The l imitations of diagnostic "accuracy " as a measure of decision performance require introduction of the concepts of the "sensit iv ity " and "specif ic i ty " of a diagnostic test, These measures and the related in-dices, "true positive fraction " and "false positive frac-t ion, " are more meaningful than "'accuracy, " yet do not provide a unique description of diagnostic perfor-mance because they depend on the arbitrary selection of a decision threshold. The receiver operating characteristic (ROC) curve is shown to be a simple yet complete empirical description of this decision threshold effect, indicating all possible combinations of the relative frequencies of the various kinds of cor-rect and incorrect decisions. Practical experimental techniques for measuring ROC curves are described,

The performance of present-day informational technologies has two main properties: the universality of the structures used and the flexibility of the final user’s interfaces. The first determines the potential cover area of the informational domain. The second determines the diversity and efficiency of processing methods of the proceedings being automated. The mentioned aspects are of great importance in agriculture and ecology because there are complex processes and considerable volumes of used information. For example, the meteoro-logical processes are a part of the ecological one like habitats ’ existential conditions and are known as a complex prognostic problem. The latter needs considerable computational re-sources to solve the appropriate equations. Likewise, agriculture as a controlled activity un-der strong impact from natural conditions has the same high requirements for diverse struc-tures and flexibility of information processing.

Identity criteria: x = y if and ony if.... — Material objects x and y are identical if and only if... — Events x and y are identical if and only if... — Properties x and y are identical if and only if... Metaphysical criteria vs formal-ontological principles

Stored & operated on in general registers Signed vs. unsigned depends on instructions used Intel GAS Bytes C byte b 1 [unsigned] char word w 2 [unsigned] short double word l 4 [unsigned] int

� Stored & operated on in general registers � Signed vs. unsigned depends on instructions used Intel GAS Bytes C byte b 1 [unsigned] char word w 2 [unsigned] short double word l 4 [unsigned] int quad word q 8 [unsigned] long int (x86-64)

n Stored & operated on in general registers n Signed vs. unsigned depends on instructions used Intel GAS Bytes C byte b 1 [unsigned] char word w 2 [unsigned] short double word l 4 [unsigned] int

� Stored & operated on in general registers � Signed vs. unsigned depends on instructions used Intel GAS Bytes C byte b 1 [unsigned] char word w 2 [unsigned] short double word l 4 [unsigned] int quad word q 8 [unsigned] long int (x86-64)

From the expression... pull oneself up by one’s bootstraps Thought to derive from the

� Stored & operated on in general registers � Signed vs. unsigned depends on instructions used Intel GAS Bytes C byte b 1 [unsigned] char word w 2 [unsigned] short double word l 4 [unsigned] int

The purpose of this article is to give a general overview on the basic principles and the implementation of one of the most recent learning techniques such as “Collaborative Learning”. More than thirty years on, it is interesting to look at the legacy of the communicative approach and to observe