Data Capture
Data capture is a term usually described to methods of gathering data automatically as part of a transaction. This means that the data must be stored in machine-readable form. Data capture methods remove the need for data to be input from a keyboard and they therefore eliminate the most likely source of error - the human operator. Also, since there is no need to enter the data from the keyboard, data capture methods produce faster and cheaper input of data. Data capture can be divided into two broad methods.
Document reading methods:
The data is present on the source document in computer readable format. The data may be pre-printed (bar code) or added to the document before input (value of a cheque). The document is input to the computer and the data read from it.
Sensing methods:
Special sensors are used to obtain the data which is transmitted to the computer. Examples include traffic light systems and automatic weather stations.
Choice of Method
The following factors will influence the method of data capture chosen for a particular application.
| Cost | Both the cost of the initial hardware and the running costs in terms of printing, staffing etc. |
| Volume | Volume of data to be captured. The larger the volume of data to be captured the more need there will be for specialised data capture. |
| Speed | The speed with which the data needs to be captured and also the speed that data must be input to the computer. |
| Accuracy | In some applications 100% accuracy must be aimed for, in others this is not so important - e.g. counting cars passing along a busy road in one day. Accuracy to nearest 100 might be acceptable. |
| Environment | The working environment may affect what data capture methods are available. Magnetic based systems would not be possible in an aluminium smelter where there are strong magnetic fields. |
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