Conclusion

While this model seems to address many of the issues that have been raised, and offers some hope of being massaged into a solid classifactory and predictive model, it is not without its weaknesses. There are several criticisms that might be made about the model, including:

1. The structural layer seems to be somewhat heavy and the application layer somewhat light. For example, ANS.1 and SGML are very different levels of structuring. Similarly, a case might be made for movinng CALS and STEP to the structural level, leaving little to be placed at the application level. One might suggest that structure become "generic structural" and application become "domain structural."
2. The model does little as currently configured to address the division or management of standards in what must be defined as two of the most important application areas: structured records (data bases) and documents. Indeed there is no clear column for structured records.
3. There is no precedent for the linkage of operation standards to data representation standards in this way. In some ways, the appendage of tightly coupled operations begins to expand this reference model to a vast amount of the standardization landscape.
4. At a theoretic level, there is assumed to be a reasonable progression from signal to data to information and knowledge. The signal/data transformation makes good sense in thinking about the low levels of data interchnage standards. Many people have suggested that organized data is information and information with methodology is knowledge. This suggests a more semantically attractive axis than the atomic, elemental, structural division, but has the problem of collapsing all operational standards into the highest level, which itself creates problems.