The
nature of data and information –
Data is the input and raw material of an
information system. Information is the output of the information system and it
is made meaningful and untestable for the user. The information that is
outputted from an information system can be used as the data going into further
information systems. The data and information used by information systems are
different types, each fitted to different tasks.
Different Types of Media
Media refers to something in the middle
that is used to transmit a message of some sort. There are five different types
of media that can be used by information systems. These types are text,
numbers, image, audio and video and these media provide a method of
representing data.
Text
The text media type is used to represent
characters and these characters can be printable or non-printable. An order of
characters is used to represent words, paragraphs and complete books it also
can be used for other purposes. Another purpose is used in a telephone book to
store phone numbers and the orders of the characters appear is vital. There are
different methods for representing text digitally; the two most common methods
are ASCII and EBCDIC. ASCII stands for American standard code for information
interchange and EBCDIC stands for extended binary coded decimal interchange
code. Mid-range computers use EBCDIC to communicate with other devices. ASCII
system is more widely used and has become the standard for representing text
digitally.
Numbers
The number media type is used to represent integers (whole numbers), real numbers (decimals), currency and even dates and
times. All data stored and processed by a digital computer is all represented
as numbers. We call this binary numbers, binary numbers are processed by adding
and comparing them. All media types are represented and processed as binary
number to make it easier for computers to process with. Different information
systems and their processes require different methods of representing numbers
are in common usage.
Integers
Integers are represented using the two’s complement system, this system codes the sign of
each number in a way that binary calculations don’t need the sign of the
numbers. Integer is represented using either 16 bits or 32 bits and the 16 bit
integers range is from -32768 to 32767. The 32 bit integers range from
-2147483648 to 2147483647. Whole number calculations which fall in the range are
perfectly accurate however calculations not in the range are impossible.
Real Numbers
Real numbers are well known as ‘floating-point’ in a system and are represented using
a technique similar to scientific notation. There are two common standards;
single precision floating-point and double precision floating-point.
Floating-point calculations are more processor intensive than integer
calculations and most CPU designs have a dedicated floating-point unit.
Currency
Financial calculations need very precise calculations but within a relatively restricted
range. Most currency calculations accuracy has to be up to two decimal places to
be perfect and a similar system to integer representation is used.
Each data item is represented using 64 bits (8 bytes) and every decimal
number with up to four decimal places, can be represented precisely within the
range.
·
Dates/Times
Systems code dates and times using separate number for the day, month, year and time.
It is frequent for a single date and time to be represented as a
double-precision floating-point number. The method of representation is the same
to the double precision floating-point system. The analyzing process turns the
numbers into dates and times so people can understand.
Images
Images are used to represent data that will
be displayed as visual information. Information that are displayed on monitors
and printed as hardcopy is images. Text and numbers are sorted into image data
only preparation for display. Photographs and other graphical images are
designed specially to display. There are two different techniques for
representing images; bitmap and vector.
·
Vector
Vector images represent each
portion of the image mathematically and each shape in a vector image is a
separate object that can be changed without affecting the other objects. Vector
images can be resized to any resolution without loss of clarity and without
increasing the size of the data. Vector images are not suitable to display
photographic images because the detail required is hard to reproduce
mathematically.
Bitmap
Bitmap images represent each element or dot as we call pixels in the picture
separately. Each pixel can be a different colour and binary numbers are used to
represent each pixel. The overall size of the binary representation depends on
the number of colours shown in an image. Most colour images can have up to
sixteen million different colours, where each is represented using 24 bits.
Audio
The audio media type is used to represent
sound this includes music, sound effects, speech or even a simple ‘beep’. Sound
waves transmit sound by compression and decompression of molecules. All waves
must have a frequency and amplitude and frequency is measured in hertz (Hz).
Frequency is the number of times per second that a complete wavelength occurs
and amplitude determines the volume or loudness of the sound. Very low
amplitude waves are really and can’t be heard but high amplitude waves can
damage waves. Amplitude is measured in decibels (db) and they have no absolute
value. Audio or sound can be represented in binary and there are two methods,
sampling and individual notes. Sampling is used when converting real sound wave
where as individual notes is used for computer generated sound.
Sampling
Each sample is stored as a binary number and it results in a large number of points
to create an approximate shape of the original sound wave. There are parameters
that have an impact on the accuracy and quality of audio samples; the number of
samples each second and numbers of bits per second.
Individual Notes
The position of each note on a music score determines its pitch and the symbol used
determines its duration. The most common storage format for such files is the
MIDI (Musical Instruments Digital Interface). Certain instruments can be
specified to play each series of notes and binary representations that use
individual notes are significantly smaller than smaller sound samples.
Video
The video media type combines image and
sound data together to create information in form of movies and animation.
Images going into the human eye persist approximately on twentieth of a second.
