Unequal no of factor variables

[Rhonda Boorman-2]

This is a conceptual issue, not technical.  I'm hoping I can get some opinions.

With data (n = 320) gathered from a survey we are developing to assess organisational attitudes (scale of 1-5), I ran a factor analysis and found 4 factors made up of unequal numbers of variables, dropping from 10 variables in factor one, to 6 in factor two, to 4, to 2.  The content of the factors was meaningful.

Another survey was also completed at the same time, and I hoped to use this for concurrent validity.  However, the correlations are all highest (r = .4) with factor one, followed by factor two etc.

Can I assume that this is an attribute of the unequal number of variables in the factors, with the larger factors having greater distribution and less variance and thus are more likely to have a higher effect size?

With respect to listers who are so generous with their extensive SPSS knowledge, if research questions of this nature are better raised in an alternative forum, just let me know, and where it is.

Kind Regards

Rhonda

====================To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Deydre Teyhen]

> Ladies and Gentlemen:

I have hopefully what is a quick question.  I have a nested design in
which companies 1 through 5 belong to organization A and 6-10 belong
to organization B....and then A and B belong to organization Z (and so
on).  Bottom-line - 3 layers of nesting.

Each company's data is represented as a row of data in SPSS.  But, I
what I would like to be able to do is have a row to represent
organizations A through E and rows to represent organizations T
through Z.

In excel - you could easily have the sum of rows 1 through 5 be
entered into the row designated for organization A, the sum of rows
6-10 into the row designated for organization B, etc.

However, I only know how to add/calculate columns in SPSS and not new
additional rows.

If anyone has any ideas - it would be greatly appreciated.

Kindest Regards,
Deydre Teyhen
Associate Professor
US Army-Baylor University

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Hector Maletta]

Rhonda,
You had apparently 320 cases with 22 variables in your first study (number
of cases and variables not reported for the second study). These figures
represent quite a low number of cases per variable, which translates into
large sampling error. Even if the second study is a perfect replication of
the first, taken almost at the same time (i.e. without any external
condition having varied), you may expect perceptible variation from one
sample to the next. If other conditions also varied between the two studies
(number of cases and variables, details about methodology, interview
technique, etc) the differences may be still larger. If some time elapsed
between the two, some conditions may have also changed, making subjects
respond differently.
All in all, one may expect that the two studies yield significant
differences in the correlation of variables, and more so in factor structure
when these are based on a different array of variables.
It is worth repeating here that "factors" or "components" emerging from
factor analysis are only statistical constructs, mere algebraic derivations
of regression and correlation coefficients, and cannot be construed as real
"objects". Only for studies that are perfect replications of one another,
with variables that are very stable over time and across subjects, and with
samples large enough to ensure narrow margins of sampling error, you may
expect that the overall factor structure is more or less the same in both
studies. Otherwise, I would be rather surprised to find them equal.

Hector



-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
Rhonda Boorman
Sent: 29 April 2008 21:33
To: [hidden email]
Subject: Unequal no of factor variables

This is a conceptual issue, not technical.  I'm hoping I can get some
opinions.

With data (n = 320) gathered from a survey we are developing to assess
organisational attitudes (scale of 1-5), I ran a factor analysis and found 4
factors made up of unequal numbers of variables, dropping from 10 variables
in factor one, to 6 in factor two, to 4, to 2.  The content of the factors
was meaningful.

Another survey was also completed at the same time, and I hoped to use this
for concurrent validity.  However, the correlations are all highest (r = .4)
with factor one, followed by factor two etc.

Can I assume that this is an attribute of the unequal number of variables in
the factors, with the larger factors having greater distribution and less
variance and thus are more likely to have a higher effect size?

With respect to listers who are so generous with their extensive SPSS
knowledge, if research questions of this nature are better raised in an
alternative forum, just let me know, and where it is.

Kind Regards

Rhonda


To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Jerabek Jindrich]

Hello,

Try the AGGREGATE command (MENU/DATA/AGGREGATE), it can split your data into groups by the break variable and compute sums of the groups.
Something like this (NOT TESTED) could work:
AGGREGATE
  /OUTFILE=*
  /BREAK=organization
  /company_sum = SUM(company).

