The 20th century has marked the transformation of the philosophical definition of knowledge into a new and different one. The new idea of knowledge mostly depends on the experiences and theories from human and social sciences like psychology, pedagogy, anthropology, sociology, and so forth. But many contributions to its specification are also due to biology, neurophysiology, telecommunication, cybernetics, and other scientific disciplines. In other words knowledge is today a complex matter and its analysis and definition depends on the observation fields one can use for its analysis.
Knowledge And Individuals
J. Piaget (1971, 1973) and D. P. Ausubel (1990) are among the first scientists stating the importance of subjects’ mental actions in cognitive processes. They assign a great role to the subject-reality interaction for the explanation of knowledge development and evolution; for this reason they are also considered cognitivists and precursors of constructivism (they are usually classified as the first interactive constructivists). They, on another hand, assign a little or no role to social and cultural interactions in knowledge construction and evolution. The ideas from J. Piaget and D. P. Ausubel have been verified, integrated and, sometimes, contradicted from further scientist but have retained all their importance for the role they assigned to individuals in knowledge management and development.
On a different basis moved D. H. Jonassen (1994), who founded the project of learning environments on the following statements: (a) knowledge construction is based on individual and social influences, (b) meaningful contexts support problem solving skills (which have to be derived from real situations), (c) cooperation between student and teacher and among peers is at the basis of learning processes. He also suggested the idea of cognitive apprenticeship as a teaching-learning strategy strongly based on the experience and the reflection on it.
Further studies introduced the concepts of multiple intelligence (Gardner, 1993), learning styles (Mc Lellan, 1996) and cognitive flexibility (Spiro & Jehng, 1990), to consider the complexity of the cognitive phenomenon into individuals.
The importance of context and social effects on individuals’ knowledge construction and development has been stated in many other studies, often under the influence of L. Vygotskij and A. N. Leont’ev hypotheses (Varisco, 2002). The first assigns a leading role to language and social interactions and hypothesizes the presence of ZSP (zones of proximal development) to mark the differences existing among the differently skilled subjects in a community. The latter is better known for his activity theory, where subjects work on objects in order to obtain a desired outcome; to do this people employ tools, which may be external (i.e., a material instrument) or internal (plans, etc.). Y. Engeström (1987) proposes a scheme of activity different from that by Leont’ev because it contains three interacting entities: the individual, the object, and the community.
Key Terms in this Chapter
Round Trip Time (RTT): The time period that is necessary for sending a packet from the sender to the receiver and for sending it from the receiver to the sender.
Goodput: The bandwidth of the useful packets at the receiver side, which is also called the effective receiving rate.
TCP (Transmission Control Protocol): Widely used for bulk data transmission. It is suitable for file transfer, but not for streaming media transmission.
Congestion Control: A mechanism that can be built into a protocol. Its main goal is to help the data transmission to avoid the overflow in the buffers of the routers inside the network.
IP-Multicast: Network-level multicast technology, which uses the special class-D IP-address range. It requires multicast routing protocols in the network routers. Its other nameis network-level multicast (NLM).
Reliability: The improved quality of data transmission. Different types of reliability exist, including data accuracy or real-time delivery.
Transport Layer: This is an abstraction; the protocol belonging to the transport layer is responsible for the port handling and sometimes the improved reliability of the transmission.
TTL (Time-to-Live): A field in the IP packet header. Its value is the allowed hop-count, the number of routers, which can forward the packet before delivery or dropping out.
Port Handling: From the network, the processes running in a computer can be addressed with an integer number between 0...65535 called port. Some port numbers are mapped steadily to important applications. They are called well-known port numbers. For example, the Web server typically uses the port number 80.
Data Stream Applications: The class of large receiver set, low bandwidth real-time data applications.