When most of the variables of the phenomenon under study are well known, and especially when our descriptions have a discreet character, it is very recommendable the use of codified systems for the systematization of the information.
The codification guarantees a uniform observation of the essential parameters of the phenomenon, even when in the process intervene more than one researcher. It also presents the advantage of reducing the subjective factor of the obtained information (Valls, 1990).
The codified information (Kashdan, 1982) is easy to understand, to process, to regroup and study, all of which influences positively in the final quality of the observation and in the rapidity of its interpretation. The codified systems are not difficult to prepare. First we establish the basic parameters that we want to observe or measure at each point, and all possible variables of its results. Don't forget to include always a field under the name "and other" to save any forgetfulness or unexpected result.
Next we order the selected parameters in a logical way and we represent them in card of 3 for 5", for example. The centre of each card and its back will remain free for "irregular" descriptions (those that are extremely variable or when we don't know all their possible behaviors). We will use the edges of the card to codify the information. As an illustration, Figure 1shows a card created by the author for the codification of the lithogeochemical sampling (Valls, 1990).
Figure 1. A codified card for lithogeochemical sampling.
Each card is an independent and complete unit of information, where we can reflect all the useful information, from the date and hour of the observation until the results of the measurements and analysis accomplished. The combination of these cards will form the database of our investigation than can be easily exported to any computerized data system.