"John Uebersax" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> The common factor model is compatible with the idea that you have
> unobserved constructs that you wish to estimate using item responses.
> The constructs are presumed measured with error. A commo
"Rich Ulrich" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> Ah... I notice, orthogonal factors can do a serious job of
> "reflecting the reality" of factors that are moderately correlated.
> If two axes are 70-degrees instead of 90-degrees, there's
> a mass
On 26 Jul 2001 09:29:52 -0700, [EMAIL PROTECTED] (Lise DeShea) wrote:
[ snip, previous]
> PCA explains variance. FA explains covariance.
If 'variance' of a variable is to be 1.0 using PCA, it is
(approximately) the multiple correlation using FA.
FA is not trying to fit the Unique variance
[EMAIL PROTECTED] (Eric Bohlman) wrote in message
news:<9jo444$jph$[EMAIL PROTECTED]>...
Thank you for mentioning this. This is a problem for statisticians
generally, not just those who work with Likert-type or similar items.
A very important example concerns drug response in pharmaceutical
cl
The common factor model is compatible with the idea that you have
unobserved constructs that you wish to estimate using item responses.
The constructs are presumed measured with error. A common factor
model takes this error into account, whereas PCA does not.
When we're talking about multiple p
Magenta wrote:
> Why a factor analysis and not a principal components analysis? I've been
> taught that a principal components analysis makes fewer assumptions on the
> data, so
> assuming that one can perform a factor analysis then automatically one can
> also perform a principal components ana
Rich Ulrich is correct that a dichotomy is interval, at least as far as
what arithmetic it is permissible to perform on it.
It is not so clear that it is interval in terms of what operations are
NOT trivial to perform on it. If I have numerically-coded ordinal data
I may recode using th
On 25 Jul 2001 12:33:49 -0700, [EMAIL PROTECTED] (Dennis Roberts) wrote:
> inherent problems related to LICKert items and level of measurement that
> create problems would be these too
>
> 1. how many response categories are there for AN item??? by the way ...
> likert used many types ... incl
>
>1) Responses in the middle of the scale represent something
>*qualitatively* different from responses near the ends. For example, if a
>particular issue isn't relevant or applicable to some of the
>subjects, they're likely to respond in the middle, but this doesn't mean
>the same thing as som
Magenta wrote:
>
> "Robert J. MacG. Dawson" <[EMAIL PROTECTED]> wrote in message
> [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Can you do factor ananlysis, then? Probably yes.
...
>
> Why a factor analysis and not a principal components analysis?
Dunno. But the interesting part of t
"Robert J. MacG. Dawson" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> Can you do factor ananlysis, then? Probably yes. If the responses
> approximately line up in subspaces, that's a mathematical fact; you can
> do arithmetic on the responses. Once you've
Dennis Roberts <[EMAIL PROTECTED]> wrote:
> inherent problems related to LICKert items and level of measurement that
> create problems would be these too
> 1. how many response categories are there for AN item??? by the way ...
> likert used many types ... including YES ? NO
> at THIS level ..
>here are a few videos of likert ...
http://ollie.dcccd.edu/mgmt1374/book_contents/3organizing/org_process/Likert.htm
_
dennis roberts, educational psychology, penn state university
208 cedar, AC 8148632401, mailto:[EMAIL PROTECTED]
http
At 11:45 AM 7/25/01 -0700, John Uebersax wrote:
>If your items are visually anchored so as to imply equal spacing,
>like:
>
> +++++
> 01234
> leastmost
> possiblepossible
of course, likert did not use a numerical scale like t
North Carolina,
are you?
John Uebersax
Teen Assessment Project <[EMAIL PROTECTED]> wrote in message
news:<[EMAIL PROTECTED]>...
> I am using a measure with likert scale items. Original psychometrics
> for the measure
> included factor analysis to reduce the 100 variables to
inherent problems related to LICKert items and level of measurement that
create problems would be these too
1. how many response categories are there for AN item??? by the way ...
likert used many types ... including YES ? NO
at THIS level ... i think it a bit presumptuous to think that we are
for a good treatment of this issue ... levels of measurement and statistics
to use ... though, it is not real simple ...
see
ftp://ftp.sas.com/pub/neural/measurement.html
warren sarle of SAS wrote this and, it is excellent
forget about scales and statistics for a moment ... what kinds of
STA
ent Project
> <[EMAIL PROTECTED]> wrote:
>
> > I am using a measure with likert scale items. Original psychometrics
> > for the measure
> > included factor analysis to reduce the 100 variables to 20 composites.
> > However, since the variables are not interval,
>
On Wed, 25 Jul 2001 07:26:19 -0400, Teen Assessment Project
<[EMAIL PROTECTED]> wrote:
> I am using a measure with likert scale items. Original psychometrics
> for the measure
> included factor analysis to reduce the 100 variables to 20 composites.
> However, since the
The following is extracted from one of my webpage. Hope it can help:
--
The issue regarding the appropriateness of ordinal-scaled data in
parametric tests was unsettled even in the eyes of Stevens (1951), the
inventor of the four levels of measurement: "As a matter of fact, most of
the s
Teen Assessment Project wrote:
>
> I am using a measure with likert scale items. Original psychometrics
> for the measure
> included factor analysis to reduce the 100 variables to 20 composites.
> However, since the variables are not interval, shouldn't non-parameti
At 07:26 AM 7/25/01 -0400, Teen Assessment Project wrote:
>I am using a measure with likert scale items. Original psychometrics
>for the measure
>included factor analysis to reduce the 100 variables to 20 composites.
>However, since the variables are not interval, shouldn't non
I am using a measure with likert scale items. Original psychometrics
for the measure
included factor analysis to reduce the 100 variables to 20 composites.
However, since the variables are not interval, shouldn't non-parametic
tests be done to determine group differences (by gender, age, i
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