Computational Thinking

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Computational Thinking

• What is it?Computer Science Unplugged

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Computational Thinking (CT)(from Jeannette
Wings website)

• Computational thinking will be a fundamental
  skill used by everyone in the world by the middle
  of the 21st Century.
• J.M. Wing, Computational Thinking, CACM
  Viewpoint, March 2006, pp. 33-35.
• http//www.cs.cmu.edu/wing/

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Examples of CT(from Jeannette Wings website)

• Determining how difficult a problem is to solve.
  Thinking recursively.
• Choosing an appropriate representation for data
  to simplify the solution to problems.
• Reformulating a seemingly difficult problem into
  one which we know how to solve.
• Using abstraction and decomposition in tackling a
  large complex task.
• Using the difficulty of solving hard AI problems
  to foil computing agents.

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Examples of CT in daily life(from Jeannette
Wings website)

• Sorting important documents.
• Choosing a line at the supermarket. (queuing and
  scheduling)
• Putting things in your childs knapsack for the
  day. (caching)
• Running errands (Traveling salesperson)
• Cooking dinner or washing loads of laundry
  (parallel processing/pipelining)

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CT in STEM(from Jeannette Wings website)

• Biology
• Shotgun algorithm expedites sequencing of human
  genome
• DNA sequences are strings in a language
• Brain Science
• Analyzing fMRI data with machine learning
  algorithms
• Chemistry
• Optimization and searching algorithms identify
  best chemicals for improving reaction conditions
  to improve yields

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CT in STEM(from Jeannette Wings website)

• Earth Science
• Modeling the earth or the sun inner core,
  surface, atmosphere
• Astronomy
• Sloan Digital Sky Server brings a telescope to
  every child
• Mathematics
• Discovering E8 Lie Group Profound implications
  for physics (string theory)
• Engineering
• Boeing 777 tested via computer simulation alone,
  not in a wind tunnel

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Computational ThinkingAn Operational Definition
for K-12

• Computational thinking (CT) is a problem-solving
  process that includes (but is not limited to) the
  following characteristics
• Formulating problems in a way that enables us to
  use a computer and other tools to help solve
  them.
• Logically organizing and analyzing data
• Representing data through abstractions such as
  models and simulations
• Automating solutions through algorithmic thinking
  (a series of ordered steps)
• Identifying, analyzing, and implementing possible
  solutions with the goal of achieving the most
  efficient and effective combination of steps and
  resources
• Generalizing and transferring this problem
  solving process to a wide variety of problems

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Computational ThinkingAn Operational Definition
for K-12

• These skills are supported and enhanced by a
  number of dispositions or attitudes that are
  essential dimensions of CT. These dispositions or
  attitudes include
• Confidence in dealing with complexity
• Persistence in working with difficult problems
• Tolerance for ambiguity
• The ability to deal with open ended problems
• The ability to communicate and work with others
  to achieve a common goal or solution

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Computer Science Unplugged
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Count The Dots

• Data in computers is stored and transmitted as a
  series of zeros and ones.
• How can we represent words and numbers using just
  these two symbols?

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Count The Dots

• Letters are represented in computers in binary
  also.
• Blank 0 000002
• A 1 000012
• B 2 000102
• C 3 000112
• ...
• Z 26 110102

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Count The Dots

• 01001
• 00011
• 00101
• 00000
• 00011
• 10010
• 00101
• 00001
• 01101

I C E _ C R E A M
blank 0 A 1 B 2 C 3 D 4 E 5 F 6 G 7 H 8 I
9 J 10 K 11 L 12 M 13
N 14 O 15 P 16 Q 17 R 18 S 19 T 20 U 21 V
22 W 23 X 24 Y 25 Z 26
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Color By Numbers

• Computer screens are divided up into a grid of
  small dots called pixels (picture elements). In a
  black and white picture, each pixel is either
  black or white.
• Computers store drawings, photographs and other
  pictures using only numbers.
• The following activity demonstrates how a
  computer image can be stored efficiently.

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Color By Numbers

• The letter a has been magnified to show the
  pixels. When a computer stores a picture, all
  that it needs to store is which dots are black
  and which are white.

1,3 4,1 1,4 0,1,3,1 0,1,3,1 1,4






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Color By Numbers
6,5,2,3 4,2,5,2,3,1 3,1,9,1,2,1 3,1,9,1,1,1 2,1,11
,1 2,1,10,2 2,1,9,1,1,1 2,1,8,1,2,1 2,1,7,1,3,1 1,
1,1,1,4,2,3,1 0,1,2,1,2,2,5,1 0,1,3,2,5,2 1,3,2,5






















































































































































































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Color By Numbers

• This technique is called run-length encoding.
• Fax transmission
• Compression of images
• Color encoding
• Use two numbers per run
• First number is how many pixels as before
• Second number is what color (1red, 2green, ...)

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Information Theory

• How much information is there in a book? Is there
  more information in a telephone book, or in Harry
  Potter and the Deathly Hallows?
• If we can measure this, we can estimate how much
  space is needed to store the information.
• Can you read the following sentence?
• Ths sntnc hs th vwls mssng.

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Twenty Guesses

• I am thinking of a number between0 and 127.
• You may only ask questions that have a "yes" or
  "no" answer.
• For each question, you will lose one piece of
  candy.
• Once you guess the number correctly, you can
  keep whatever candy remains.

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Twenty Guesses

• To pick a number between 0 and 127, you only need
  7 guesses.
• Always shoot for the middle number of the range
  and eliminate half the possibilities!
• This concept is called binary search.
• If the number was between 0 and 1,023, you would
  only need 3 additional guesses.
• You can guess a number between 0 and 1,048,575
  in only 20 guesses!

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Beat The Clock