regression, and missing data

[Gene Shackman]

Hi

I'm using the windows version, psppire.exe 0.7.8-g997322, that I downloaded from

http://www.gnu.org/software/pspp/get.html

I'm using windows vista, home version.

My question is about linear regression. If I use data that has no missing values, then PSPP regression seems to work fine. I compared the results with other packages and got the same results, see  http://gsociology.icaap.org/methods/comparing_freestaprograms.html

However, if I use data that does have missing values, I get results that are different from other programs. See the results from other programs here
http://gsociology.icaap.org/methods/comparing_freestaprograms_missing.html
this also lists the data set I'm using, and attached below are the results I get from PSPP  (If you format this as courier, it aligns up right.)

So 2 questions
1. How does pspp deal with missing? By the way, I tried coding blanks as missing and also tried replacing all the missing values with -99999 and told pspp those were missing values, and got exactly the same results.

2. There don't appear to be any options on how regression is done, like forward, backward, forced, etc. I didn't see anything in the documentation about it either. Is it just doing straight forced regression? Will there be any options on how to do regression?

Thanks very much.

REGRESSION
    /VARIABLES= c_arable climate North phone_kpop
    /DEPENDENT=     gini
    /STATISTICS=COEFF R ANOVA.

Model Summary
#====#========#=================#==========================#
#  R #R Square|Adjusted R Square|Std. Error of the Estimate#
##===#========#=================#==========================#
#|.60#     .36|              .35|                      8.65#
##===#========#=================#==========================#

ANOVA
#===========#==============#===#===========#=====#============#
#           #Sum of Squares| df|Mean Square|  F  |Significance#
##==========#==============#===#===========#=====#============#
#|Regression#       4548.35|  4|    1137.09|15.19|         .00#
#|Residual  #       7933.89|106|      74.85|     |            #
#|Total     #      12482.24|110|           |     |            #
##==========#==============#===#===========#=====#============#

Coefficients
#===========#=====#==========#====#=====#============#
#           #  B  |Std. Error|Beta|  t  |Significance#
##==========#=====#==========#====#=====#============#
#|(Constant)#47.95|      2.06| .00|23.22|         .00#
#| c_arable # -.12|       .05|-.20|-2.28|         .02#
#|  climate #-1.24|      1.04|-.11|-1.20|         .23#
#|   North  # -.14|       .03|-.43|-4.96|         .00#
#|phone_kpop#  .00|       .00|-.07| -.81|         .42#
##==========#=====#==========#====#=====#============#


 

Gene

Gene Shackman, Ph.D.
The Global Social Change Research Project
http://gsociology.icaap.org
Free Resources for Methods in Evaluation and Social Research
http://gsociology.icaap.org/methods
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Applied Sociologist
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