Does anyone know why SPSS excludes certain variables from a regression? Also, does anyone know how to prevent this from happening?
Thanks, Miljan 
One reason SPSS will exclude variables from a regression is if they are
not numeric. For example, a gender variable that uses M and F to represent male and female would have to be recoded as 0 and 1 to be used in a regression. ____________________________________ Justin Meyer Rowland Reading Foundation phone: 8663707323 fax: 6082043846 ____________________________________ Original Message From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of mmarkus Sent: Friday, January 18, 2008 2:40 PM To: [hidden email] Subject: Excluded variables from regression Does anyone know why SPSS excludes certain variables from a regression? Also, does anyone know how to prevent this from happening? Thanks, Miljan  View this message in context: http://www.nabble.com/Excludedvariablesfromregressiontp14957806p1495 7806.html Sent from the SPSSX Discussion mailing list archive at Nabble.com. ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
Another possibility is that you have inadvertantly chosen the "stepwise"
method of variable selection. On Jan 18, 2008 4:45 PM, Justin Meyer <[hidden email]> wrote: > One reason SPSS will exclude variables from a regression is if they are > not numeric. For example, a gender variable that uses M and F to > represent male and female would have to be recoded as 0 and 1 to be used > in a regression. > > ____________________________________ > > Justin Meyer > > Rowland Reading Foundation > > phone: 8663707323 fax: 6082043846 > > ____________________________________ > > > Original Message > From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of > mmarkus > Sent: Friday, January 18, 2008 2:40 PM > To: [hidden email] > Subject: Excluded variables from regression > > Does anyone know why SPSS excludes certain variables from a regression? > Also, > does anyone know how to prevent this from happening? > > Thanks, > > Miljan >  > View this message in context: > http://www.nabble.com/Excludedvariablesfromregressiontp14957806p1495 > 7806.html > Sent from the SPSSX Discussion mailing list archive at Nabble.com<http://nabble.com/> > . > > ===================== > To manage your subscription to SPSSXL, send a message to > [hidden email] (not to SPSSXL), with no body text except the > command. To leave the list, send the command > SIGNOFF SPSSXL > For a list of commands to manage subscriptions, send the command > INFO REFCARD > > ===================== > To manage your subscription to SPSSXL, send a message to > [hidden email] (not to SPSSXL), with no body text except the > command. To leave the list, send the command > SIGNOFF SPSSXL > For a list of commands to manage subscriptions, send the command > INFO REFCARD > ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
If ENTER method is used; that is, if all the
predictors variables (X's) are forced to ENTER in the regression model, exclusion will possibly occur especially if some of the X's are highly correlated (multicollineary problem). Basically, if a set of predictor variables are highly correlated only one is included in the regression model and the rest are excluded. Why not use SEM, instead of regression? Johnny  "James C. Whanger" <[hidden email]> wrote: > Another possibility is that you have inadvertantly > chosen the "stepwise" > method of variable selection. > > > > On Jan 18, 2008 4:45 PM, Justin Meyer > <[hidden email]> > wrote: > > > One reason SPSS will exclude variables from a > regression is if they are > > not numeric. For example, a gender variable that > uses M and F to > > represent male and female would have to be recoded > as 0 and 1 to be used > > in a regression. > > > > ____________________________________ > > > > Justin Meyer > > > > Rowland Reading Foundation > > > > phone: 8663707323 fax: 6082043846 > > > > ____________________________________ > > > > > > Original Message > > From: SPSSX(r) Discussion > [mailto:[hidden email]] On Behalf Of > > mmarkus > > Sent: Friday, January 18, 2008 2:40 PM > > To: [hidden email] > > Subject: Excluded variables from regression > > > > Does anyone know why SPSS excludes certain > variables from a regression? > > Also, > > does anyone know how to prevent this from > happening? > > > > Thanks, > > > > Miljan > >  > > View this message in context: > > > > > 7806.html > > Sent from the SPSSX Discussion mailing list > archive at Nabble.com<http://nabble.com/> > > . > > > > ===================== > > To manage your subscription to SPSSXL, send a > message to > > [hidden email] (not to SPSSXL), with > no body text except the > > command. To leave the list, send the command > > SIGNOFF SPSSXL > > For a list of commands to manage subscriptions, > send the command > > INFO REFCARD > > > > ===================== > > To manage your subscription to SPSSXL, send a > message to > > [hidden email] (not to SPSSXL), with > no body text except the > > command. To leave the list, send the command > > SIGNOFF SPSSXL > > For a list of commands to manage subscriptions, > send the command > > INFO REFCARD > > > > ===================== > To manage your subscription to SPSSXL, send a > message to > [hidden email] (not to SPSSXL), with no > body text except the > command. To leave the list, send the command > SIGNOFF SPSSXL > For a list of commands to manage subscriptions, send > the command > INFO REFCARD > ____________________________________________________________________________________ Be a better friend, newshound, and knowitall with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
In reply to this post by mmarkus
This question was asked last year...
