Define CAS and SDI services. Explain characteristics of CAS and SDI services.

CAS (Current Awareness Service): CAS is a service provided by libraries and information centers to keep users informed about new publications, research, or developments in specific areas of interest. It involves alerting users to new information as it becomes available, helping them stay up-to-date in their field of study or research.

Characteristics of CAS:

1. Customization: CAS is often tailored to the specific needs and interests of individual users, allowing them to receive alerts on topics relevant to their work or research.
2. Timeliness: CAS delivers information in a timely manner, alerting users to new publications or developments as soon as they become available.
3. Automation: CAS is often automated, using computer systems to monitor new publications or updates and send alerts to users accordingly.
4. Multiple Formats: CAS can deliver information in various formats, including email alerts, RSS feeds, or notifications through dedicated software or platforms.
5. Continuous Monitoring: CAS continuously monitors sources of information, such as databases, journals, or websites, to ensure that users receive the most up-to-date information.
6. Feedback Mechanism: CAS may include a feedback mechanism, allowing users to provide input on the relevance and usefulness of the information they receive, which can help improve the service over time.

SDI (Selective Dissemination of Information): SDI is a service provided by libraries and information centers to deliver relevant information to users based on their specified interests or criteria. It involves the automatic retrieval and delivery of information to users without the need for them to actively search for it.

Characteristics of SDI:

1. User Profiles: SDI is based on user profiles, which are created based on the user's interests, preferences, and information needs.
2. Automatic Retrieval: SDI automatically retrieves and delivers information to users based on their profile, without the need for them to initiate a search.
3. Customization: Like CAS, SDI is often customized to the specific needs and interests of individual users, ensuring that they receive information that is relevant to them.
4. Alerts and Notifications: SDI alerts users to new information that matches their profile, providing them with timely updates on topics of interest.
5. Efficiency: SDI saves users time and effort by delivering relevant information directly to them, eliminating the need for manual searching.
6. Feedback Mechanism: SDI may include a feedback mechanism, allowing users to provide input on the relevance and usefulness of the information they receive, which can help improve the service over time.

In summary, CAS and SDI are information services that help users stay informed about new developments in their field of interest. They are characterized by their customization, timeliness, automation, and ability to deliver relevant information directly to users based on their specified criteria or interests.