• Algorithm:
  • An unambiguous process (i.e., ordered set of steps) for solving a problem using a finite amount of resources
• Heuristic:
  • A problem solving process that is not guaranteed to be perfect/exact

• Algorithm:
  • The Oxford English Dictionary (OED) says it was first used with this meaning in 1811 (but as early as 1658 with similar meanings)
  • Some believe that the word is derived from the name of a Persian mathematics teacher named Muhammad ibn-Musa al-Khowarizm, one of the first people to develop step-by-step procedures for doing computations
• Heuristic:
  • The OED says it was first used with this meaning in 1957 (but as early as 1770 with similar meanings)
  • It may come from the Latin word meaning "ultimately" or the Greek word meaning "find" (and hence is sometimes used only for processes that learn/discover)

• Taken from a Shampoo Bottle:

  •             Wet your hair
                Apply shampoo
                Lather
                Rinse
                Repeat
              

• Questions:
  • Is it a set of steps?
  • Is it an algorithm, a heuristic, or neither?

• In Some Situations:
  • They are a recording/reporting of what is already known
• In Other Situations:
  • They must be discovered/invented

• Bloom's (Updated) Taxonomy of the Cognitive Domain:
  • Creating
  • Evaluating
  • Analyzing
  • Applying
  • Understanding
  • Remembering
• Algorithm Development:
  • Is not the regurgitation of memorized processes
  • Is about evaluating existing processes and creating new ones

• Science:
  • Involves the use of the scientific method (hypothesize, predict, and experiment)
• Engineering:
  • The application of science
• Algorithm Development:
  • Part science, part engineering, and a little art
  • 
    (Courtesy of Hackles)

• Describe what you would do:
  • Think about how you would solve the problem
  • Record the steps in the process you would use
  • Verify that the algorithm works
• Describe what you do as you do it:
  • Solve the problem recording the steps you use as you perform them
  • Verify that the algorithm works
• Describe what you did:
  • Solve the problem
  • Record the steps you used
  • Verify that the algorithm works

• Look for related problems/algorithms (i.e., patterns)
  • More general problems/algorithms
  • More specific problems/algorithms
  • Analogous problems/algorithms
• Look for "subproblems"
  • Partition the data
  • Divide the problem

• Decomposition:
  • Large algorithms are often broken down into a collection of smaller sub-algorithms (using abstraction)
• Input:
  • Information is often obtained from external "producers" (e.g., users, sensors)
• Memory/Recall:
  • Information often needs to be stored and recalled
• Operations:
  • Information is often manipulated (e.g., added, concatenated)

• Conditions:
  • Operations are often performed under some circumstances but not others
• Iterations:
  • Operations are often performed repeatedly/iteratively
• Output:
  • Information is often presented to external "consumers" (e.g., users, devices)

• Abstraction Defined:
  • "The act or process of separating in thought, of considering a thing independently..." (OED)
• Using Abstraction:
  • Focus on what is important
  • Ignore/hide unnecessary details
  • Leads to top-down development (treating some things as "black boxes")

  Prepare Hollandaise sauce
  Toast English muffin
  Poach eggs until whites are soft
  Grill Canadian bacon
  Plate the completed dish
  

  Heat butter until bubbling
  Combine all other ingredients in blender
  Pour butter into running blender in a slow stream
  

  Put butter in pot
  Turn on burner
  Put pot on burner
  While not bubbling, leave pot on burner
  Remove pot from burner
  If you like spicy sauce, put tabasco sauce in blender
  Put all other ingredients in blender
  Turn on blender
  While you have butter, pour butter into blender in a slow stream
  Turn off blender