Countries contemplating the use of geographical information systems

 (GIS) for redistricting need to give careful consideration to the advantages and disadvantages of introducing a GIS. The reasons for adopting such a system need to be examined, and clear objectives identified.

Issues to be addressed include:

• expected benefits of introducing GIS

• improvement of the efficiency or effectiveness of the redistricting process

• availability of relevant maps

• costs of introducing a GIS for redistricting

• costs of obtaining additional maps

Potential GIS users may find it useful to conduct a thorough cost-benefit analysis to determine whether the expected benefits of adopting GIS for redistricting justify the anticipated costs of implementing and maintaining this technology.

Costs and benefits of using GIS for redistricting

Some of the direct costs that may be associated with the use of GIS for redistricting include:

• acquisition of computer hardware and software

• acquisition of customised software

• hardware and software maintenance and support

• data maintenance, including creating, editing and deleting data

• hiring of qualified personnel

• training staff

Some of the benefits that may be associated with the use of GIS for redistricting include:

• time saving for routine and repetitive tasks

• faster provision of information

• wider range of information provided

• more accurate information

• new range of output—maps, reports, etc.

• improved quality of redistricting decisions

Some costs and benefits—such as the cost associated with purchasing the GIS system and the time savings benefit—are relatively easy to identify and quantify. Other costs and benefits, however, especially indirect ones, are not as easy to identify and quantify but have to be taken in account when doing a cost-benefit analysis.

The cost of employing GIS for redistricting will vary dramatically depending on the availability of electronic data and the effort required to encode the data if it is not available electronically. If digitised maps of the entire country or of the region under consideration are available, the costs associated with adopting GIS can be expected to be more affordable. On the other hand, if a digital map data base has to be created, and the cost of this cannot be shared with other government agencies or organisations, the effort and cost required may not be worth the anticipated benefits of using GIS for redistricting purposes.

Choosing a GIS software package

Once the decision is made that expected benefits outweigh costs, the next step is to choose a GIS hardware and software.

Various options need to be analysed to determine which one will best meet the identified objectives. This includes deciding whether to develop the software in-house, to purchase a standard GIS commercial package, or to purchase a standard GIS software package and customise it (using in-house staff or consultants). Acquiring a standard, proprietary GIS system is likely to be cheaper, easy to use and well-supported by the provider, but may lack some of the required functionality identified for the specific redistricting exercise.

Some questions to consider when selecting a GIS software package include:

• hardware specifications required to run the software (processor speed and memory, disk storage capacity, storage capacity)

• operating system needed to run the software

• software ease of use

• documentation availability, quality and languages

• training availability

• software vendor market position (assurance of on going development and support)

• availability and cost of software upgrades

• software functions

• ability of software functionality to meet requirements

• extent of software package customisation to meet requirements

• software costs

In addition to researching these questions, a decision-making process may include benchmark tests and/or pilot projects with select GIS packages. For example, a benchmark test might be organised in which three or four GIS vendors are provided with a list of tasks that the potential buyer would like the GIS to be able to perform. The potential buyer might also supply data for use in the exercise. The vendors would then attempt to demonstrate that their system meets the potential buyer's requirements. This exercise requires a fair level of expertise and awareness on the part of the potential buyer, especially regarding the identification of the tasks to be performed by the vendors, but it may be well worth the effort.

Implementing GIS for redistricting

Once a GIS has been selected, it must be implemented. Even if there is nothing technically wrong with the GIS system chosen, problems may arise with its use depending on the how the system is implemented. Factors that could be important to the success or failure of the GIS implementation include:

• commitment to the use of information technology and digital data

• availability of experienced staff and/or consultants

• adequate training to enable staff to operate and support the system, including data entry, creation and maintenance of the GIS databases

• allocation of enough time and resources to create the databases and test the system extensively before being adopted

In addition to choosing the GIS package, ordering the necessary equipment and installing, implementing and testing it, the adoption of GIS technology for redistricting involves a complex interplay of technical and socio-political factors. Therefore, it is important to plan the implementation process carefully in order to ensure that the resources needed for the successful transition from the current to the new redistricting system are in place, that redistricting deadlines are met and that the redistricting plans produced are as accurate as possible.

This effort not withstanding, the risk remains that the optimal redistricting plan may not be created or selected.