It’s always a good idea to check the help information for a function before using it. Don’t necessarily assume a function will perform a test as you think it will. The help information will give the options available for that function, and often those options make a difference with how the test is carried out.

### Help in R

In order to see the help file for the *chisq.test*
function:

?chisq.test

In order to specify the *chisq.test* function in the *stats*
package, you would use:

?stats::chisq.test

or

help(chisq.test, package=stats)

In order to search all installed packages for a term:

??"chi-square"

In order to view the help for a package

help(package=psych)

### CRAN documentation

Documentation for packages is also available in a .pdf format, which may be more convenient than using the help within R. Also very helpful, some packages include vignettes, which describe how a package might be used.

For a list of available packages, visit cran.r-project.org/web/packages/available_packages_by_name.html.

And clicking on the link for the *psych* package will
bring up a page with a link for the .pdf documentation, two .pdf vignettes, and
other information.

### Summary and Analysis of Extension Program Evaluation in R

Most of the analyses in this book are also presented in *Summary and Analysis of Extension Program Evaluation in R* (SAEPER, html). Or as a pdf: *.pdf
link* .

It may be useful for the reader to consult that book for additional examples and discussion.

### Other online resources

Since there are many good resources for R online, an internet search for your question or analysis including the term “r” will often lead to a solution. The reader is cautioned, however, to always check the original R documentation on functions to be sure it will perform an analysis as the user desires.

A convenient tool is the *RSiteSearch* function, which
will open a browser window and search for a term in functions and vignettes
across a variety of sources:

RSiteSearch("chi-square")

This tool can also be accessed from: search.r-project.org/.