Video data is made of multiple images put together with an optional sound
track. All the information must be represented in a specific way so we can the
viewer can understand it. There are techniques to represent video in binary and
as we know the images in their raw form are represented as bitmaps.
nature of data and information –
Data is the input and raw material of an
information system. Information is the output of the information system and it
is made meaningful and untestable for the user. The information that is
outputted from an information system can be used as the data going into further
information systems. The data and information used by information systems are
different types, each fitted to different tasks.
Different Types of Media
Media refers to something in the middle
that is used to transmit a message of some sort. There are five different types
of media that can be used by information systems. These types are text,
numbers, image, audio and video and these media provide a method of
representing data.
Text
The text media type is used to represent
characters and these characters can be printable or non-printable. An order of
characters is used to represent words, paragraphs and complete books it also
can be used for other purposes. Another purpose is used in a telephone book to
store phone numbers and the orders of the characters appear is vital. There are
different methods for representing text digitally; the two most common methods
are ASCII and EBCDIC. ASCII stands for American standard code for information
interchange and EBCDIC stands for extended binary coded decimal interchange
code. Mid-range computers use EBCDIC to communicate with other devices. ASCII
system is more widely used and has become the standard for representing text
digitally.
Numbers
The number media type is used to represent integers (whole numbers), real numbers (decimals), currency and even dates and
times. All data stored and processed by a digital computer is all represented
as numbers. We call this binary numbers, binary numbers are processed by adding
and comparing them. All media types are represented and processed as binary
number to make it easier for computers to process with. Different information
systems and their processes require different methods of representing numbers
are in common usage.
Integers
Integers are represented using the two’s complement system, this system codes the sign of
each number in a way that binary calculations don’t need the sign of the
numbers. Integer is represented using either 16 bits or 32 bits and the 16 bit
integers range is from -32768 to 32767. The 32 bit integers range from
-2147483648 to 2147483647. Whole number calculations which fall in the range are
perfectly accurate however calculations not in the range are impossible.
Real Numbers
Real numbers are well known as ‘floating-point’ in a system and are represented using
a technique similar to scientific notation. There are two common standards;
single precision floating-point and double precision floating-point.
Floating-point calculations are more processor intensive than integer
calculations and most CPU designs have a dedicated floating-point unit.
Currency
Financial calculations need very precise calculations but within a relatively restricted
range. Most currency calculations accuracy has to be up to two decimal places to
be perfect and a similar system to integer representation is used.
Each data item is represented using 64 bits (8 bytes) and every decimal
number with up to four decimal places, can be represented precisely within the
range.
·
Dates/Times
Systems code dates and times using separate number for the day, month, year and time.
It is frequent for a single date and time to be represented as a
double-precision floating-point number. The method of representation is the same
to the double precision floating-point system. The analyzing process turns the
numbers into dates and times so people can understand.
Images
Images are used to represent data that will
be displayed as visual information. Information that are displayed on monitors
and printed as hardcopy is images. Text and numbers are sorted into image data
only preparation for display. Photographs and other graphical images are
designed specially to display. There are two different techniques for
representing images; bitmap and vector.
·
Vector
Vector images represent each
portion of the image mathematically and each shape in a vector image is a
separate object that can be changed without affecting the other objects. Vector
images can be resized to any resolution without loss of clarity and without
increasing the size of the data. Vector images are not suitable to display
photographic images because the detail required is hard to reproduce
mathematically.
Bitmap
Bitmap images represent each element or dot as we call pixels in the picture
separately. Each pixel can be a different colour and binary numbers are used to
represent each pixel. The overall size of the binary representation depends on
the number of colours shown in an image. Most colour images can have up to
sixteen million different colours, where each is represented using 24 bits.
Audio
The audio media type is used to represent
sound this includes music, sound effects, speech or even a simple ‘beep’. Sound
waves transmit sound by compression and decompression of molecules. All waves
must have a frequency and amplitude and frequency is measured in hertz (Hz).
Frequency is the number of times per second that a complete wavelength occurs
and amplitude determines the volume or loudness of the sound. Very low
amplitude waves are really and can’t be heard but high amplitude waves can
damage waves. Amplitude is measured in decibels (db) and they have no absolute
value. Audio or sound can be represented in binary and there are two methods,
sampling and individual notes. Sampling is used when converting real sound wave
where as individual notes is used for computer generated sound.
Sampling
Each sample is stored as a binary number and it results in a large number of points
to create an approximate shape of the original sound wave. There are parameters
that have an impact on the accuracy and quality of audio samples; the number of
samples each second and numbers of bits per second.
Individual Notes
The position of each note on a music score determines its pitch and the symbol used
determines its duration. The most common storage format for such files is the
MIDI (Musical Instruments Digital Interface). Certain instruments can be
specified to play each series of notes and binary representations that use
individual notes are significantly smaller than smaller sound samples.
Video
The video media type combines image and
sound data together to create information in form of movies and animation.
Images going into the human eye persist approximately on twentieth of a second.
Video data is made of multiple images put together with an optional sound
track. All the information must be represented in a specific way so we can the
viewer can understand it. There are techniques to represent video in binary and
as we know the images in their raw form are represented as bitmaps.