3001. Look at Figure 1 again. Where does the figure begin and the white space of the page end? How can you tell?

We call this place where one thing ends and another begins a boundary. Write a rule that would tell a computer how to locate the boundary of Figure 1? Extend the rule to find the boundaries within the two parts of Figure 2 and between the figure and the page. Why is this so much harder to do?

Consider the boundary between the room in which you are sitting and the next room. Can you write a rule to locate that boundary? [This is a very difficult question -- consider: when you walk from room to room when have you left one and entered the other? Are you sometimes in both at once? In that case, how does the boundary move across your body?]

3002. Look at Figure 4. Does it seem to be tilted slightly to the right? Although it isn't (how would you prove that?), it may appear so. The study of optical illusions demonstrates that what we see with the "naked eye" is not always true. Find some books in your library that deal with this subject and discuss whether or not our senses provide us with "real" data about the world.

3003. In Figure 4 two of the light lines are closer together than any of the others. Did you notice this pattern previously? Why or why not? How does the existence of this pattern complicate our attempt to write a set of production rules for the figure?

3004. Notice that in the illustration that shows the first three patterns at once, the area that the patterns fill has been reduced. This has no effect on the first two rule sets (why?), but the rule set for the third is now incorrect. Rewrite the third rule set so that it accurately reproduces the pattern in terms of the relative sizes of the dark and light bands.

3005. Are three rules enough to specify the pattern in Figure 2? Don't we need a rule that requires the boundary to be straight up and down? Can you rewrite the rule set so that this new requirement is included, but only three rules are needed.

3006. In some card games it is possible to define a "wild" card or cards. Explain how wild cards relate to the "regular" rules of the game.

3007. Explain how the dotted and solid lines painted on a highway function as rules. What actions do they prohibit? What patterns do the allow?

3008. In the "traffic control" paradigm the syntagms both lights on and both lights off also have corresponding "driving behaviors." What are they?

3009. Notice that from the three-light paradigm of the traffic light, we are able to form eight syntagms. Why do we use only three of these in our traffic code?

The eight syntagms:

1	all of the lights off	(all off)
2	all of the lights on	(RYG)
3	Red on and others off	(R)
4	Yellow on and others off	(Y)
5	Green on and others off	(G)
6	Red and Yellow on and Green off	(RY)
7	Red and Green on and Yellow off	(RG)
8	Yellow and Green on and Red off	(YG)

What would be the disadvantage of having both green and red come on at the same time as the "about to change" code element?

3010. The two-color, red/green, stop light produces an unexpected (and undesirable) kind of pattern called a "collision." We set out to eliminate this pattern by adding additional rules and elements to the light. What kinds of additions to the code do we use to handle the following "unexpected" patterns that arise with the three-color light?

1. "Running" a light - i.e., failure to stop when the light is red.
2. An emergency vehicle, such as a fire truck or ambulance, that must be able to move even if the light is red.
3. Power failures - in which case the light is completely dark.

3012. Consider different patterns of the three traffic lights. There are three lights, and each can be in one of two conditions: either on or off. If we call the number of lights N, and the number of conditions C, we can compute the number of different patterns by using the formula N^C - in this case 3² = 8. To verify this, write down the patterns for a light box with 1, 2 and 4 lights and show that the count is the same as the value computed via the formula.

3013. In a room, two radios are playing - one in Japanese and one in English. There is a person sitting in the room. Discuss the concepts of data, information and noise in terms of this situation.

3014. Information is the process by which the receiver becomes less uncertain. Notice that false data can reduce uncertainty just as easily as true data. Invent three situations in which a receiver is given false data but is still informed.

3015. Communication that increases uncertainty is often referred to as disinformation. Just as one need not tell the truth to inform, one need not lie to disinform. Construct an example for each of the following situations of disinformation:

1. Purposely providing false data; lying.
2. Accidentally providing false data; making an error.
3. Providing accurate, but misleading, data.

