Electoral computer systems such as voter registers, electronic voting systems, election results systems and personnel management systems are developed and implemented to store and make use of data. Ensuring the reliability of this data is crucially important for any electoral process.
There are several measures that can be taken to ensure the reliability of data used in electoral computer systems.
Use reliable data sources
Methods to collect and capture data need to ensure that the data is reliable and that is not altered in the process. Voter information, for instance, is more accurate if obtained directly from the voters themselves and not from indirect sources such as other organisations' databases, which may be of questionable quality. The most accurate election results data is obtained directly from the polling places or counting centres, instead of media reports, election observers or political parties.
Data capture methods
The next step to consider is the method by which data is captured from the source. Data can be captured in a variety of ways: on a paper form (which could be handwritten, marked with computer readable marks or typed), by telephone (after which the data is usually written down or typed into a computer by an operator), by face to face inquiry (when the data may again be written down or typed into a computer by a staff member), by users directly entering data into electronic forms connected to the organization data centre, by an electronic voting device, and so on.
Some forms of data capture are more reliable than others. Handwritten forms are probably most prone to error, as handwriting can often be hard to read or decipher. To minimise the difficulty in reading handwriting, persons completing forms can be encouraged to write clearly in capital letters in blue or black ink. Clear writing can also be encouraged by printing forms with guide lines that are designed to make users write each letter or number in a separate box on the form. If it is possible to pre-print any known data about information needed in the form, this may help reduce the amount of handwriting needed and therefore the error rate.
Where data is received verbally by an operator or staff member, appropriate training and procedures can ensure that the operator faithfully captures the correct information. For example, information can be read back to the client to check that it is correct, and the spelling of words checked if appropriate.
Forms that include optical mark recognition devices such as bar codes can be used to simplify data entry and raise accuracy levels. Bar codes can be used to identify the type of form used, where the form was obtained, what the unique number of the form is, and so on.
Data captured electronically, where the data is typed by a user directly into a computer supplied form can be more reliable than data captured from handwritten forms or data taken verbally, as users can be expected to know exactly how their data should appear. However, such data is only as reliable as the user is accurate.
Training of data entry staff
Staff needs to be trained in techniques designed to optimise accurate input and to ensure a safe working environment. For example, regular breaks prevent eye strain and fatigue. Furniture and computer equipment can be situated to ensure good posture and sound ergonomic practices. Distractions such as staff conversation and discussions while entering data can be minimised to ensure input accuracy.
Data verification
One of the best ways to ensure the accuracy of data is to apply data verification techniques. The most common data verification technique (where data is being typed into a computer from a paper record) is to enter every piece of data twice, using two different operators for each piece of data. The results of the two data entries are compared by computer. Any variation is highlighted, and a supervisor is required to make any appropriate correction. This technique usually gives very high accuracy rates.
Double-keying of data can also be used to identify data-entry operators who are not achieving a high level of accuracy. Where under-performing operators are identified, this may indicate that more training is needed or that the operator is not suited to that kind of work.
Data can also be verified by entering the data once, and requiring another officer, perhaps a supervisor, to recheck the data on the computer screen or on print-outs, to confirm that it is correct, or make any necessary corrections.
Using either of the above techniques, it is desirable that data is entered once by one person and then either re-entered or rechecked by a different person, since people can make systematic errors and therefore repeat the same mistakes every time. However, it is less likely that two different people will make the same systematic errors, so a second person is more likely to pick up the mistakes made by someone else.
It is also possible that form design can lead to users or data-entry operators making systematic errors. If significant numbers of similar errors are discovered regularly when a form's data is being recorded, it may be that the design of the form is at fault. Redesigning the form may help to lower error rates in this case.
Some data can also be verified by checks built into the data capture programs. For example, when entering voting places into a database the data entry program may verify the voting place address against a computer table with all valid addresses and accept only those voting places with valid addresses. Such a verification technique does not necessarily ensure that the correct address for the voting place has been entered, but it does ensure that all the recorded addresses are indeed real.
Similarly, arithmetic checks and logic tests can be built into data-entry systems involving entry of numbers so that the data entry operator is prompted to correct the data, the entry is cancelled, an error log is written or any another relevant action is taken. For example, if an operator is entering a polling place voting data, the system can be programmed to query any result that shows more votes counted at the polling place than there are voters registered to vote at that place. Trends can be also calculated by computer systems and any results that vary from the trend by an unusual amount can be identified and queried.
Ensuring reliability of data after it has been captured
Once data has been entered into a computer system, it is important that it be stored securely and maintained, as well as used in a manner in which its integrity is not compromised.
Ensuring availability of data
Once data has been captured and stored securely in a computer system, it must be made available to users in a way that does not allow undue access to the data or the possibility of data corruption.
There are two main components to ensuring availability of data and thereby minimising the risk in entrusting valuable data to technology. These are ensuring that systems operate to deliver data as needed, and backing up data to guard against system failure or data loss.
Making data available
Making data available to users is one of the main purposes of a computer system. At the same time, however, ensuring the integrity of data is of key importance. When dealing with sensitive data, access should be restricted only to those users that need it by using passwords, login permissions or other available controlling mechanisms.
When data can be shared more widely, a difference may have to be made between users that need to access data for information and those that need access to change or update the data. Similar mechanisms, such as password and login permissions can be used to limit those users who are able to change data to those who have a need to do so. In addition, where users are permitted to change data, verification techniques can be used to minimise the chance of errors occurring.
Data backup
The final safeguard against system failure and loss of data is data backup. Regular back up can mean taking these precautions at least once each working day, more often if crucial data is being collected, such as during an electoral event. Data can be backed up on a wide variety of formats and media such as removable disks of various kinds, multiple hard disks, DVDs, and magnetic tapes, to mention a few.
The organisation's overall information technology strategy can document a formal backup regime. Ideally, data backup can be automated to ensure that human error does not cause problems. However, regular checks of automated backups will still be necessary to ensure that computer error does not also cause problems.
“Live” data can be backed up as it is created, by use of mirrored hard disks, which could be located on the same server or on separate servers. Using mirrored disks, the same data is simultaneously stored on two or more disks. This means that if one disk fails, data can be restored from the other. It is preferable to use separate servers for mirrored disks, as a second server can be used if the first server fails completely.
Software programs, both commercial programs and those developed in-house can also be backed-up so that they are available to reload if the production versions of the programs are lost or corrupted. Most programs come loaded on disks. Increasingly, however, programs can be downloaded from the Internet. In this case, backup copies should be stored locally, as there is no guarantee that the same programs will be available on-line in the future. Program disks that are stored in a data library and managed by a responsible officer or staff unit can then be easily located and used if necessary.
Care should be taken, when backing up program data, that software licences are not breached. Most licences include permission to keep backup copies of software.