Documentation Services: Current Awareness Service (CAS) and Selective Dissemination of Information (SDI)

1. Documentation: Meaning and Definition

Documentation is the systematic process of collecting, organising, processing, storing, and disseminating recorded knowledge for easy retrieval and use. It deals not only with books but also with reports, articles, patents, standards, research papers, digital files, and all recorded information. In modern usage, documentation also covers the preparation of bibliographies, indexes, abstracts, and databases that help users access information efficiently.
The concept of documentation emerged in the early 20th century when the growth of scientific and technical literature required new methods for handling vast amounts of information. Paul Otlet, the Belgian information pioneer, is often regarded as the “Father of Documentation” for his work in universal bibliography and information organisation.
Definitions

• Paul Otlet (1934): Documentation is “the process of collecting, classifying, and disseminating all kinds of documents.”
• UNESCO (1977): Documentation is “the activities involving the collection, analysis, organisation, and retrieval of recorded knowledge, particularly scientific and technical information.”
• Encyclopaedia of Library and Information Science (1997): Documentation is “the preparation, storage, and dissemination of documents and the provision of information through bibliographies, indexes, abstracts, and reference works.”
• S. R. Ranganathan: Documentation is a part of library science that deals specifically with managing scientific and technical documents, focusing on accessibility and utility.

Documentation is the science and practice of making recorded knowledge available for practical use. It includes preparing tools like indexes, bibliographies, abstracts, and databases, and it plays a vital role in supporting research, learning, and knowledge dissemination.

2. Documentation Services

The twentieth century witnessed a dramatic growth of literature in every field, especially in science and technology. This “information explosion” created serious challenges for researchers, teachers, and professionals who needed reliable ways to stay updated. Libraries and information centres responded by developing documentation services, which focus on organising, processing, and disseminating information so that users can access it quickly and effectively.
Documentation services are, therefore, specialised services provided by libraries or information centres to supply users with condensed, organised, and relevant information from the vast universe of documents. They go beyond merely storing books and journals; instead, they actively process knowledge into usable forms such as indexes, bibliographies, abstracts, digests, and alerting services.
Documentation services refer to the systematic activities performed by libraries and information centres to collect, analyse, organise, and disseminate documents or information in different formats. Their primary purpose is to keep users well-informed, updated, and equipped with the latest knowledge in their areas of interest.

Definitions of Documentation Services

• UNESCO (1977): Documentation services are “organised activities concerned with the collection, processing, storage, and dissemination of documents and information, particularly scientific and technical literature.”
• S. R. Ranganathan: Documentation services are specialised services that go beyond conventional reference work and deal with the interpretation and dissemination of scientific and technical documents for research and advanced study.
• International Encyclopedia of Information and Library Science (1997): Documentation services are “services that provide information in condensed and organized forms such as bibliographies, abstracts, indexes, and reviews to facilitate efficient information use.”

3. Characteristics of Documentation Services

Documentation services are distinct from general library services because they are specialised, user-centred, and dynamic in nature. They are designed to handle the enormous growth of scientific, technical, and scholarly information. Their characteristics can be described in detail as follows:

• User-Centred: The primary characteristic of documentation services is their orientation toward the specific needs of users, especially researchers, academicians, scientists, policymakers, and professionals. They are not general services but are customised to ensure users get the most relevant and timely information.
• Current and Up-to-Date: Documentation services emphasise current information. They are designed to alert users to the latest books, journals, reports, conference proceedings, and digital resources. Services like CAS and SDI ensure that users remain informed about new developments without delay.
• Continuous and Ongoing: Unlike one-time reference assistance, documentation services are continuous in nature. Information must be collected, processed, and disseminated regularly. For example, CAS bulletins or indexing journals are issued periodically (weekly, monthly, or quarterly).
• Selective and Filtered: Documentation services aim to reduce information overload by filtering, condensing, and presenting only the relevant information. SDI services, for instance, are highly selective because they deliver information based on a user’s subject profile.
• Value-Added Services: Documentation services go beyond merely providing documents. They add value by preparing abstracts, indexes, bibliographies, digests, and reviews that interpret or summarise content for quicker use. This makes information easier to understand and apply.
• Oriented Towards Scientific and Technical Literature: Historically, documentation services developed in response to the rapid growth of scientific and technical publications in the twentieth century. Even today, they remain crucial in fields like medicine, engineering, biotechnology, and applied sciences where new knowledge appears rapidly.
• Organised and Systematic: Documentation services require systematic processing of documents. Activities include classification, cataloguing, indexing, abstracting, and preparing bibliographies. The information is then disseminated in an organised manner, ensuring that retrieval is accurate and efficient.
• Based on Cooperation and Networking: Many documentation services rely on cooperation among libraries, research centres, and networks. Union catalogues, shared databases, and networks like INFLIBNET or DELNET make documentation services more comprehensive and practical.
• Time-Sensitive: The value of documentation services lies in their timeliness. Researchers and professionals need information quickly to support ongoing projects. Services like CAS and SDI are designed to deliver information as soon as it becomes available.
• Technology-Driven: Modern documentation services are highly dependent on information and communication technology (ICT). Online databases, digital repositories, search engines, and automated alerting systems are central tools for providing CAS, SDI, indexing, and abstracting.
• Cost-Effective and Resource-Saving: By providing filtered and relevant information, documentation services save both time and financial resources for users and institutions. Instead of subscribing to every journal, researchers receive only the most pertinent information through shared services.
• Educational and Supportive: Documentation services not only supply information but also educate users in staying updated, managing information, and using resources effectively. They support decision-making, policy formulation, teaching, and advanced research.

