Hi Michael, See comments in line.
On Wed, Sep 4, 2013 at 10:18 PM, Michael Hacker <mhac...@nycap.rr.com> wrote: > Dear Colleagues, > > > > I'm working on a Delphi study comparing perceptions of high school > technology teachers and university engineering educators about the > importance of concepts about engineering for HS students to learn as part of > their fundamental education. I'm actually doing this as part of my Ph.D. > > The survey items (n=37) are categorized into five scales: design, human > values, modeling, resources, and systems thinking. I'm seeking to determine > the reliability of these scales and of the overall survey instrument. Since > I'm working with ordinal data, Chronbach's Alpha probably isn't the best > statistical tool to use. > > > > I've literally spent several days learning my way around R-project but am > struggling with procedures and interpretations. > > > > I'm aware that there is now a plug-in for R for SPSS that can be downloaded > ( <http://www-01.ibm.com/support/docview.wss?uid=swg21477550> > http://www-01.ibm.com/support/docview.wss?uid=swg21477550 and > <http://gruener.userpage.fu-berlin.de/Essentials%20for%20R%20Installation%20 > Instructions_21.pdf> > http://gruener.userpage.fu-berlin.de/Essentials%20for%20R%20Installation%20I > nstructions_21.pdf). Just learned that today and I downloaded > PolyCorrelations.zip from > https://www.ibm.com/developerworks/community/files/app?lang=en#/file/9f47f9a > 0-7793-4ad5-8bb7-d3fd1a028e44 > > I would ditch the SPSS/R integration and just run R from RCommander. You don't need PollyCorrelations.zip or SPSS for this, and trying to get the R and SPSS talking to each other is just another level of complication that you don't need. > > I've gotten as far as loading Rcmdr and running some analyses - (Statistics, > dimensional analysis, scale reliability) and I've generated this output: > > > > Reliability deleting each item in turn: > > Alpha Std.Alpha r(item, total) > > design 0.8445 0.8490 0.7629 > > humanvalues 0.8526 0.8541 0.7170 > > modeling 0.8511 0.8546 0.7271 > > resources 0.8712 0.8757 0.6328 > > systems 0.8461 0.8498 0.7488 > > > > I now would sincerely appreciate some help. At the age of 70, never having > studied programming, the meaning of these statistics is not apparent. Understanding these statistics has nothing to do with studying programming. You need to study statistics! > > For example, I'm not clear if either of these three statistics are Ordinal > Alpha. Since I'm working with Likert scale items, my advisor suggested that > I seek an alternative to Chronbach's Alpha to determine reliability. Since we have no idea how you calculated these statistics there is no way for us to answer this question. > > > > So far, here are the steps I have taken: > > I've searched the FAQs > > Searched specifically for answers on the Web > > Played with the software for hours > > Read the accompanying documentation. > > Downloaded and installed Rcmdr > > Downloaded and installed PolyCorrelations. > > > > I tried running PolyCorrelations but I get a message that states that this > requires the Polychor and Gclus libraries. I tried to install them into the > R console, but no luck. What does "no luck" mean? > > > > I'd also be pleased to work with someone-on-one on a consulting basis if > someone has the time and inclination. Hoping to find an individual who > knows SPSS and R. Appendix B of http://pareonline.net/pdf/v17n3.pdf shows how to calculate reliability from ordinal data using R. Best, Ista > > > > Thanks very sincerely for considering this request. > > > > Michael > > > > > > -------------------------------- > > END OF MESSAGE > > -------------------------------- > > Michael Hacker, Co-Director > > Hofstra University Center for STEM Education Research > > Ph: 518-724-6437 > > Cell: 518-229-7300 > > Fax: 518-434-6783 > > URL: www.Hofstra.edu/CSR > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