Does anyone know why SPSS excludes certain variables from a regression? Also, does anyone know how to prevent this from happening? There were various offers of help/suggestions: that the variables excluded were not numeric That stepwise had been used instead of 'enter' That there was multicollinearity I've checked my variables and they contain numeric values, I'm using 'enter' and the tolerance levels are at least .4 or above. The background: I'm using hierarchical multiple regression to check for interaction between a qualitative continuous predictor variable and group membership. The continuous predictor variable and dummy variables to denote group (coded 0 for not in group, 1 for in group) go in block one, along with some covariate continuous predictor variables. Then each of the six dummy variables is linked with one of the continuous predictor variables to create six product terms and these go in block two. (For clarity, I'm leaving one group out of the first block and this will be represented by the constant, but putting all six product terms in block two) Although SPSS 16 is producing a coefficient table with the sort of results I'm looking for, it's also producing a second table underneath labelled 'excluded variables' and in this table is all of the product terms (a centred numeric figure with + or  value x a dummy code of 1). I'm thinking I can't ignore this table and that it has excluded the variables for a reason to do with coding?  View this message in context: http://old.nabble.com/Excludedvariablesfromregressiontp14957806p27061302.html Sent from the SPSSX Discussion mailing list archive at Nabble.com. ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
In reply to this post by mmarkus
Possible reason for exclusion could be speed of processing
Spss on desktop is slower than say sas for regression BUT things could be different on grid computers Does anyone know spss licensing on deploying it on amazon or any other cloud computer with multiple processors Regards Ajay http:\\decisionstats.com Sent from my iPhone On Jan 7, 2010, at 6:59 AM, CarolineUK <[hidden email]> wrote: > This question was asked last year... > > Does anyone know why SPSS excludes certain variables from a > regression? > Also, does anyone know how to prevent this from happening? > > There were various offers of help/suggestions: > that the variables excluded were not numeric > That stepwise had been used instead of 'enter' > That there was multicollinearity > > I've checked my variables and they contain numeric values, I'm using > 'enter' > and the tolerance levels are at least .4 or above. > > The background: I'm using hierarchical multiple regression to check > for > interaction between a qualitative continuous predictor variable and > group > membership. The continuous predictor variable and dummy variables > to denote > group (coded 0 for not in group, 1 for in group) go in block one, > along with > some covariate continuous predictor variables. Then each of the six > dummy > variables is linked with one of the continuous predictor variables > to create > six product terms and these go in block two. > > (For clarity, I'm leaving one group out of the first block and this > will be > represented by the constant, but putting all six product terms in > block two) > > Although SPSS 16 is producing a coefficient table with the sort of > results > I'm looking for, it's also producing a second table underneath > labelled > 'excluded variables' and in this table is all of the product terms (a > centred numeric figure with + or  value x a dummy code of 1). > I'm thinking I can't ignore this table and that it has excluded the > variables for a reason to do with coding? >  > View this message in context: http://old.nabble.com/Excludedvariablesfromregressiontp14957806p27061302.html > Sent from the SPSSX Discussion mailing list archive at Nabble.com. > > ===================== > To manage your subscription to SPSSXL, send a message to > [hidden email] (not to SPSSXL), with no body text except > the > command. To leave the list, send the command > SIGNOFF SPSSXL > For a list of commands to manage subscriptions, send the command > INFO REFCARD ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