3017. Imagine that you want to be able to talk to a friend in a dark, noisy place - too dark to see and too noisy to hear. The two of you decide to invent a "touch" code. You will communicate by tapping on each others' arms. The elements of the paradigm will be composed of periods of touching and periods of not-touching the receiver's arm.

You would like to be able to say these things

• yes
• no
• please repeat that
• go forward
• go backward
• stop
• turn right
• turn left

Suppose you decide to add one more element: "end of message." How will you have to alter the code?

3018. This diagram shows the kinship system of the Kariera people of Western Australia. A "kinship" system is a set of rules that constrains marriage and family relationships within a society. In this case there are four groups of people: A, B, C, D.

Based on Wilden, 106.

The "marriage" arrows describe possible marriage conditions, and the "children" arrows show which group the children will enter - for example, men of group B can only marry women of group D, and their children will belong to group C.

What is the paradigm for this code? Explain why this diagram is an example of a map.

3019. Abbreviation is a coding process that maps a word into a shorter, but still understandable word. Compile a list of typical abbreviations (a dictionary will often have such a list at its front) and try to discover some of the rules that make up the code.

3020. Make maps for the following rule sets.

1. The rules of "Paul Revere's Ride"
2. How you decide if your college GPA is "good," "OK," or "bad"
3. Behavior of traffic at an intersection with no traffic lights or stop signs

3022. We might simplify the rule set for Figure 4 by taking the "star-" or "snowflake-" shaped pattern, , to be one of the gray elements, and "circles", , and "bars", , to be the only others.

Then the rule set might be:

• Use no colors other than light and dark gray
• Place stars end-to-end
• Place circles between the top and bottom angle points of every other pair of stars
• Place bars at the intersection of every other pair of star
• Circles and bars may not be underneath one another.

This is an example of what is often called reduction. We have reduced the complexity of the pattern by breaking it into pieces and assuming that we will be able to discover rule sets for producing the pieces later.

Try to produce rule sets for the "circle," "bar," and "star." (You may find it worthwhile to further reduce the "star.")

3023. The box to the right of the "mobile" illustration is a map. What two paradigms are mapped, and what is the code?

3024. In our discussion of the traffic light we took a particular set of patterns as our paradigm. It might be interesting to notice that this paradigm was itself generated by a code that takes three colors, R-Y-G, and three positions, middle-up-down, as its paradigm. Write down the map for this code.

3025. A parent has established his child must be home by 10:00 PM on "school" nights, and has discussed with the child the need to complete homework and other studies before "going out." One Wednesday evening the child comes home at 10:30 PM to find an angry father waiting. "You're late," says the parent, "Where were you?" "Is your homework done?" "I had to stop by the Library," says the child. "Tomorrow's Saturday - there's no homework due."

1. Discuss the context of this conversation. Should both participants understand "where the other is coming from?"
2. Devise a scenario in which the child's answer would be informative.
3. Devise a scenario in which the child's answer would be disinformative.

1. the United States
2. China
3. Russia
4. Japan

3028. Explain how each of these might be produced by an coding process.

1. a student's fall schedule
2. a new federal law
3. a rainbow
4. an Emily Dickinson poem

1. The phone company compiles a "phone book"
2. A TV camera records something on tape
3. A student's GPA is computed
4. A digital clock displays the time
5. An artist draws a comic book

3030. Think about the ways in which you communicate with other people. How many "rules of human communication" can you discover?

3031. "Changing the Centralized Mind," by Mitchel Resnick in Technoogy Review, July 1994, discusses the notion of decentralized organization. This term refers to information processes that operate without any form of central control. Read this article and discuss its relevance to human communication.

3032. Choose one of the following codes. Research the code in depth. What are the paradigms that it connects? What meanings does it convey? How is the code used in human communication?

1. "standard American" bidding in the game of bridge
2. the signs of the zodiac astrological signs)
3. the metric system
4. the philosophical code of the Chinese I Ching
5. birthstones
6. the cards of the Tarot deck
7. "standard openings" in the game of chess
8. the years of the Chinese calendar
9. chemical formulas