphic images across local telephone lines for instructor-learner interaction.

Authoring tool: A software application or program used by trainers and instructional designers to create e-learning courseware. Types of authoring tools include instructionally focused authoring tools, Web authoring and programming tools, template-focused authoring tools, knowledge capture systems, and text and file creation tools.

Avatar: In online environments, a virtual digital image representing a person. In e-learning avatars usually represent the learners. The term comes from a Sanskrit word meaning an incarnation in human form.