1. Sensores analógicos moduladores
1.1. Resistivos
Various motivations are given in the documents mentioned above prior to the 1980s, for the development of national information policies. The policy guidelines presented by United Nations’ organisations and other national agencies (Gray, 1988: 92, 93), focused on the aim to provide access to national information sources. The emphasis in many of the initial national information policies was on the role of the national library of the country and the provision of access to the information produced nationally.
Later documents address wider international efforts which aim to ensure access to information sources. One such example is the UNISIST Programme, launched in 1972 by
UNESCO (UNESCO, 1979). The focus of this Programme was on scientific and technical information, and its aim was to develop scientific information policies and structures, and to assist developing countries in the development of scientific and technical information infrastructures (Gray, 1988: 93).
In 1974 the document: Information policy objectives: UNISIST proposals was published by UNESCO (1974). This document provides a checklist of information policy objectives and in it information is identified as a resource to be used for economic and social development. It also recommends the establishment of a governmental or government-chartered agency to guide, stimulate or co-ordinate the development of information resources and services from the perspective of national, regional and international co-operation. This document was followed by the NATIS (National Information System) Programme which was launched by UNESCO in 1974. This Programme was aimed at bibliographic documentation, libraries and archives. The Programme proposed a 12-point objective for national action set out for the standardisation of bibliographic documentation to be implemented by the national library and archives in countries. One of these points was the formulation of a national information policy. The two UNESCO programmes (UNISIST and NATIS) were not suitable for the conditions in the developing worlds and the NATIS Programme did not benefit Africa’s information environment (Rosenberg 1999: 13) as they provide guidelines and do not specifically address the issues experienced in many developing countries. These issues
include aspects such as a lack of information-related skills, for example illiteracy, poverty and a lack of or poor infrastructure development.
The UNISIST and NATIS Programmes were merged in 1976 and developed into the General Information Programme (GIP). The Intergovernmental Council for the General Information Programme prepared a new guideline on national information policy. The new guideline (GIP) expanded its scope to include not only scientific and technological information, but also other fields of information as well, mainly related to the relationship of information
technology to national information policy. The explanation given on the contents and scope of a later UNESCO (Wesley-Tanaskovic, 1985) publication, indicate that the guidelines given in these sources tend to be very general on how to develop national information policies which are strategically designed to:
... ensure that the emerging information society contributes to national development everywhere, removing the present global imbalances and inequities
(Wesley-Tanaskovic, 1985: 4).
A revised version of the original UNISIST proposals appears in the document, entitled
Guidelines on National Information Policy: Scope, formulation and implementation, prepared by Wesley-Tanaskovic for the General Information Programme and UNISIST (1985). The document was only designed “... to provide the general concept for formulating and co-ordination of the national information policies from which the users are free to draw those ideas which they feel best suit their national situation”. The idea that member countries of UNESCO should set up national committees is encouraged in this document. The UNESCO / PGI-UNISIST document calls for UNESCO membership countries to co-operate with
governments and various communities including information-related specialists in (UNESCO) membership countries. This document presents a step-by-step approach to national information policy formulation and implementation. The steps listed in the Guidelines on National Information Policy: Scope, Formulation and Implementation, describe the policy process as follows:
(i) Determine the overall framework for the project;
(ii) Define the scope of the needed national information;
(iii) Formulate a national information policy;
(iv) Implement the information policy;
(v) Establish a national information co-ordinating organisation.
The document also lists the scope of the policy in a fairly general manner:
• The need to address the generation of information (e.g. publishing industry;
• legislation, such as patent laws and copyright);
• Address the collection of information (e.g. acquisition of foreign publications);
• Establish a system for the distribution of information (e.g. national bibliographies, abstracting and indexing services, computerised information networks, document delivery systems);
• Compile an organisational framework and the provision of resources (e.g.
manpower, physical facilities and funding) (Wesley-Tanaskovic, 1985: 9).
The issues discussed above as listed in the UNESCO / PGI-UNISIST document (Wesley-Tanaskovic, 1985) are all relevant to the development of a national information policy, but can only serve to provide the general concepts and guidelines for national information policy development and implementation. The national situation of each country would need to be established by carrying out a situational analysis before developing a national information policy. Another UNESCO document, entitled, Implications of modern information technology for national information policy and planning (1997), continues the trend to expand the
national scope of policy and stresses the importance of co-ordinating national systems of information.
Another document was prepared, namely UNESCO’s Major Programme VII “Information systems and access to knowledge” (1985). This document encourages member countries to increase their national capabilities for providing and exploiting information for development.
All the above-mentioned documents provide general guidelines and recommendations for the development of a national information policy and stress the value of information for a
country’s development.