Reusable Topic Elements

Dataset Sources

Most SALT analyses require a dataset. SALT datasets are provided in one of three ways:

• Existing datasets
• Uploaded datasets
• Datasets provided by WebAssign questions

Each dataset is a table of values for selected variables.

Variable Types

Variables can be one of two types:

Categorical

Qualitative values that are used to organize or categorize data.

Examples include diagnostic codes, dates, or names of things or people.

Numerical

Quantitative values that are used as the basis for numerical analyses.

Examples include measurements, prices, or counts of things.

1. Save the filtered dataset.

   1. Click Download Dataset.

   2. Select the format to save.

   3. Click Download.

   4. Select where to save the dataset.

   After saving, you might need to click ╳ to close the Download panel.

2. Select up to twenty variables to use in your analysis.

3. If needed, click Numerical › Categorical beside a quantitative variable to treat it as a categorical variable.

4. Click Select.

   The selected data are shown in the Preview Table.

5. To expand a table, click at the top of the table.

6. Click the Gradebook tab.

7. Under Settings, set Variable 1 to the variable for which you want to generate samples.

8. If you selected a variable, set Level of Variable 1 to the value of interest.

9. Set the Number of Samples to generate.

10. Click Generate Samples.

    A dot plot displays the sampling distribution of each generated sample's statistic.

    Below the dot plot, either a summary table or graph displays statistics for both the original dataset and the currently selected sample.

11. If needed, click Generate Samples again to add more samples.

    • To start again, click Reset.
    • To clear a variable, click ╳ beside it.

12. To select a sample, click its dot in the dot plot.

    The sample comparison data below the dot plot is updated.

13. Adjust the Proportion, α, and Critical Values.

    • Use the Proportion slider.
    • Enter the Critical Value—or both values if you are coloring both tails.

    The Proportion, α, and Critical Values and shading of the dot plot are updated.

14. Select which tail to color in the dot plot.

    • Color Left Tail
    • Color Right Tail
    • Color Both Tails

15. If you selected a variable:

    1. Set Level of Variable 1 to the value of interest.

    2. Set Test Parameter to either Proportion or Count.

    3. Set the Null Value to use.

16. If you selected a variable:

    1. Set Variable 2 to a second variable.

    2. Set Test Parameter to either Slope or Correlation.

If needed, click ╳ beside a variable to clear it.