Warning - replaces current dataset, save your work before runing aggregate.


regards
Jindra

> ------------ Původní zpráva ------------
> Od: Deydre Teyhen <[hidden email]>
> Předmět: Nested Designs - SPSS
> Datum: 30.4.2008 02:45:07
> ----------------------------------------
> > Ladies and Gentlemen:
>
> I have hopefully what is a quick question.  I have a nested design in
> which companies 1 through 5 belong to organization A and 6-10 belong
> to organization B....and then A and B belong to organization Z (and so
> on).  Bottom-line - 3 layers of nesting.
>
> Each company's data is represented as a row of data in SPSS.  But, I
> what I would like to be able to do is have a row to represent
> organizations A through E and rows to represent organizations T
> through Z.
>
> In excel - you could easily have the sum of rows 1 through 5 be
> entered into the row designated for organization A, the sum of rows
> 6-10 into the row designated for organization B, etc.
>
> However, I only know how to add/calculate columns in SPSS and not new
> additional rows.
>
> If anyone has any ideas - it would be greatly appreciated.
>
> Kindest Regards,
> Deydre Teyhen
> Associate Professor
> US Army-Baylor University
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> [hidden email] (not to SPSSX-L), with no body text except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the command
> INFO REFCARD
>
>
>

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Melissa Ives]

If you use outfile=* mode=addvariables your current dataset will be retained with the additional variables calculated for each row.

The difference between adding aggregate variables and what you wanted is that the former does not insert new rows, but adds the value of the variable to each current row.
So all of companies 1-5 would get the same summary variable(s) for their organization A.

If you want to add rows, you could specify a file name as the outfile when you aggregate.  Then use add files to combine the company data (the original file) with the organization data (the new outfile from the AGGREGATE command) .  Although, I'm not sure what help this would be in terms of analysis as the variable would now include parts and the sum of the parts, effectively doubling the value--be careful.  If you really do want the organization and company variables to have the same name, then you would need to makee sure that the aggregate functions did not rename the variables. (e.g. /company=sum(company) instead of the example below).

Melissa

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Jerabek Jindrich
Sent: Wednesday, April 30, 2008 2:21 AM
To: [hidden email]
Subject: [SPSSX-L] Re:Nested Designs - SPSS

Hello,

Try the AGGREGATE command (MENU/DATA/AGGREGATE), it can split your data into groups by the break variable and compute sums of the groups.
Something like this (NOT TESTED) could work:
AGGREGATE
  /OUTFILE=*
  /BREAK=organization
  /company_sum = SUM(company).

Warning - replaces current dataset, save your work before runing aggregate.


regards
Jindra

> ------------ Původní zpráva ------------
> Od: Deydre Teyhen <[hidden email]>
> Předmět: Nested Designs - SPSS
> Datum: 30.4.2008 02:45:07
> ----------------------------------------
> > Ladies and Gentlemen:
>
> I have hopefully what is a quick question.  I have a nested design in
> which companies 1 through 5 belong to organization A and 6-10 belong
> to organization B....and then A and B belong to organization Z (and so
> on).  Bottom-line - 3 layers of nesting.
>
> Each company's data is represented as a row of data in SPSS.  But, I
> what I would like to be able to do is have a row to represent
> organizations A through E and rows to represent organizations T
> through Z.
>
> In excel - you could easily have the sum of rows 1 through 5 be
> entered into the row designated for organization A, the sum of rows
> 6-10 into the row designated for organization B, etc.
>
> However, I only know how to add/calculate columns in SPSS and not new
> additional rows.
>
> If anyone has any ideas - it would be greatly appreciated.
>
> Kindest Regards,
> Deydre Teyhen
> Associate Professor
> US Army-Baylor University
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> [hidden email] (not to SPSSX-L), with no body text except
> the command. To leave the list, send the command SIGNOFF SPSSX-L For a
> list of commands to manage subscriptions, send the command INFO
> REFCARD
>
>
>

=====================
To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD

PRIVILEGED AND CONFIDENTIAL INFORMATION
This transmittal and any attachments may contain PRIVILEGED AND
CONFIDENTIAL information and is intended only for the use of the
addressee. If you are not the designated recipient, or an employee
or agent authorized to deliver such transmittals to the designated
recipient, you are hereby notified that any dissemination,
copying or publication of this transmittal is strictly prohibited. If
you have received this transmittal in error, please notify us
immediately by replying to the sender and delete this copy from your
system. You may also call us at [phone] for assistance.

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD