cluster names which serve to break up larger, less familiar fields like science which experienced very rapid proliferation in recent history.
Repeating what was said above about categories, levels and boundaries. Approach these notions flexibly. Boundaries between various groups and between various levels are not completely impermeable. The fifty-six (56) Skill Clusters should be thought of as loosely-coupled and partially overlapping. Intra-segment coupling and overlap is greater than inter-segment coupling and overlap.
We have tried to maintain the distinction between the skill and the object to which the skill may be applied. In contrast with other skills vocabularies, the Skills Directory tends to focus on actual skills and to avoid cataloging objects, conditions and situations which may demand that the skill or ability be exercised. For example, many ENGINEERING skills are included, but the products of these skills generally are excluded (i.e. sensors, motors, actuators, integrated circuits, rotary machinery, propulsion systems, etc). The Directory includes many talents under MEDICINE but excludes the diseases and disorders to which they are applied (cancer, coronary heart disease, hypertension, stroke, diabetes, depression, etc). By no means should this suggest that specific applications are irrelevant. Without doubt an electrical engineer who works mostly on missile guidance systems will gain important expertise not shared by a comparable engineer who works primarily on aircraft communications systems. Our approach has been to catalog applications (or content elements) separately and to develop efficient methods for matching skills with applications in any combination. This simplifies the skills lexicon. At the same time this approach increases the flexibility and precision of the skills inventorying process.
We'd like to offer a few words about the two segments that set the size extremes. Why does ACADEMIA have 26 clusters and contain more than 53% of the skill descriptors whereas RELIGION has few clusters and just about 1% of the skill descriptors? This imbalance may expose analytical deficiencies which could be corrected in future Directory editions. Be this as it may, we have intended that RELIGION remain sparse in order to preclude any possibility of suggesting a narrow or biased interpretation of what should be included. The sparseness of the segment hopefully will encourage diverse interpretations of what is relevant to the human spirit and to the religious institutions and practices of mankind.