One of the most important functions with many products for address management comprises optimized methods and algorithms for error tolerance. Why? In every visual or acoustic transfer or entry of address data, reading, hearing or spelling errors occur very easily. The information given is entered in a different chronological order or simply abbreviated differently.

Here are some examples of what this can lead to:

These deviations are not the exception but almost the rule. Studies have shown, that 10 - 30 percent of the addresses are changed every time in some way when they are transferred visually or acoustically several times or recorded several times.

Human intelligence can grasp the significance of the respective concepts due to prior knowledge. This ability, paired with the ability to associate, usually makes it easy for human beings to recognize two different addresses which were "changed" because of transmission errors and to judge whether they refer to the same person or company or not.

For a computer this problem is much more difficult to solve without uniform customer and prospect numbers. Nevertheless, there are several methods, which lead to very good results:

With an error-tolerant string comparison alone a useable address management solution is still not possible. For optimized address analysis, an additional building block is required with lexical, syntactic and semantic comparison. The software - just as in a human reaction - must be able to decide what meaning the terms that are being compared have. That is the only way the software can make "meaningful" decisions. Some examples for this:

Despite the close match there is only small probability that this is the same person:

Correct character interpretation is of crucial importance as part of initiatives for securing the quality of customer and address data during the transmission, acquisition and storage of address information, especially in an era of globalisation and internationalization. The Uniserv products, e.g. for postal validation and duplicate checking, are Unicode-capable, in order to reliably preclude problems with various character sets and their display from the very beginning. Against this background, the UNISERV products therefore also support languages such as Latin, Arabic, Greek, Cyrillic, Hebrew, Katakana, Hiragana, Hangul, etc.

Unicode itself is an international standard, in which a digital code is specified in the long-term for each meaningful character and text element of all known literate cultures and character systems. The aim is to eliminate the problem of different incompatible encodings in different countries. Conventional computer character systems consist of a character set of either 128 (7 bit) characters, such as the very well-known ASCII standard, or 256 (8 bit) characters, such as ISO Latin-1. After deduction of the control characters, 96 elements can be displayed as characters and special characters in ASCII and 192-224 elements in the 8 bit ISO character sets. These character encodings permit the simultaneous display of only a few languages in the same text, unless different fonts with different character sets are used in a text. This hinders international data exchange to a considerable extent. On the other hand, Unicode provides each character with its own code, independent of the system, program and language. As a result, all known characters are supported as standard in the Unicode system. The Unicode Consortium is responsible for the standard (www.unicode.org).