The characteristics of documentation services include being user-centred, current, continuous, selective, value-added, scientific in orientation, systematic, cooperative, time-sensitive, technology-driven, cost-effective, and educational. These features distinguish documentation services from traditional library services and make them indispensable in an era of information explosion.

4. Objectives of Documentation Services

Documentation services are designed to help users cope with the rapid growth of information by supplying them with organized, condensed, and relevant knowledge. Their objectives can be explained as follows:

• To Keep Users Updated with Current Information: One of the main objectives is to ensure that users remain aware of the latest research, publications, and developments in their field. Services like Current Awareness Service (CAS) provide regular updates about new books, journals, and articles.
• To Provide Selective and Relevant Information: Documentation services aim to reduce the problem of information overload by filtering and providing only the most relevant material to users. For example, Selective Dissemination of Information (SDI) delivers personalised updates based on user profiles.
• To Save Users’ Time and Effort: By organising and condensing information into abstracts, indexes, and bibliographies, documentation services save users valuable time. Instead of going through entire documents, researchers can rely on summaries or indexing tools to quickly identify useful material.
• To Support Research and Innovation: Documentation services provide researchers and scientists with timely and precise information that is essential for research, experimentation, and innovation. Updated knowledge helps in formulating new theories, solving problems, and avoiding duplication of work.
• To Maximise the Use of Information Resources: Many valuable resources in libraries and information centres remain underutilised. Documentation services highlight and disseminate this content, ensuring that users become aware of and benefit from resources such as specialised reports, conference proceedings, or government publications.
• To Facilitate Effective Decision-Making: Professionals, administrators, and policymakers often rely on accurate and timely information for decision-making. Documentation services help by supplying verified and organised data that supports informed choices in governance, industry, and academic planning.
• To Provide Condensed and Processed Information: Another important objective is to present information in a more manageable and digestible form. Abstracts, digests, reviews, and bibliographies reduce the bulk of literature and allow users to grasp the essence of documents quickly.
• To Encourage Resource Sharing and Networking: Documentation services often function through cooperative networks (such as INFLIBNET, DELNET, and WorldCat) to make information widely available. The objective here is to extend access beyond local holdings and promote sharing among libraries and institutions.
• To Bridge the Gap Between Documents and Users: Users may not always know how to locate or use complex sources of information. Documentation services act as a bridge, ensuring that information is not only stored but also reaches the right users at the right time.
• To Promote Lifelong Learning: By supplying continuous and updated information, documentation services encourage users to engage in lifelong learning. This objective aligns with the role of libraries as educational institutions that support both formal and informal education.

5. Workflow of Documentation Services

Step 1. Collection of Documents: The process begins with the systematic collection of relevant documents from different sources. These may include books, journals, conference proceedings, patents, reports, government publications, theses, standards, and electronic databases. Example: A library subscribing to Nature, IEEE Xplore, and national research reports.

Step 2. Registration and Accessioning: All collected documents are recorded and accessioned in the library or information centre. This ensures proper tracking, ownership, and systematic storage. Example: Each new book or journal issue receives an accession number and is entered into the system.

Step 3. Organisation and Processing: Documents are organised through classification, cataloguing, and indexing to make them retrievable. In documentation services, processing also includes abstracting, summarising, and preparing bibliographies to condense and interpret content. Example: Preparing subject indexes or summaries of articles in Indian Science Abstracts.

Step 4. Storage and Preservation: Processed information is stored in both physical and digital formats to ensure long-term preservation and easy retrieval. Libraries may use shelves, catalogues, OPACs, databases, or institutional repositories. Example: A university maintaining its theses collection in Shodhganga (INFLIBNET).

