60 PART 2 Examining Tools and Processes

»

» ^{PS (Power and Sample Size Calculation): The PS program was developed by}

W.D. Dupont and W.D. Plummer at Vanderbilt University. Like G*Power, you

download the application from its website and install it on your computer. The

PS interface is similar to that of G*Power. PS is available at https://biostat.

app.vumc.org/wiki/Main/PowerSampleSize.

Choosing Between Code-based and

Non–Code-Based Methods

Most of the software mentioned up to this point in this chapter — including SAS,

SPSS, R and Python — use code files that can be saved and rerun on data at a later

date. These programs run fundamentally differently from programs such as

Microsoft Excel, where you can run statistics on data, but no code files are pro-

duced and saved. Also, when you use web-based calculators, specialized apps like

G*Power and PS for sample-size calculations, or online commercial platforms, no

code files are produced and saved.

This is an important issue in statistics. When no code files are produced or saved,

you have no record of the steps in your analysis. If you need to be able to repro-

duce your analysis, the only way to be sure of this is to use software that allows

you to save the code so you can run it again.

Storing Data in the Cloud

Cloud-based storage refers to storing large data files on a set of Internet servers

designed specifically for large data storage. Unlike old-fashioned stand-alone

servers in server rooms, cloud-based servers share storage space across the Inter-

net, providing instantaneous access and back-up capabilities. If you want to get rid

of an old-fashioned server in your server room (that could be a SAS server), you will

have to contract with a cloud-based storage company to use its space for your data.

Then, you will have to find a way to move your data from your server into your new

cloud storage. You will also have to make sure you want to have a long-term rela-

tionship with this company, so you don’t have to move your data out anytime soon.

Although moving data to the cloud may be an onerous task, you may not have any

choice, because physical storage space may be running out. Many new organiza-

tions start with cloud data storage for that reason. Once your data are stored in the

cloud, they are more easily accessed using online analytics platforms such as SAS

Viya and Tableau.