Please. Speed of processing has nothing to do with variable exclusion. Most likely the product terms are highly collinear or constant. HTH, Jon Peck SPSS, an IBM Company [hidden email] 3126513435
Possible reason for exclusion could be speed of processing Spss on desktop is slower than say sas for regression BUT things could be different on grid computers Does anyone know spss licensing on deploying it on amazon or any other cloud computer with multiple processors Regards Ajay http:\\decisionstats.com Sent from my iPhone On Jan 7, 2010, at 6:59 AM, CarolineUK <[hidden email]> wrote: > This question was asked last year... > > Does anyone know why SPSS excludes certain variables from a > regression? > Also, does anyone know how to prevent this from happening? > > There were various offers of help/suggestions: > that the variables excluded were not numeric > That stepwise had been used instead of 'enter' > That there was multicollinearity > > I've checked my variables and they contain numeric values, I'm using > 'enter' > and the tolerance levels are at least .4 or above. > > The background: I'm using hierarchical multiple regression to check > for > interaction between a qualitative continuous predictor variable and > group > membership. The continuous predictor variable and dummy variables > to denote > group (coded 0 for not in group, 1 for in group) go in block one, > along with > some covariate continuous predictor variables. Then each of the six > dummy > variables is linked with one of the continuous predictor variables > to create > six product terms and these go in block two. > > (For clarity, I'm leaving one group out of the first block and this > will be > represented by the constant, but putting all six product terms in > block two) > > Although SPSS 16 is producing a coefficient table with the sort of > results > I'm looking for, it's also producing a second table underneath > labelled > 'excluded variables' and in this table is all of the product terms (a > centred numeric figure with + or  value x a dummy code of 1). > I'm thinking I can't ignore this table and that it has excluded the > variables for a reason to do with coding? >  > View this message in context: http://old.nabble.com/Excludedvariablesfromregressiontp14957806p27061302.html > Sent from the SPSSX Discussion mailing list archive at Nabble.com. > > ===================== > To manage your subscription to SPSSXL, send a message to > [hidden email] (not to SPSSXL), with no body text except > the > command. To leave the list, send the command > SIGNOFF SPSSXL > For a list of commands to manage subscriptions, send the command > INFO REFCARD ===================== To manage your subscription to SPSSXL, send a message to [hidden email] (not to SPSSXL), with no body text except the command. To leave the list, send the command SIGNOFF SPSSXL For a list of commands to manage subscriptions, send the command INFO REFCARD 
What about Part 2
SPSS on cloud computing? Ajay
Websites http://decisionstats.com http://dudeofdata.com Linkedin www.linkedin.com/in/ajayohri On Thu, Jan 7, 2010 at 8:38 AM, Jon K Peck <[hidden email]> wrote:

Administrator

In reply to this post by CarolineUK
 snip  If I follow, there are 6 groups that are coded with 5 indicator variables in block 1. If that is correct, then the interaction of that GROUP variable with the continuous variable needs to be represented by 5 product terms, not 6. The 5 product terms are the same 5 indicator variables you have in block 1 multiplied by the continuous variable.

Bruce Weaver bweaver@lakeheadu.ca http://sites.google.com/a/lakeheadu.ca/bweaver/ "When all else fails, RTFM." NOTE: My Hotmail account is not monitored regularly. To send me an email, please use the address shown above. 
You've summed up perfectly Bruce  so as well as leaving out the 'reference group' for the group analysis, I need to leave out the product term which is part made up of that same group? If so, how do I know how to calculate whether the product term I've left out is significant? (because you only get one 'constant' line, and that's for the group dummy variable, not the product term derivative of it?)
Cheers in confusion...

Free forum by Nabble  Edit this page 