[R] Interpreting fa.diagram from package psych

Ebert,Timothy Aaron tebert @end|ng |rom u||@edu
Mon Sep 12 13:42:14 CEST 2022

Ok, in looking at the code that makes more sense. The code specifies three groups, so there will be three colors. As the groups do not have meaning (hopefully supplied by the user at a later date) there is no legend. They are there to help the user see overlap between groups (none in this case).

-----Original Message-----
From: David Winsemius <dwinsemius using comcast.net> 
Sent: Sunday, September 11, 2022 11:50 PM
To: Ebert,Timothy Aaron <tebert using ufl.edu>; Luigi Marongiu <marongiu.luigi using gmail.com>
Cc: r-help <r-help using r-project.org>
Subject: Re: [R] Interpreting fa.diagram from package psych

[External Email]

On 9/11/22 07:17, Ebert,Timothy Aaron wrote:
> It is a bad graphic as the legend that should explain the color coding is missing. The next option is to copy the data and code and see if you can reproduce the figure. You can then play with the code and read a bit about the procedures to figure out what is going on. It should not be too hard. My guess is that there is some additional variable with three states that is being used. If this were the iris data set I would guess it was the three species: setosa, versicolor, and virginica.

Pretty sure that guess is incorrect.

I'm not sure there should be a legend. The colors just indicate group membership derived from a mathematical process that has attempted to separate case into distinct groups that maximize the correlations within individual groupings. And therefore maximizes the distance separating the groups. The number of groups is specified in the function call. You should go to the earlier results and see if you can construct the groupings to maximize internal correlations. Psychometricians do this when they don't really have a theoretical basis for doing classification and are asking the data do it for them. If they are doing this on a questionnaire dataset, they often go back to the specific questions/answer pairings within groupings and try to assign meaning to them.  They then build post-hoc explanations and often do further studies to see if they can replicate the results and achieve some sort of stable synthetic construct.  It's a rather theory-free strategy and so trying to assign labels automatically would be difficult.



> Tim
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Luigi 
> Marongiu
> Sent: Sunday, September 11, 2022 3:02 AM
> To: David Winsemius <dwinsemius using comcast.net>
> Cc: r-help <r-help using r-project.org>
> Subject: Re: [R] Interpreting fa.diagram from package psych
> [External Email]
> Sorry, the file was automatically downloaded and opened with the browser instead of pointing to the webpage.
> Here is a better link:
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcran
> .r-project.org%2Fweb%2Fpackages%2FpsychTools%2Fvignettes%2Ffactor.pdf&
> amp;data=05%7C01%7Ctebert%40ufl.edu%7C1dcd24dd7d3f415768d308da9471f65d
> %7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C637985514593519914%7CUnk
> nown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWw
> iLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=lzFXWWfT0dWdXegsbLDuh5RcdW79
> xJXTsN%2Bkj%2FuMrxo%3D&reserved=0
> The figure is on page 22.
> The question is: The dots have different colors; how do I know what they represent?
> Is there a way to show an auto-legend?
> Thank you
> On Sat, Sep 10, 2022 at 11:33 PM David Winsemius <dwinsemius using comcast.net> wrote:
>> On 9/10/22 14:08, Luigi Marongiu wrote:
>>> Hello,
>>> I have plotted data from exploratory factor analysis, and I got a 
>>> graph similar to FIGURE 11 (PAGE 36) of this link 
>>> file:///home/gigiux/Downloads/An_overview_of_the_psych_package.pdf
>> This appears to be a link you a file on your personal device rather 
>> than an attachment.
>>> How do I interpret the figure? In particular, how do I know what the 
>>> colors represent?
>>> Thank you
> --
> Best regards,
> Luigi
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat
> .ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl
> .edu%7C1dcd24dd7d3f415768d308da9471f65d%7C0d4da0f84a314d76ace60a62331e
> 1b84%7C0%7C0%7C637985514593519914%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C
> &sdata=hZSv1rtzkhlgMUvJO6jmHN1IIUDsVIa8PVeAo8KE0%2Fw%3D&reserv
> ed=0 PLEASE do read the posting guide 
> https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r
> -project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu%
> 7C1dcd24dd7d3f415768d308da9471f65d%7C0d4da0f84a314d76ace60a62331e1b84%
> 7C0%7C0%7C637985514593519914%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM
> DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&
> sdata=oxdhuTBv3NWlhalSpYYVYa6zIfpoaqLgUzRfCXxc%2FbQ%3D&reserved=0
> and provide commented, minimal, self-contained, reproducible code.

More information about the R-help mailing list