Tenenbaum & Augenstein on Data, Information, & Semantics
Last Update: 27 February 2010
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Some quotations from:
Tenenbaum, Aaron M.,
Augenstein, Moshe J.
Data Structures using Pascal
(Englewood Cliffs, NJ: Prentice-Hall).
"...computer science is fundamentally the study of information...." (1).
"...the concept of information in computer science is similar to the
concepts of point, line, and plane in geometry
they are all undefined
terms about which statements can be made but which cannot be explained in
terms of more elementary concepts." (1)
"The basic unit of information is the bit, whose value asserts one
of two mutually exclusive possibilities." (1)
|"…information itself has no meaning. |
Any meaning can be assigned to a
particular bit pattern as long as it is done consistently.
It is the
interpretation of a bit pattern that gives it meaning." (6)
"A method of interpreting a bit pattern is often called a data type.
"It is by means of declarations [in a high-level language] that the programmer
how the contents of the computer memory are to be interpreted by
the program." (8)
"Thus far, we have been viewing data types as a method of interpreting the
memory contents of a computer.
…However, we can view the concept of
"data type" from a completely different perspective
not in terms of what
a computer can do, but in terms of what the user wants done." (8)
"A data type is an abstract concept defined by a set of logical
Once such an abstract data type is defined and the legal
operations involving that type are specified, we may implement that
An implementation may be a hardware implementation,
in which the circuitry necessary to perform the required operations is
designed and constructed as part of a computer. Or it may be a
in which a program consisting of already
existing hardware instructions is written
to interpret bit strings in the
desired fashion and to perform the required operations." (8)
"…a type is a method for interpreting a portion of memory.
variable identifier is declared as being of a certain type,
we are saying
that the identifier refers to a certain portion of memory
and that the
contents of that memory are to be interpreted according to the pattern
defined by the type." (45)
For more on the relation of syntax to semantics, see:
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