Loading in 5 sec....

Interpreting ScatterplotsPowerPoint Presentation

Interpreting Scatterplots

- By
**liam** - Follow User

- 589 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about 'Interpreting Scatterplots' - liam

**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

### Interpreting Scatterplots

Presentation 2.3

Scatterplots

- When looking at scatterplots, we will look for:
- Association (or direction)
- Form
- Strength
- Outliers

Direction

A trend that runs from the upper left to the lower right is said to have a negative association or direction.

A trend running the from the lower left to upper right has a positive association or direction.

It is a lot like slope!

Direction

- It is possible for a scatterplot to have no association or direction.
- This occurs when the plot looks like a random splattering of dots.

Form

- Form:
- If there is a straight line (linear) relationship, it will appear as a cloud or swarm of points stretched out in a generally consistent, straight form.
- If the relationship isn’t straight, but curves, while still increasing or decreasing steadily, we can often find ways to make it more nearly straight.

Strength

- Strength:
- At one extreme, the points appear to follow a single stream (whether straight, curved, or bending all over the place).
- At the other extreme, the points appear as a vague cloud with no discernable trend or pattern.

- Note: we will quantify the strength soon (that’s the r).

Outliers

- Outliers:
- As before, points that do not follow the pattern.
- Outliers may be in either the x-direction, y-direction, or both directions.
- There’s no better example than the 2000 presidential election.

Outliers

- 2000 Presidential Election
- Remember Florida
- The scatterplot on the next page details the number of votes for Bush and the number of votes for Buchanon.
- As you would expect, the more people voting for Bush should mean more people voting for Buchanon (since there are simply more people voting).
- In Palm Beach County there was much confusion about the ballot.
- The Democratic Party alleged that the ballot was poorly designed thus skewing the vote.
- The scatterplot shows the evidence.

2000 Presidential Election

- Apparently in Palm Beach County only, a disproportionate number of people voted for Buchanon.
- This point is a great example of an outlier.
- The outlier is in the y-direction (vertical).

- This point is a great example of an outlier.
- Why did this happen?
- The next slide shows the ballot voters used.

Scatterplots

- Remember, when looking at scatterplots, look for:
- Association (or direction)
- Form
- Strength
- Outliers

Scatterplots

- This concludes this presentation.

Download Presentation

Connecting to Server..