Other issues in the data conversion process

Due consideration must be accorded to the data conversion process as data form the heart of the LIS and that any strategy should consider both their immediate and long term use. The Tomlinson Associates study (1993b, p.44) proposed that the following questions associated with digital data conversion and translations be considered for each data set application and agency:

Does the schedule fo r investment in data conversion lead to the production o f information products with the highest benefits?

• Has the design o f the data base ensured that all the necessary data components will be available? This includes both attribute and topologic information

• Will the data custodian be able to protect sensitive data?

• Are digital data conversion requirements accommodated within the source data set? • Is the appropriate meta-data being conveyed? Important details include map

projection, scale and currency information.

However, there is also a need to ensure that the data attains a standard acceptable to all the data users and providers involved in their collection, use, dissemination, etc. “Data standard” is used here to mean some or all of the following data aspects. As stated earlier, some data aspects will be necessary while others may be desirable in a data sharing environment; these are categorised accordingly although this will differ to suit the needs of the organisation:

Necessary

• Common geo-referencing. All spatial data should be positioned in a common coordinate referencing system, preferably at the parcel level for a LIS.

• Complete. The information product must provide all necessary data required for the targeted decision-making process with minimal reference to other sources, i.e. minimal ambiguity.

• Accurate and relevant. This is necessary to avoid possible erroneous interpretations of the data and prevent further verification and checking procedures.

• Up to date and timely. Information value deteriorates with usage and time. Thus, data must continuously be maintained and changes incorporated into the database records, preferably with the shortest time delay, and under the responsibility of the data custodian.

Desirable

• Official. The LIS informational product and services output needs to be accepted as an official document to increase its usability, and hence its value. In short, it should inspire the users’ confidence and reliability of the data.

• Security. There must be a form of control over the information from being altered, disclosed, destroyed and abused by unauthorised users. One method to avoid this is the use of appropriate copyright laws. These however must recognise that in an integrated environment, parts of the data may belong to different providers and the

limits of modification allowed on the data sets must be indicated. There is also a need to develop security and data back-up measures of the digitised data sets.

• Data Standards. Data standards should be developed to ensure uniformity within and across data sets produced by the various suppliers. Depending on the level of inter­ agency co-operation, a common framework of spatial data representation may need to be developed and implemented, e.g. common naming conventions, standard protocol, data dictionaries, etc.

• Cost effective. Essentially information that is collected, maintained and shared should not cost more than its perceived value. Otherwise, alternative arrangements must be sought.

However, the data aspects above are indicative and do not necessarily apply to all LIS data investment scenarios. For example, where confidential data are concerned, security may be a necessity rather than desirable. Any check measures should however consider the key points above although determining e.g. what ideals are necessary, how these should be incorporated, who are responsible, etc. depends on the individual implementing agency.

4.4.4 Cost and Data Sharing Issues

The sharing of digital spatial data costs should be the eventual ideal of any LIS implementation program within government departments and agencies. The issue gains added weight in developing countries because of the benefits and advantages in reducing duplicative costs and efforts in data collection. Calkins (1992, p. 283) states two reasons for sharing spatial data, i.e. those related to cost, and the possibihty of access to a wider range of spatial data. Sharing of data, according to Calkins (1992), provides access to additional data at marginal cost via the reduction of e.g. accessing or travelling costs. Although no digital data sharing scheme was encountered in this case study, the strategic cost implications and practical significance of data sharing merits discussion. The definition of spatial data sharing in this context adopts the definition by Calkins (1992, p.284), which is the: “... electronic transfer of spatial data between two or more organisational units where there is independence between the holders of the data and the prospective user”.

In developing countries where there are generally scarce resources, principal agencies involved in the management of land information can save costs by adopting cost sharing measures. Although there may be some data related hurdles that needs to be overcome e.g. relating to data access, data documentation or meta data, hability, inter-organisational agreements, legal authority and individual data sets tending to be too specific in terms of coverage, format, scale and applications, the eventual advantages of cost sharing and minimising effort duplication appear to outweigh these initial difficulties. Huxhold and Levinsohn (1995) opined that all geographic data contain elements that are common to the varying users and proposed that these should be identified and used as a basis on which to integrate the other varying data sets. Holstein (1992) for example states that cost sharing allows real demand and priorities to be established and proposed two circumstances for the sharing of costs for land information products:

• Where costs are shared between the land information management agency and the user, e.g. in larger municipalities and infrastructure agencies which can contribute in part or whole, to the cost of supplying land information.

