Transcript Course overview

Data + code → information
Skills: none
Concepts: data, information, code, code
standardization, encoding text, information and
variety
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3.0 License.
Where does this topic fit?
• Internet concepts
– Applications
– Technology
– Implications
• Internet skills
– Application development
– Content creation
– User skills
All data is binary
010101011100101010101010101010111010
101010101010101010101010100101010101
000010110101010101010010101101101010
101010110010110010101010100101110101
001010010101010101010001001010101011
010011010010101010100101101001011100
101010101001010101000101010101010101
010010101001010101001001001001010101
001000101010101110100101001010101010
010101010101001010100100101010010101
001001010101001010100101010100101010
101001010101011110101011100001111011
40 bits of data
0100110001100001011100100111001001111001
What data type is this – image? Video? Audio? Text? These
bits are not random – do you see a pattern or clue to a code?
5 bytes of data
0100110001100001011100100111001001111001
01001100
01100001
01110010
Do you see any pattern or regularity now?
01110010
01111001
5 bytes of data
0100110001100001011100100111001001111001
01001100
01100001
01110010
01110010
What can you conclude from these two codes being the same?
01111001
A code for text data
Data + a code → information
0100110001100001011100100111001001111001
L
L
01001100
a
01100001
r
01110010
r
01110010
y
01111001
a
r
r
y
Many bits, no information
010101011100101010101010101010111010
101010101010101010101010100101010101
000010110101010101010010101101101010
101010110010110010101010100101110101
001010010101010101010001001010101011
010011010010101010100101101001011100
101010101001010101000101010101010101
010010101001010101001001001001010101
001000101010101110100101001010101010
010101010101001010100100101010010101
001001010101001010100101010100101010
101001010101011110101011100001111011
One bit can convey information
0 = male
1 = female
Standardization
Fail
0 = male
1 = female
1 = male
0 = female
International Organization for Standardization ISO-8859-1
Any camera and viewing program
JPEG
BMP
PNG
GIF
Etc.
MY NAME IS LARRY PRESS.
My name is Larry Press.
Which sentence conveys the most information – one made up
of only upper case characters or one made up of upper and
lower case characters?
Codes before computers
Paul Revere’s one-bit message
= By land (0)
= By sea (1)
Encoding text
Data type
Decade
Numeric
1950s
Alphanumeric
1960s
Text
1970s
Image
1990s
Speech
2000s
Music
2000s
Video
2000s
HD video
2010s
Could you devise a code of 1s and 0s to represent this image?
Summary
Data + a code → information
Resources
International Organization for Standardization:
http://www.iso.org/iso/home.html
ISO 8859-1 character standard:
http://en.wikipedia.org/wiki/ISO/IEC_8859-1
Paul Revere’s 1-bit message:
http://en.wikipedia.org/wiki/Paul_Revere#The_Midnight_Ride_
of_Paul_Revere
Self-study questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
What would happen if a program tried to display a page of text that
was created by a program using a different code than expected?
If you took a picture of your car, could you store that using the ISO
8859-1 character standard? Explain your answer.
Write the word Hello using the ISO 8859-1 character standard.
a. How many bits did it take?
b. How many bytes did it take?
c. Would it take more bytes in memory than in storage?
At 10 bits per second, how long would it take to transmit Hello from
one computer to another?
How long would it take at 10 megabits per second?
Would the word Hello be encoded the same as the word hello?
Would it take longer to transfer the word hello from storage to
memory than the word Larry?
How many bits long was Paul Revere’s message? Explain your answer.
Which contains more information 100 random bits or 1,000 random
bits? Explain your answer.
9. The symbols 0…9 may be used in numeric and text data. Which
of these is numeric and which is text?
Height (inches)
Weight (pounds)
Social security number
70
170
544678793