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One Proportion Test

by on Jul.21, 2010 , under JMP & JSL

One Proportion Test is a JMP script for performing a One Proportion Test quickly and easily.

Background

This script is inspired by a recent question on the LinkedIn Group “JMP Professional Network” from Jennifer Atlas, Senior Business Development Coordinator at Minitab, who asked:

I know I can calculate a sample size for a one proportion test in JMP, but how do I test for 1 proportion?

Karen Copeland, Ph.D., from Boulder Statistics promptly gave a helpful explanation of how to do it in JMP. JMP handles the problem quite capably, but you have to know where to find it and remember a bunch of details about how to use it:

To test one proportion in JMP I use the distribution platform. When you run a distribution for a nominal variable then in the red drop down menu there is an option for testing probabilities.

Details:

If you have a data table with a column for your proportion then you can proceed straight to the distribution platform. If not then first create a summary table with two columns. The first column would be your outcome such as Y/N or 0/1 and the he second column would be your frequency column of how many of each outcome you observed.

Testing of a proportion:

1. With a column of outcomes: First make sure that your column is of the nominal type. Second, use the distribution platform to create a distribution of the outcome. Under the red triangle drop down menu select “Test Probabilities” and a dialog box will appear with various options for testing your probabilities. Note, you need only fill in the one probability that you are interested in testing.

2. With a summary table for your outcomes: Again, make sure that your outcome column is of the nominal type. Second, use the distribution platform with your outcome column as the Y and the frequency column as the “Freq”. Then continue as above by selecting the test probabilities from the red triangle menu.

Note that you will also find confidence intervals for your proportions in the red drop down menu.

Boulder Statistics LLC and Global Pragmatica LLC are strategic allies, pairing Boulder Statistics’ analytical expertise with Global Pragmatica’s JMP scripting expertise to deliver outstanding solutions to our clients. When I saw Karen’s explanation, I immediately thought this would be a great opportunity to collaborate with her and build a JSL widget to make this easier.

This script is the result, and Global Pragmatica and Boulder Statistics are proud to make it available free, in an encrypted (run-only) script you can download today.

How to use One Proportion Test

You must license or download a demo copy of JMP software from SAS to use this JMP add-on script.

Launch the script. You are asked to choose a data table, which can be set up either of the two ways Dr. Copeland describes above. A dialog box requests the necessary column assignments. Click OK. At the bottom, fill in the details of the One Proportion Test. Use the Start Over button to restart the analysis with a different data table. For further help, see text at the top of the window and tooltips when hovering over buttons.

How encrypted scripts work (the free widget)

Encrypted scripts are run-only scripts. They are not human-readable, so you can’t modify them or adapt them for other purposes. If you would like to study the JSL, modify, or adapt the script, you should license the unencrypted version of this script instead.

Why pay for the unencrypted script?

Don’t! At least not right away… Start by “buying” the free widget. Try it out and see if you like it!

If you do, you might want to buy the full-price unencrypted script, so that you can modify, customize, or adapt the script for your own specialized needs, or so you can study a professional-quality script! This script demonstrates quite a few advanced scripting techniques, including:

  • building an elegant, all-in-one-window user interface using display objects
  • attaching scripts to buttons, radio buttons, column lists, etc.
  • including a custom logo graphic
  • implementing a different dialog box according to the user’s radio button choice
  • opening, closing, and deleting display tree elements dynamically
  • offering tips and help right in the window
  • including email and web links for more information, sending feedback, etc.
  • hiding globals—whether to protect intellectual property or to avoid cluttering up Show Globals() output
  • optimizing memory management and simplifying between-use value-clearing by storing problem-specific “globals” as entries in an Associative Array() instead of in globals

You can read more about encrypted vs. unencrypted scripts offered by Global Pragmatica here.

Compatibility

One Proportion Test has been tested on JMP 8 for Mac and Windows as well as current beta versions of JMP 9 for Mac and Windows.

Known issues

  • In the second (no longer current) early adopter release of JMP 9 for Windows, you have to start the script manually. (This is not a problem in JMP 8 or later beta releases of JMP 9.) There are several ways to do this:
    • press Ctrl-R, or
    • click the Run Script button in the toolbar, or
    • from the Edit menu, select Run Script

Buy now!

Contact me if you’re interested in purchasing this script or commissioning one like it.

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