• Where a group of user agencies share the total cost of specific products, i.e. when a group of users request a provider (public or private) to undertake a land information task, e.g. aerial photogrammetry or base mapping. The main cost determinants include the users needs, up-date frequency, accuracy and amount of data.

The Mapping Science Committee (MSG, 1993) of the United States quote two examples of successful data sharing and co-operation programs of spatial data. One case involved the National Geodetic Survey (NOS) where the data donors, i.e. the private, county, state and other federal organisations, provided vertical and horizontal control points for inclusion in the National Geodetic Reference System (NGRS). Since 1980, the NGS has received 65,000 horizontal control points and 36,000 km of geodetic levelling from other organisations, with cost savings estimated at about $79.4 million (65,000 points X $1000 per horizontal point = $65,000,000 and 36,000 km X $400/km of vertical data = $14,400,000). Future plans are afoot for the inclusion of gravity data and for improving geoid height modelling which are essential for accurate GPS-derived orthometric heights. The second case involved the North Carolina land records management program, which

resulted in legislation that “provided for financial and technical assistance to local governments in the areas of base maps, cadastral maps, a uniform system of parcel identifiers, and automation of land records”.

Some interesting points arose from their process of developing standards for the base and cadastral mapping that lead to a uniform parcel identifier. For example, the collaboration and development of orthophoto maps resulted in identifying unsurveyed areas and conflicts in property boundaries. The resultant surveys were used to update the cadastral maps and data files. Also, co-operation between the federal, state and counties evolved and as the North Carolina state moved into digital mapping, “duplication of effort in the soils mapping area was eliminated and sharing of soils files was effected”.

Cost sharing and data sharing can therefore be considered as linked issues. One of the main principles in cost sharing is for the end users of these information products or services to reimburse part or all of the data collection and transaction costs of the provider. Data sharing meanwhile is primarily driven by the need to minimise costs in the collection and maintenance of land related data. This may be initiated resulting from the realisation that much of the information required by the varying users is common and that data sharing can eliminate the redundancy in data collection and its maintenance.

One of the essential requirements for any data sharing arrangements however is the availability of standards and data quality control mechanisms on the spatial data. Otherwise, data that are provided, exchanged or used by the users and providers may not be in a suitable format for integration. The US MSC (1993, p. 102) noted that, “The benefit of the standardization of data to all government agencies - federal, state, and local - and to the private sector is such that this incremental cost will be recovered to the federal treasury over time as direct savings in government programs and in increased efficiency in the private sector.” A further aspect is the knowledge or information about the land related data’s existence, contents and fitness for an application, i.e. metadata. As stated by the MSC (1993, p.97), “Metadata support data sharing by providing information on many aspects of spatial data, each aspect having meaning in particular application contexts. Metadata that describe data base contents include data dictionaries and definition, attribute ranges, and data types. The origin and ancestry data is critical for ascertaining the validity and suitability of data”.

Data sharing and the incentive to donate information however may need to be driven by “a public sense of responsibility and a recognition that in many instances the beneficiaries of the program will be the data donors themselves” (MSC, 1993, p. 102). The research attachment in Sabah noted that this was a significant issue at the interdepartmental level because some data owners preferred to retain sole custodianship of their data; this indicated their lack of appreciation on the costs of non-integration and co-operation, and the tendency to view information as a source of authority.

The MSC’s (1993, p.94) report on the co-ordinated spatial data infrastructure for the United States proposed the model in Figure 4.7 for a spatial data sharing program. The main policy areas include data standards policy, depository policy, distribution policy, and cost sharing policy.

FIGURE 4.7: Components of a Spatial Data Sharing Program. (Adapted from MSC, 1993, p.95)

State Spatial Data Advisors

Metadata Servers

Spatial Data Servers

FGDC^ Certified Quality Assurance Programs

Users o f Spatial Data

Producers and Co-Producers of Base Data

Federal, State, Municipal, Private

Arrangements for Base Data Development

Plans for Base Data Development

Cost Sharing Agreements

If full cost recovery cannot be implemented due to legislation or other constraints, then alternatives such as cost sharing consortia may aid in reducing the LIS investment burden. They could include arrangements between the data users, owners and custodians at the various administrative levels. Some of the legal issues in cost recovery have been reviewed by Salmon (1989) and include:

• existence of legal authority to permit such undertakings, e.g. constitutional or statutory grants

• provisions on what constitutes a public record • whether any agency records can be exempted

• what provisions have to be made for copying records and how much agencies can charge

• issue of system control and its products

• whether system managers will always be able to meet stated deadlines for providing required copies

• liability, e.g. issues of reasonable care and quality in information products and services, disclaimers, and security.