CHAPTER 4 Counting on Statistical Software 59

Students often wonder what the differences are between R and Python, and which

one to learn. They are essentially the same, although scientific disciplines have

leaned toward adopting R, and engineering disciplines have leaned toward Python.

Many students find themselves easily learning both.

Other free statistical software

Other statistical software packages are free, but they are not technically open-

source — meaning they were not developed by an open-source community, and

they are not licensed the same way.

Software that performs many functions

This section provides examples of free software that performs many functions like

SAS and R.»

» ^{OpenStat and LazStats are free statistical programs developed by Dr. Bill}

Miller that use menus that resemble SPSS. Dr. Miller provides several

excellent manuals and textbooks that support both programs. OpenStat and

LazStats are available at https://openstat.info.»

» ^{Epi Info was developed by the United States Centers for Disease Control to}

acquire, manage, analyze, and display the results of epidemiological research.

What makes it different than other statistical software is that it contains

modules for creating survey forms and collecting data. Epi Info is available at

https://www.cdc.gov/epiinfo/index.html.

Software for calculating sample size

Biostatisticians frequently encounter the problem of estimating sample size. The

following are two free applications we recommend for performing sample-size

calculations:»

» ^{G*Power: G*Power was developed at the Universität Düsseldorf and is used}

to estimate the sample size for many different types of tests. Throughout this

book, when we discuss sample-size calculations, we give you advice on how to

do them using G*Power. G*Power is available at www.psychologie.hhu.de/

arbeitsgruppen/allgemeine-psychologie-und-arbeitspsychologie/

gpower. To use the program, you download it from this website and install it

on your computer.