Fall 2016 Computer Science 458 Lecture 2: 9/02/2016

1. Both function1 and function2 should print out the results (each
   line contains a single word), instead of returning them.

2. For function2, as shown in the example, the target word should not
   be included in the result.

3. For both functions, the case doesn't matter. 
   "Male" should be in the same group with "male" or "alme".

4. You can print any largest set, but not both.

5. For both functions, the program should ignore the characters other
   than "a -z", "A- Z" and "0-9".

By the way, the test cases we use are similar to the examples.  The
main goal of this homework is to test how well do you know Python and
R.  We will not use lots of corner cases to defeat your program.  Hope
it helps.

Do not use the Classes server dropbox. !!

Bottom line: we are not trying to create lots of gotcha cases. This is not a software engineering course. We want you to attain conversational fluency in R and Python. We do not expect you to be able to write bulletproof code.

Lecture

• Getting a tattoo.
• Voting for each of the presidential candidates.

• Stakeholders. Need to incorporate the views or reactions of people who are or will be affected by the choice. For the tattoo, this group includes friends, relatives, future employers, future spouse and in-laws, and future children.

• Consequences. What happens if you make a choice? What are the results? The consequences of getting a tattoo are likely more long lasting than the consequences of getting drunk. Although, you could get drunk, cause a car accident that results in serious injuries or death. This is a case of causality in reverse: the prospect of future outcomes alters the decisions you make today.

• Explanation. What are the reasons behind your decision? How would you explain or justify the decision? Would you have a different explanation for different people or at different times?

• Cost / Resources. What costs are associated with the decision? How expensive is the tattoo, pace Professor Spielman and the Petersen Graph? Costs need not be limited to economic costs. Other resources include time, agent relationships (asking a friend for a favor), reputation. Businesses explicitly consider the reputation risk associated with decisions. (How would this look on the front page of the Wall Street Journal?) See next.

• Risk. What risks are associated with the decision? Broadly speaking, this is another kind of cost. What if you make a mistake, and get the wrong Chinese character? Is it possible to mitigate the risk? For example, can you remove a tattoo?

  Every risk raises the question of a mitigation strategy. Removing a tattoo is an example. How does the presence or absence of a mitigation strategy affect a decision?

  Also, someone observed that the quality of the tattoo will degrade over time. I noted that the same could be said for your Yale education. Upon reflection, I believe that for most alums, their Yale experience improves with age. They do not have an eidetic or photgraphic memory. Personally, I have a photoshop memory.

• Precedent. Past decisions provide justifications for future choices. There is a presumption of consistency in decisions. I always vote for the Democrat.

• Societal Norm. A lot of decisions are explained by saying that this is the normal course of action. For example, a sailor would not be questioned for getting an anchor tattoo. Norms can be seen as a case of strong precedents. Also, different societies have different norms.

• Emotion. Sometimes the decision seems to be driven of the affect or emotion involved. Getting a tattoo can be impulsive, like buying candy at the checkout counter.

• Principles, Ethics, Beliefs, Religion. Getting a tattoo can preclude your admission to a Jewish cemetary. There are constellations of principles that can impinge on decisions.