R Programming Language Certification Professional Standards & Competencies 2 — Questions and Answers
Question 1: Which practice best demonstrates reproducible research in R?
- Using R Markdown to combine code, output, and narrative (Correct answer)
- Saving only final results to CSV files
- Running scripts interactively without saving them
- Hardcoding absolute file paths in all scripts
Correct answer: Using R Markdown to combine code, output, and narrative
R Markdown integrates code, output, and documentation so analyses can be re-run and verified by others.
Question 2: A data scientist shares an R project with a colleague who cannot reproduce results due to different package versions. What is the best preventive measure?
- Use renv to snapshot and restore the project library (Correct answer)
- Email the colleague your entire R installation folder
- Hardcode all function outputs as constants
- Avoid using external packages altogether
Correct answer: Use renv to snapshot and restore the project library
renv creates a project-level lockfile recording exact package versions, enabling consistent environments across machines.
Question 3: When publishing a statistical analysis, which action upholds professional data integrity standards?
- Reporting all conducted tests, including non-significant results (Correct answer)
- Reporting only analyses that confirm the hypothesis
- Rounding p-values up to the nearest significant threshold
- Removing outliers without documenting the decision
Correct answer: Reporting all conducted tests, including non-significant results
Reporting all analyses, including null results, prevents publication bias and upholds scientific integrity.
Question 4: Which versioning strategy is recommended for collaborative R projects to track code changes?
- Git with a hosted repository such as GitHub or GitLab (Correct answer)
- Saving numbered copies of scripts like script_v1.R, script_v2.R
- Storing all versions in a single R script with commented-out sections
- Emailing updated scripts to team members after each change
Correct answer: Git with a hosted repository such as GitHub or GitLab
Git provides full change history, branching, and collaboration features essential for professional R projects.
Question 5: What does the principle of 'separation of concerns' mean in the context of an R project?
- Splitting data loading, processing, and reporting into distinct scripts or functions (Correct answer)
- Keeping all project code in a single script for portability
- Avoiding the use of functions to prevent complexity
- Storing raw and processed data in the same directory
Correct answer: Splitting data loading, processing, and reporting into distinct scripts or functions
Separation of concerns improves maintainability by assigning distinct responsibilities to different parts of the codebase.
Question 6: An R developer discovers that a widely-used function in their package has a critical bug. What is the professionally responsible next step?
- Release a patch version immediately and document the fix in NEWS.md (Correct answer)
- Quietly fix the bug without notifying users to avoid concern
- Deprecate the entire package and start over
- Wait for users to report the bug before acting
Correct answer: Release a patch version immediately and document the fix in NEWS.md
Releasing a patch promptly and documenting it transparently protects users and maintains trust in the package.
Question 7: Which R coding style guideline helps maintain consistent, readable code across a team?
- Following the tidyverse style guide and using tools like styler or lintr (Correct answer)
- Each developer using their own preferred naming conventions freely
- Minimizing whitespace to reduce file size
- Writing all code as one-liners for compactness
Correct answer: Following the tidyverse style guide and using tools like styler or lintr
Shared style guides enforced by automated tools like lintr reduce code review friction and improve readability.
R Programming Language Certification Professional Standards & Competencies 2
Which practice best demonstrates reproducible research in R?