Misleading graphs and statistics
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

Misleading Graphs and Statistics PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on
  • Presentation posted in: General

Misleading Graphs and Statistics. MEAP REVIEW. Questions to Ask When Looking at Data and/or Graphs. Is the information presented correctly? Is the graph trying to influence you? Does the scale use a regular interval? What impression is the graph giving you?. Why is this graph misleading?.

Download Presentation

Misleading Graphs and Statistics

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Misleading graphs and statistics

Misleading Graphs and Statistics

MEAP REVIEW


Questions to ask when looking at data and or graphs

Questions to Ask When Looking at Data and/or Graphs

  • Is the information presented correctly?

  • Is the graph trying to influence you?

  • Does the scale use a regular interval?

  • What impression is the graph giving you?


Why is this graph misleading

Why is this graph misleading?

This title tells the reader what to think (that there are huge increases in price).

The scale moves from 0 to 80,000 in the same amount of space as 80,000 to 81,000.

The actual increase in price is 2,000 pounds, which is less than a 3% increase.

The graph shows the second bar as being 3 times the size of the first bar, which implies a 300% increase in price.


A more accurate graph

A more accurate graph:

An unbiased title

A scale with a regular interval.

This shows a more accurate picture of the increase.


Why is this graph misleading1

Why is this graph misleading?

The scale does not have a regular interval.


Graphs can be misleading in the news

Graphs can be misleading in the news.

  • The margin of error is the amount (usually in percentage points) that the results can be “off by.”

  • Be wary of data with large margins of error.


From cnn com

From CNN.com


Problems

Problems:

  • The difference in percentage points between Democrats and Republicans (and between Democrats and Independents) is 8% (62 – 54). Since the margin of error is 7%, it is likely that there is even less of a difference.

  • The graph implies that the Democrats were 8 times more likely to agree with the decision. In truth, they were only slightly more likely to agree with the decision.

  • The graph does not accurately demonstrate that a majority of all groups interviewed agreed with the decision.


Cnn com updates the graph

CNN.com updates the graph:


Misleading graphs and statistics

What does the top of this graph show?

  • About 12 million people are downloading music legally.

  • Just over 9 million people are downloading music illegally.

The bottom of the graph is misleading. Why?

  • The graph implies that 1% of the iPods are filled with legally downloaded music.

  • It implies that the other 99% are filled with illegally downloaded music.

Why is this wrong?


What could be in those ipods besides legally downloaded music

What could be in those iPods besides legally downloaded music?

  • Empty space – most people don’t have iPods that are filled to capacity.

  • Songs that were added from legally purchased CDs.

  • Games, calendars, other applications.

  • Songs that were downloaded illegally.

It is possible that the rest of the iPod contains some illegally downloaded music, but it is unlikely that 99% of a person’s iPod is filled with illegal music.


More information

More information:

  • The iPod graphic appeared in Wired magazine.

  • A quote from the article: “What’s filling all that excess capacity? Well, despite the efforts of the Recording Industry Association of America, nearly a billion songs are traded on P2P networks every month.”

  • This article was trying to imply that all of the excess space is filled with illegal downloads, which is likely untrue.

  • The statistics for the article were provided by the music industry.


Homework time

Homework Time


  • Login