R Programming Language Certification Professional Standards & Competencies 4

Question 1

Which R package provides tools for creating professional, publication-ready data visualizations aligned with best practices?

Accepted Answer

ggplot2, following the Grammar of Graphics framework

Answer

ggplot2's Grammar of Graphics framework enables consistent, layered, and publication-quality visualizations.

Question 2

What is the recommended way to handle credentials (API keys, passwords) in an R project?

Accepted Answer

Store them in environment variables or a .Renviron file excluded from version control

Answer

Environment variables keep credentials out of source code and version history, preventing accidental exposure.

Question 3

A professional submitting an R package to CRAN must ensure which of the following?

Accepted Answer

All examples, tests, and vignettes pass R CMD check with no ERRORs or WARNINGs

Answer

CRAN policy requires packages to pass R CMD check cleanly; errors and warnings are grounds for rejection.

Question 4

What is the professional standard for handling missing data in a published R analysis?

Accepted Answer

Document the extent of missingness, justify the handling method, and apply it consistently

Answer

Transparent documentation of missing data decisions allows readers to assess potential bias and reproduce the analysis.

Question 5

Which approach best supports accessibility when sharing R-generated reports?

Accepted Answer

Providing both visual charts and accompanying descriptive alt text or data tables

Answer

Alt text and data tables ensure that reports are usable by people relying on screen readers or who have color vision deficiencies.

R Programming Language Certification Practice Test