MATH 1680 - Statistics - Chapter 2 Organizing and Summarizing Data - Section 2.4

Common Misrepresentations of Data Involve...

-Scale -Inconsistent Scale -Misplaced Origins -Incremetns between marks are not consistent -Scales for compartive graphs should be the same -The Baseline, aka zero point, should be ath the bottom of a graph because a graph that beigns at a higher or lower value than zero can be misleading

Why are 3-D graphs strongly discouraged?

-difficult to read -add little value -distract from data

What is wrong about a baseline that does not begin at zero?

-it makes the difference between two categories seem bigger than the actuality

If a politician wants to support the position that the health care expenditures are increasing and must be slowed what type of graph would they choose? -one whose baseline is zero and indicates increasing values -one whose baseline begins at a higher number with values that fluctuate ~ -one whose baseline is not zero and indicates the values have been increasing

-one whose baseline is not zero and indicates the values are increasing

If the health care industry wants to showcase taht the health care expenditures are not increasing and refute the previously mentioned politician, what graph might they use? --one whose baseline is not zero and indicates the values have been increasing -one whose baseline is not zero and values dramatically fluctuate from one year to the next -one whose baseline is zero and indicates the values are steady and consistent

-one whose baseline is zero and indicates the values are steady and consistent

Why are three-d graphs misrepresentatations of data?

-the category closes to us seems bigger -the angle of which you are viewing the pie chart distorts the sizing of each sector

Guidlines on Clutter/Distractions

Avoid clutter, such as excessive gridlines and unnecessary backgrounds or pictures. Don't distract the reader from the data.

Guidelines about Distortions

Avoid distortion. Never lie about the data.

Guidelines on Relative Graphs

Avoid relative graphs that do not contain data or scales.

Guidelines on 3-D

Avoid three dimensions. Three-dimensional charts may look nice, but they distract the reader and often lead to misinterpretation of the graphic.

The accompanying histogram represents the total tax collected by a federal tax collection service for fifty regions of varying sizes and populations in a certain country. Explain why the graph is misleading.

Different regions could have drastically different population sizes. The region with the largest population is going to pay a lot more in taxes than the region with the smallest population. Thus, the graph does not take into account the size and population of each region. The moral of the story here is that many variables should be considered on per capita​ (per person) basis.

Guidelines on Designs

Do not use more than one design in the same graphic. Sometimes graphs use a different design in one portion to draw attention to that area. Don't try to force the reader to a specific part of the graph. Let the data speak for themselves.

Guidelines for Titles

Include a meaningful ______ on the graph.

Guidelines on Intervals

Intervals should be the same; redistribute intervals to the same size

Guidelines for Axes

Label and name the _______ clearly, providing explanations if needed. Include units of measurement and a data source when appropriate.

Guidlines about space in graphs

Minimize the amount of white space in the graph. Use the available space to let the data stand out. If you truncate the scales, clearly indicate this to the reader.

Difference Between a misleading and a deceving graph

Misleading: a graph that unintentionally creates an incorrect impression Deceptive: a graph that pruposely creastes an incorrect impression

Guidelines on Sources

One final point to make. When reading graphs, look at the source of the data represented in the graphic. Often, a group with an agenda will conduct allegedly unbiased studies and report the results that support their position. Always "consider the source" and any possible hidden agendas they may have when reading graphics.

Guidelines on Bar Heights

The heights should be porportionate to the data; do not depict information that makes one category seem bigger than the other one by using an inconsistent scale

​(c) Explain how different measures may be used to support two completely different positions. Choose the correct answer below. A. The data collected can be changed so that it will support the position. B. The scales used in the graph can significantly affect the message.​ Also, the variable used to convey the message on the graph can make a large difference as well. C. Data can be rearranged on the graph to make the graph support any position. D. Values can be left out of the graph so that the graph supports the position.

The scales used in the graph can significantly affect the message.​ Also, the variable used to convey the message on the graph can make a large difference as well.

Guidelines on the Axes

They should begin at zero to avoid misleading the reading. if starting at another value is necessary, then include a graph break

Scale Break

This symbol lets the reader know tah the scale has a break aka a gap

Bar Graph; A reader cannot tell whether the graph ends at the top of the nipple on the baby bottle or at the end of the milk.

What graphic is being displayed? What is wrong with this graphic?

When using data that pertains to the number of people what should you use?

you should use percentages of the people who did something or belong to a certain group rather than the number

Pictograms

graphs that use picutres to represent the data

Why is using pcitures (ie soccerballs) in a graph misrepresentation?

if the dimenisons are not proportionate, it can be misleading. the dimensions of the picture should be proprotionate to the data.

Why is it emphasized that the bars aor classes should be the same width?

when comparing bars, our eyes actually compare the areas of the bars. THus, the emphasis on the ______. Unifromed _______ ensures that the area is proprotional to the height so taht we can simply compare the bar heights