Step 5. Analysis and Filtering: Information is analysed to identify what is relevant and valuable for different categories of users. Filtering prevents information overload and ensures users only receive necessary content—for example, Librarians reviewing all new journal articles to select those applicable for a specific department.

Step 6. Preparation of Documentation Tools: Special tools are prepared to make access easier. These include:

• Indexes: Subject or keyword-based lists of articles.
• Abstracts: Concise summaries of documents.
• Bibliographies: Compiled lists of documents on a topic.
• Digests/Reviews: Condensed evaluations of current literature.
• Bulletins/Alerts: Notifications of new arrivals or publications.

Step 7. Dissemination of Information: The processed and filtered information is then disseminated to users. Dissemination may take two forms:

• Current Awareness Service (CAS): General updates for a broad group of users. Example (CAS): Circulating a monthly list of new journals.
• Selective Dissemination of Information (SDI): Personalised alerts based on user profiles. Example (SDI): Sending only the new articles on gene editing to a biotechnology researcher.

Step 8. Feedback from Users: Effective documentation services depend on user feedback. Libraries gather responses to refine profiles, improve tools, and ensure satisfaction. Example: A researcher requests fewer but more specialised alerts, leading to adjustments in the SDI service.

Step 9. Continuous Updating: Documentation is a constant process. With new knowledge appearing daily, libraries must keep updating collections, indexes, abstracts, and user profiles to remain relevant. Example: Weekly updates of research articles in PubMed or Scopus.

Documentation services follow a structured workflow beginning with collection, moving through organisation, processing, filtering, and preparation of tools, and finally ending with dissemination and user feedback. This cycle ensures that users always receive reliable, updated, and relevant information efficiently.

6. Current Awareness Service (CAS)

In the modern era of rapid information growth, users can't keep track of every new development in their subject areas. Libraries and information centres therefore provide a Current Awareness Service (CAS) to keep users informed of the latest publications, research findings, and information sources promptly. CAS is one of the most critical documentation services, especially for researchers, scientists, policy makers, and professionals.

Meaning of Current Awareness Service (CAS): Current Awareness Service is a documentation service that aims to alert users to new information as soon as it becomes available. It is broad in scope and not personalised to a single user. CAS works like a regular bulletin or update, ensuring users know new materials in their field of interest.

Definitions of CAS

• UNESCO (1977): “Current Awareness Service is a system of supplying information to readers about documents, reports or other sources of information immediately after they are received or published.”
• S. R. Ranganathan: CAS reflects the Fifth Law of Library Science (The library is a growing organism), emphasising the need to inform users about new knowledge continuously.
• Feather & Sturges (1997): CAS is “a service designed to keep users informed of the latest developments in their areas of interest, often through bulletins, newsletters, or lists of recent acquisitions.”

7. Objectives of Current Awareness Service (CAS)

The primary purpose of CAS is to keep users informed of the latest knowledge in their fields. Its objectives can be summarised as follows:

• To Keep Users Updated: CAS provides timely alerts about new books, journals, reports, and databases so that users stay aware of the latest developments.
• To Save Users’ Time: Instead of searching scattered sources, users receive consolidated updates that reduce effort and speed up access to information.
• To Maximise Use of New Resources: By highlighting newly acquired materials, CAS ensures that expensive and valuable resources are fully utilised.
• To Support Research and Teaching: CAS keeps researchers, teachers, and professionals informed, helping them prepare lectures, assignments, and research projects.
• To Reduce Information Overload: CAS filters the rapidly growing literature and presents only the most relevant and current information in an organised form.
• To Promote Decision-Making: By supplying current and authentic data, CAS assists administrators, policymakers, and professionals in making informed decisions.
• To Provide Equal Access to Information: CAS ensures that all users, whether students, faculty, or researchers, receive the same opportunity to access the most recent knowledge.
• To Strengthen the Role of the Library: CAS makes the library a proactive knowledge hub, shifting it from a passive storehouse to an active provider of current information.

The objectives of CAS are to keep users updated, save time, maximise resource use, support research and teaching, reduce information overload, aid decision-making, ensure equal access, and strengthen the library’s role as a dynamic information centre.

