Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


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

st: Repeated Measures ANOVA and Missing Values


From   "John L. Woodard, Ph.D." <[email protected]>
To   [email protected]
Subject   st: Repeated Measures ANOVA and Missing Values
Date   Sun, 16 Oct 2011 16:15:29 -0400

I'm trying to run a oneway repeated measures ANOVA (the variable is =
session, with three levels).  I have organized my data in long format, =
with one column for subject ID, one column for session number and one =
column for the dependent variable.  Here is a listing of part of my data =
file:

	ID	 session   DV
211. | 245         1      139 |
212. | 245         2      141 |
213. | 245         3        . |
214. | 247         1      137 |
215. | 247         2        . |
    |------------------------|
216. | 247         3        . |
217. | 249         1      138 |
218. | 249         2      141 |
219. | 249         3      144 |
220. | 250         1      141 |
    |------------------------|
221. | 250         2      135 |
222. | 250         3        . |
223. | 251         1      142 |
224. | 251         2      139 |
225. | 251         3      143 |


There are obviously several cases that are missing observations at =
session 2 or session 3.  Does wsanova or Stata's anova command =
automatically drop cases with missing values at any of the three =
sessions?  My first pass with the analysis seems to suggest it does not.

What is the best way to deal with these missing values (either deleting =
cases with missing values or telling wsanova or anova to ignore them in =
the analysis)?  Many thanks in advance!

John
John L. Woodard, Ph.D.
Associate Professor of Psychology
Wayne State University
5057 Woodward Ave., 7th Floor
Detroit, MI  48202

(313) 577-5838 (voice)
(313) 577-7636 (fax)
john.woodard@@wayne.edu




*
*   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 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index