###Members: Joel D. Rodriguez-Ortiz ###Discussion Questions
1. Use an identity channel to express how-much.
a. Describe how this makes the chart difficult to interpret.
We naturally use relative judgement to measure quantities. We can tell A is bigger than B or C and D are more or less the same, but we have a hard time determining precisely by how much. Using the identity channel to encode how-much completely obliterates our relative judgement. Where we would expect bigger quantities to look bigger and smaller quantities to look smaller, everything in this chart looks the same in relation to each other. To determine the actual values of the different marks the eyes have to move back and forth between the mark and the legend many times. To make matters even worse I deliberately mismatched encoded quantity colors and fruit types (e.g., red bananas, yellow grapes). Another question that arises from using identity to express how-much is How do you encode intermediate quantities (35 Dates).
2. Revise chart 1 to use the proper type of channel to express how-much.
a. Describe how this makes the chart more effective.
This chart takes advantage of our relative judgement to directly answer the question being asked, how-much. We can immediately tell there are more Grapes than Strawberries and less Oranges than Dates. If we cared to know precisely how much of each we have left we could take a look at the axes and the different labels. This chart communicates magnitude in a way we can easily judge, making the encoding more effective than the first.
3. Use magnitude to express what/where.
a. Describe how this makes the chart difficult to interpret.
This chart encodes identity inefficiently because all of the squares look the same. Or, quite literally, all of the squares appear to have the same identity. Some look bigger than others, but they all appear to be the same type. To discover the meanings of the sizes one has to look at the legend. Then upon realizing the meaning of the sizes you require precise and subtle measurements to properly identify how large is one square in relation to another. One square clearly looks larger than the rest, but it's really hard to tell whether this square identifies Dates or Watermelons.
4. Revise chart 3 to use the proper type of channel to express what/where.
a. Desribe how this makes the graph more effective.
Using the proper channels to encode the proper attributes really allows communicating information much more effectively. Using the magnitude channel to encode quantities and the identity channel to encode type and class information allows precise delivery of the information being portrayed. By mapping the type of fruit to distinct colors an initial chart viewer might not know exactly the type of each of the bars, but they'll certainly know they're different. By associating the actual item colors to their real-world related colors, we can help the user memorize their encoding much quicker (minimizing legend use). Lastly I wanted to point out that using the proper encodings I was able to pack much more information into this last chart than to any of the other charts. I was able to plot the types of fruit in stock (identity) and exactly how much we have in stock (magnitude), delivering all of this information much more efficiently (and in a smaller chart.)