1.2What is data visualization?

Introduction to data visualization

Data visualizationis the display of data in a format, such as a table or chart, that seeks to achieve a goal of conveying particular information to a viewer. Data presented in a text-only format often does not convey information well. Ex: Given this text-only data on 2013 median house prices in southern California counties, finding the price for a particular county is inconvenient: Los Angeles$405,000; Orange$661,000; Riverside$306,000; San Bernardino$192,000; San Diego$473,000; Ventura$464,000.

Instead, displaying the data visually as a table better conveys the information. Atabledisplays data using rows and columns.

Table 1.2.1: Southern California median house prices by county (2013).

County	Median house price
Los Angeles	$405,000
Orange	$661,000
Riverside	$306,000
San Bernardino	$192,000
San Diego	$473,000
Ventura	$464,000

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As another example, the following data represents California median house prices from 2000-2010: 2000$241,000; 2001$262,000; 2002$316,000; 2003$372,000; 2004$451,000; 2005$523,000; 2006$556,000; 2007$560,000; 2008$348,000; 2009$275,000; 2010$305,000. A table conveys the information better than text, but if the goal is to illustrate the housing price "bubble" that grew and then burst in 2008, a chart is even better.

Table 1.2.2: California median house prices, 2000-2010.

Year	California median house price
2000	$241,000
2001	$262,000
2002	$316,000
2003	$372,000
2004	$451,000
2005	$523,000
2006	$556,000
2007	$560,000
2008	$348,000
2009	$275,000
2010	$305,000

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Figure 1.2.1: California median house prices, 2000-2010.

Refer to the tables and charts above.

1)

Refer to the table above showing Southern California median house prices by county (2013). A company is considering moving offices to San Bernardino county. What is the median house price in that county?

2)

Refer to the table above showing California house prices from 2000-2010. In what year did the price bubble burst? That is, in what year was the price drastically lower than the previous year?

3)

Refer to the figure above showing California house prices from 2000-2010. In what year was the peak of house prices?

4)

Referring to the figure above showing California house prices from 2000-2010, what was the relative difference between the highest and lowest California house prices? Answer with: double, triple, or quadruple.