Quick answer: R Commander gives you three descriptive routes: Statistics → Summaries → Active data set (everything at once), Numerical summaries (mean/SD/quantiles per variable, grouped if you like), and Graphs (histograms, boxplots, bar plots). Descriptives are never optional: they check data sanity, reveal outliers, and tell you which inferential test the data will tolerate. Import logistics are in our data import guide; here we focus on the summaries themselves.
Table of Contents
The three routes, and when to use each
| Route | Menu path | Use when |
|---|---|---|
| Whole-dataset summary | Statistics → Summaries → Active data set | First look: n, missing, mean, quartiles for every column |
| Numerical summaries | Statistics → Summaries → Numerical summaries | Chosen variables, optional grouping factor, chosen stats |
| Frequency distributions | Statistics → Summaries → Frequency distributions | Categorical variables: counts and percentages per level |
Reading the numerical output like a pro: compare mean vs median — a mean notably higher than the median means right-skew (income, length-of-stay, growth curves) and flags the outliers a histogram would show. SD vs IQR tells the robustness story; and n per variable exposes missingness patterns before they surprise a t-test. What those distributions mean statistically — and why skew matters for test choice — is in our distributions guide.
The graphs that earn their place
- Histogram (Graphs → Histogram): the shape check before any t-test or ANOVA — normal-ish, skewed, bimodal?
- Boxplot (Graphs → Boxplot): group comparisons at a glance and the fastest outlier detector; tick Identify outliers with mouse to label points interactively.
- Bar/line + quantile-comparison plot (Graphs → QQ plot): the normality eyeball that pairs with Shapiro-Wilk when reviewers ask.
One commandment: report descriptives in a table (per group: n, mean, SD, median, min–max) before any p-value appears — the APA-style habit that examiners and reviewers reward. The full logic of why descriptives gate inference is in the introduction to biostatistics, and the descriptive-first workflow with menus-only software is paralleled in our jamovi first-analysis guide.
Next stop: the tests
When descriptives are on paper, the inferential catalog — t-tests, ANOVA, chi-square, correlations, non-parametrics — is mapped menu-by-menu in statistical tests in R Commander; and if you haven’t installed R Commander yet, the two-minute setup is in the installation guide. For one-to-one practice describing real datasets, Ampersand Academy teaches R and statistics one-to-one.
Official documentation
For the full reference behind this guide, read the R Commander package page on CRAN. It is the source the details above are drawn from, and the first place to check when an option or attribute name changes.
Frequently asked questions
How do I get summary statistics in R Commander?
Statistics menu, Summaries. Active data set summarizes every column at once; Numerical summaries lets you pick variables, statistics and an optional grouping factor; Frequency distributions handles categorical variables.
What does it mean when the mean is much larger than the median?
The variable is right-skewed – a few large values pull the mean up. Report the median and interquartile range instead, and consider rank-based tests rather than t-tests for inference.
How do I make a histogram or boxplot in R Commander?
Graphs menu: Histogram for distribution shape, Boxplot for group comparison and outliers. Both ask for the variable, and the boxplot can label outliers with a mouse click.
How do I group summaries by a factor?
In the Numerical summaries dialog, move the grouping variable into the Summarize by groups box. Every statistic is then reported per level – the descriptives table most reports require.
Which descriptive statistics belong in a thesis table?
Per group: sample size, mean, standard deviation, and for skewed variables the median with interquartile range. Add minimum and maximum where ranges inform readers. This one table precedes every inferential test.
Last updated on · Written by Dinesh Kumar R