8. Importance of Current Awareness Service (CAS)

• Keeps Users Updated: CAS ensures that students, teachers, researchers, and professionals remain informed about the latest publications, research outputs, and developments in their fields.
• Saves Time and Effort: Users get consolidated updates that save valuable time instead of spending hours searching multiple sources.
• Promotes Maximum Use of Resources: CAS highlights new arrivals and subscriptions, ensuring that costly and valuable resources are effectively utilised.
• Supports Teaching and Research: Faculty members get current information for preparing lectures, while researchers gain access to the latest findings to strengthen their projects and dissertations.
• Prevents Information Overload: CAS filters and organises new information, presenting it in a manageable format such as bulletins, newsletters, or alerts.
• Aids in Decision-Making: Policymakers, administrators, and professionals benefit from timely and authentic information supplied by CAS for informed decisions.
• Encourages Continuous Learning: Regular updates enable users to develop the habit of keeping themselves informed, supporting lifelong learning.
• Enhances the Role of the Library: CAS transforms the library into an active information hub, showing that it is not just a storehouse but also a dynamic service centre for knowledge.

The importance of CAS lies in keeping users updated, saving time, maximising resource use, supporting teaching and research, preventing overload, aiding decision-making, promoting lifelong learning, and strengthening the library’s role.

9. Methods of Current Awareness Service (CAS) Delivery

• Bulletins and Newsletters: Libraries prepare printed or electronic bulletins and newsletters that summarise newly acquired books, journals, reports, and other materials.
• Lists of New Additions: Regular lists of newly added books, journals, databases, and reports are circulated to keep users aware of fresh arrivals.
• Contents Page Services: Photocopies or electronic copies of tables of contents of important journals are supplied to users, helping them identify relevant articles quickly.
• Display of New Arrivals: Recently acquired books, journals, and reports are physically displayed in a designated section of the library to attract user attention.
• Current Awareness Bulletins (Subject-Specific): Specialised bulletins are prepared for different departments or research groups, highlighting new materials relevant to their field.
• Email Alerts and Mailing Lists: Digital methods such as email notifications or mailing lists provide instant updates about new publications and resources.
• Web-Based CAS / Library Portals: Libraries use websites, intranets, OPACs, and institutional repositories to host CAS services, including updates on new acquisitions and research outputs.
• RSS Feeds and Social Media Alerts: Advanced CAS delivery uses RSS feeds and platforms like Twitter, Facebook, or WhatsApp groups to disseminate timely information.

CAS is delivered through bulletins, newsletters, new additions lists, contents page services, display of new arrivals, subject bulletins, email alerts, web portals, and even modern tools like RSS feeds and social media. These methods ensure that users receive current information promptly and effectively.

10. Selective Dissemination of Information (SDI)

Information production has grown exponentially in all fields—science, technology, humanities, and social sciences. Researchers, professionals, and policy‐makers cannot track every publication, report, or new document pertinent to their interests. Libraries and information centres address this by offering tailored notification services. SDI is a documentation service that delivers only the latest information items that match a user’s specific interest profile. It helps reduce irrelevant "noise", saves time, and ensures users do not miss essential developments in their domains.
SDI has roots in mid-20th-century information science. Hans Peter Luhn (IBM) first formulated the idea of routing new abstracts or documents to individuals who were likely to need them, based on predefined interest profiles. With advances in technology (databases, computer matching, email, RSS feeds), SDI has become more automated and precise.

Meaning
Selective Dissemination of Information means a service where the library or information centre supplies only those items of new information that correspond closely to the explicit interests or subject requirements of individual users or homogeneous groups. Users define or are profiled by topics, keywords, or descriptors. Then the system or librarian matches incoming documents with these profiles, and sends alerts, bibliographies, summaries or notices of new papers accordingly.
This contrasts with more general awareness services that provide broad updates without customising to individual interests. SDI is personal, targeted, and requires profiling of both user needs and documents.

Definitions According to Special & Research Libraries (INFLIBNET): “Selective Dissemination of Information (SDI) is a service meant to keep the user abreast with the latest developments in the field of his interest. It is a personalised service for an individual or group of users having identical information needs. It is a quick service that provides pinpointed and exhaustive information to the users.”

From ScienceDirect Social Sciences Topics: “SDI is defined as an organised method of distributing the latest information to users whose needs have been specified in advance”.

From Wikipedia (with caution since not always academic): “Selective dissemination of information refers to tools and resources used to keep a user informed of new resources on specified topics, including alerts, current awareness tools or trackers”.

From LIS Academy: “SDI is a process designed to provide researchers, professionals, and institutions with tailored information that aligns with their specific needs or interests.”

