Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Principal Components Analysis with count data


From   "Jason Ferris" <[email protected]>
To   <[email protected]>
Subject   st: Principal Components Analysis with count data
Date   Fri, 14 Aug 2009 09:08:48 +1000

Nick,
Thank you for your added comments; it gives me hope not to have to
categorise the data and use MCA methods.

To address your third point: 

3. Whether PCA will work well does depend on what you expect it to do
ideally, which is not clear in the question. 

We have a survey question of 2600 people.  Who answer 14 questions about
varying degrees of community harms.  Each question collects 'how many
times did this happen to you in the previous 12 months'.  So we collect
counts of all 14 questions - ranging from 0 to 365 (indicating at least
once a day).  The typical pattern for most of the items are as follows:
mean <2; 50 percentile (0); 75 percentile (0/1).  

We are hoping to reduce the 14 questions to 3/4 main components to use
as outcome variables for further analysis.

If we go down the MCA approach we would probably group the data 0, 1/5,
6+.

HTH,
Jase

------------------------------------------
DISCLAIMER: This message (including any attachments) is intended solely for the addressee(s) named and may contain confidential or privileged information. 
If you are not the intended recipient, please delete it and notify the sender. 
Views expressed in this message are those of the individual sender,and are not necessarily the views of the Turning Point Alcohol and Drug Centre Inc (ABN: 17 302 055 629).  

<a href="http://www.turningpoint.org.au";>Turning Point Alcohol and Drug Centre Inc</a>

Although this message and any attachments have been scanned for viruses by 'Trend Micro InterScan' at the time of sending, 
you are advised to rescan on receipt.

The whole or parts of this email may be subject to copyright of Turning Point Alcohol and Drug Centre Inc (ABN: 17 302 055 629), and/or third parties. 
You can only re-transmit, distribute or use the material if you are authorised to do so.

Please consider the environment before printing this email or attachments.

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index