Marketing - MaxDiff - Analyze with Ranking Question (Legacy) - Preference Share Variables from Individual-Level Parameter Means (All Alternatives)

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This QScript computes preference shares for the alternatives in a MaxDiff experiment using individual-level parameter means.

Example

This example uses the data from the MaxDiff Case Study. The table on the left shows a SUMMARY of Individual-Level Parameter Means generated using Q's Segments tool. The table on the right shows a SUMMARY of the preference shares generated by this QScript.

MaxDiffPrefShares1.PNG

Technical details

Input data

This QScript uses data from individual-level parameter means from a MaxDiff experiment. The variables should be combined into a Number - Multi question that has the string Individual-Level Parameter Means in the name. The individual-level parameters question can be generated in Q from a segmentation of a ranking question (by right-clicking a node of the tree and selecting Save Individual-Level Parameter Means and Standard Deviations).

Alternatively, the individual-level parameter means can be computed externally and imported into Q as part of a larger data set. In this case:

Outputs

A new Number - Multi question is generated in the project, and a table is added to the report to show the average of the computed values.

Further reading: MaxDiff software

Logit transformation

The formula used to obtain the share for alternative [math]\displaystyle{ j }[/math] of an attribute is:

[math]\displaystyle{ S_{j} = \frac{e^{\beta_{j}}}{\sum_{j'}e^{\beta_{j'}}} }[/math],

where the sum ranges over all of the alternatives, and [math]\displaystyle{ \beta_{j} }[/math] is the individual-level parameter mean for alternatives [math]\displaystyle{ j }[/math].

How to apply this QScript

  • Start typing the name of the QScript into the Search features and data box in the top right of the Q window.
  • Click on the QScript when it appears in the QScripts and Rules section of the search results.

OR

  • Select Automate > Browse Online Library.
  • Select this QScript from the list.

Customizing the QScript

This QScript is written in JavaScript and can be customized by copying and modifying the JavaScript.

Customizing QScripts in Q4.11 and more recent versions

  • Start typing the name of the QScript into the Search features and data box in the top right of the Q window.
  • Hover your mouse over the QScript when it appears in the QScripts and Rules section of the search results.
  • Press Edit a Copy (bottom-left corner of the preview).
  • Modify the JavaScript (see QScripts for more detail on this).
  • Either:
    • Run the QScript, by pressing the blue triangle button.
    • Save the QScript and run it at a later time, using Automate > Run QScript (Macro) from File.

Customizing QScripts in older versions

  • Copy the JavaScript shown on this page.
  • Create a new text file, giving it a file extension of .QScript. See here for more information about how to do this.
  • Modify the JavaScript (see QScripts for more detail on this).
  • Run the file using Automate > Run QScript (Macro) from File.

JavaScript

includeWeb("QScript Functions to Generate Outputs");
includeWeb("QScript Functions for Setting Up Experiments");
var type = "Preference Shares";
if (!maxDiffUtilityCalculation(type))
    log("QScript Cancelled");
else
    conditionallyEmptyLog("QScript Finished");

See also