11. Objectives of Selective Dissemination of Information (SDI)

The purpose of SDI is to deliver precisely relevant, up-to-date information to users based on their individual interests so that they do not need to search widely. The objectives include:

• Provide Current Information in Predefined Areas of Interest: SDI aims to keep users informed about new literature, reports, articles, etc., in the specific fields they care about. SDI delivers information only for subjects already defined in the user’s profile.
• Deliver Relevant Information at the Right Time: Information must reach the user shortly after publication or availability. Timeliness ensures the information is helpful.
• Scan Broad Sources and Detect All Relevant Documents: SDI services should monitor multiple sources—journals, bulletins, reports, databases—from inside and outside the organisation to locate relevant items.
• Minimise Irrelevant Information: One objective is to filter out non-useful documents so users are not overwhelmed with irrelevant material. Only documents matching the user’s interest profile should be forwarded.
• Save Users’ Time and Effort: By doing the search, filtering, and alerting on behalf of the user, SDI frees them from continuous manual searching.
• Ensure Comprehensive Coverage of Relevant Developments: SDI should not miss essential publications available globally in the user’s field—even those from external or foreign sources—and deliver them if relevant.
• Notification of New Developments and Literature: Once a match between a user profile and document source is found, the user should be notified via citations, abstracts, or complete texts per service design.

12. Importance of Selective Dissemination of Information (SDI)

• Provides Highly Relevant Information: SDI delivers information that matches each user’s interest profile. It avoids broad updates and supplies only what is needed. This increases the relevance and utility of the information the user receives.
• Saves Time and Reduces Search Effort: Users do not need to scan large numbers of publications themselves. The filtering and matching done by librarians or systems cut out irrelevant material.
• Helps Manage Information Overload: With the explosion of published literature, SDI helps reduce the burden by sending only items that meet predefined criteria. This keeps users from being overwhelmed.
• Enhances Research Productivity: Researchers get alerts about new developments in their specialised areas. That leads to faster incorporation of new knowledge, avoids duplication, and supports more effective literature reviews.
• Supports Decision-Making: Professionals, policymakers, and educators benefit when they receive timely information directly relevant to their fields, enabling better, informed decisions.
• Improves User Satisfaction: When libraries deliver personalised information, users feel that the service addresses their needs. This increases trust and usage of library services.
• Maximises Use of Resources: SDI ensures that new materials—journals, reports, digital resources—are noticed and utilised rather than lying unused. Libraries get better ROI on subscriptions and acquisitions.
• Encourages Specialist or Expert Library Support: SDI often goes hand in hand with subject-specialist librarians or subject departments. That builds domain knowledge and expertise in libraries.
• Promotes Continuous Learning: Users remain updated with developments in their field, encouraging them to learn continuously. This is crucial in fast-moving disciplines.
• Fosters Inter-institutional Cooperation and Networking: Many SDI systems depend on shared databases, union catalogues, or external alert services. This encourages cooperation among libraries and improves access.

13. Methods of Selective Dissemination of Information (SDI) Delivery

• User Profile-Based Alerts: Libraries or information systems maintain detailed user profiles containing subject areas, keywords, authors of interest, formats preferred, etc. When new documents match those profiles, the system sends alerts (by email or notification). This ensures highly relevant documents reach the user.
• Email Notifications and Mailing Lists: Routine delivery of SDI content via emails or mailing lists. Users subscribe, indicating their interests, then receive regular digests or notifications of new material matching their criteria.
• RSS Feeds and Automated Feeds: Use RSS (Really Simple Syndication) feeds or similar automatic delivery tools that monitor data sources (journals, databases, repositories) and push new items matching the user’s keywords. This allows real-time or near-real-time updates.
• Online Catalogues / Discovery Systems with Saved Searches: Discovery platforms that allow users to save search queries; when new items match those saved queries, the system notifies the user. Useful for databases or catalogues that support alerts or RSS for specific searches.
• Bulletins / Newsletters Tailored to Subjects or Users: Creation of specialised SDI bulletin or newsletter for specific user groups (departments, research groups), summarising new articles, reports, etc. targeted only to their research interests. May include abstracts or titles of new items.
• Recommendation Systems / Intelligent Filtering: Use algorithms, AI/machine learning, recommender systems that analyse user behaviour, past preferences, and document metadata to suggest new resources. These systems reduce human mediation and improve relevance.
• Database Alerts: Many bibliographic, abstracting, and full-text databases allow users to set up alerts (e.g. on topics, authors) so that newly indexed content triggers notification. This is a core SDI method.
• Social Media / Mobile Notifications: Using mobile apps, SMS, or social media channels to send updates for users who prefer mobile or informal communication. This method integrates modern communication for timely delivery.

14. Comparative Table: Current Awareness Service (CAS) vs Selective Dissemination of Information (SDI)

• CAS = Ggeneral alerting service → Broad coverage, Less selective, Same for all.
• SDI = Personalised alerting service → Selective, Profile-based, continuous, Highly relevant.