Why Descriptive Statistics Matter in APA Papers
Every quantitative research paper begins with descriptive statistics. Before you run a t-test, ANOVA, or regression, your readers need to understand the basic characteristics of your data: how variables are distributed, where the center lies, and how much spread exists.
APA 7th edition requires that you report descriptive statistics for all study variables, typically before presenting inferential results. Reviewers routinely flag manuscripts that jump straight to hypothesis testing without first describing the sample. Beyond satisfying formatting requirements, well-reported descriptive statistics help readers evaluate whether your data are suitable for the analyses you performed.
This guide covers the exact APA format for reporting means, standard deviations, frequencies, percentages, medians, ranges, skewness, and kurtosis. Each section includes copy-ready templates you can adapt for your manuscript.
Reporting Means and Standard Deviations
The mean (M) and standard deviation (SD) are the most commonly reported descriptive statistics. APA format uses italicized abbreviations enclosed in parentheses when reported in running text.
In-Text Format
The basic template for a single group is:
Participants reported moderate levels of anxiety (M = 25.40, SD = 5.32).
Note the formatting details: M and SD are italicized, there are spaces around the equals signs, and values are rounded to two decimal places. The period falls outside the closing parenthesis when the statistics end the sentence.
Comparing Multiple Groups
When comparing two or more groups in text, report each group's M and SD so readers can see the pattern before your inferential test:
The experimental group (M = 82.40, SD = 10.25) scored higher than the control group (M = 74.60, SD = 11.30) on the post-test.
For three or more groups, in-text reporting becomes unwieldy. In that case, present the descriptive statistics in a table and refer to it:
Table 1 presents the means and standard deviations of test scores across the three instructional conditions.
Rounding Rules
APA 7th edition provides clear rounding guidance:
| Statistic | Decimal Places | Example | |-----------|---------------|---------| | M (mean) | 2 | M = 25.40 | | SD (standard deviation) | 2 | SD = 5.32 | | n / N (sample size) | 0 (whole numbers) | N = 120 | | Percentages | 1 or 0 (context-dependent) | 37.5% or 38% | | p values | 3 (exact) | p = .007 |
Always report trailing zeros. Write M = 25.40, not M = 25.4. This signals that your measurement was precise to two decimal places.
APA Descriptive Statistics Table Format
When you have three or more groups, multiple dependent variables, or both, a table is the most efficient way to present descriptive statistics. APA tables follow strict formatting rules.
Table Structure
An APA table has five components: number, title, column headers, body, and note. Here is a template for a three-group comparison:
Table 1
Descriptive Statistics for Test Scores by Instructional Condition
| Variable | Lecture (n = 40) | Discussion (n = 38) | Blended (n = 42) | |----------|------|------|------| | Pre-test M (SD) | 68.25 (9.41) | 67.80 (10.12) | 69.10 (8.95) | | Post-test M (SD) | 74.60 (11.30) | 82.40 (10.25) | 80.15 (9.87) | | Gain score M (SD) | 6.35 (4.20) | 14.60 (5.80) | 11.05 (4.65) |
Note. Gain score = Post-test minus Pre-test. Scores range from 0 to 100.
Table Formatting Rules
- Table number appears on its own line in bold: Table 1
- Table title is italicized and placed on the line below the number. Use title case.
- Column headers should identify the group and sample size.
- Body contains the values with consistent decimal places throughout each row.
- Note appears below the table in italics, beginning with Note. (italicized, followed by a period). Use it to explain abbreviations, scoring ranges, or data transformations.
When to Use a Table vs. In-Text Reporting
A simple guideline: if you can report the descriptive statistics in one or two sentences, keep them in the text. If doing so would require three or more sentences of numbers, use a table. Tables with fewer than two rows and two columns of data are usually unnecessary.
Reporting Frequencies and Percentages
For categorical variables, you report frequencies (n) and percentages rather than means and standard deviations.
In-Text Format
Of the 120 participants, 45 (37.5%) identified as first-generation college students.
Or when listing multiple categories:
The sample included 68 women (56.7%), 47 men (39.2%), and 5 nonbinary participants (4.2%).
Note that n (lowercase, italicized) refers to a subset, while N (uppercase, italicized) refers to the total sample.
Frequency Table Format
For variables with many categories, use a table:
Table 2
Demographic Characteristics of Participants (N = 120)
| Characteristic | n | % | |---------------|-----|------| | Gender | | | | Women | 68 | 56.7 | | Men | 47 | 39.2 | | Nonbinary | 5 | 4.2 | | Education level | | | | Bachelor's | 52 | 43.3 | | Master's | 45 | 37.5 | | Doctoral | 23 | 19.2 |
Cross-Tabulation Reporting
When two categorical variables are cross-tabulated, report the joint frequencies:
Among women, 34 (50.0%) were in the experimental condition and 34 (50.0%) were in the control condition. Among men, 28 (59.6%) were in the experimental condition and 19 (40.4%) were in the control condition.
If the cross-tabulation has many cells, present it as a contingency table rather than in text.
Reporting Medians and Ranges
When Median Is Preferred Over Mean
The median (Mdn) is reported instead of, or alongside, the mean when your data are skewed, contain outliers, or are measured on an ordinal scale. Common scenarios include income data, response time data, and Likert-scale items analyzed individually.
APA Format for Medians and Ranges
Response times were positively skewed, so medians are reported. Participants responded faster in the congruent condition (Mdn = 450 ms, Range = 280–820 ms) than in the incongruent condition (Mdn = 620 ms, Range = 340–1,240 ms).
You can also report the interquartile range (IQR) for a more robust measure of spread:
Annual household income was right-skewed (Mdn = $52,000, IQR = $38,000–$74,000).
Range Formatting
Use an en dash (–), not a hyphen (-), between the minimum and maximum values: Range = 5–28. When the range includes negative numbers, use "to" instead of a dash for clarity: Range = -3 to 12.
Reporting Skewness and Kurtosis
When to Include These
Skewness and kurtosis are typically reported in two situations: (1) when you need to justify using parametric tests by demonstrating approximate normality, and (2) when screening your data for distributional assumptions.
They are not required in every paper, but reviewers in fields like psychology and education increasingly expect them, especially when sample sizes are small.
Acceptable Ranges
A commonly cited guideline is that skewness and kurtosis values between -2.0 and +2.0 indicate approximate normality (George & Mallery, 2019). Some researchers use a stricter criterion of -1.0 to +1.0.
APA Format
Report skewness and kurtosis in a descriptive statistics table or in text:
The distribution of test scores was approximately normal (skewness = -0.34, kurtosis = 0.18).
Or in a table, add columns for skewness and kurtosis:
| Variable | M | SD | Skewness | Kurtosis | |----------|------|------|----------|----------| | Anxiety | 25.40 | 5.32 | -0.34 | 0.18 | | Depression | 18.75 | 6.10 | 0.82 | -0.45 | | Life satisfaction | 22.60 | 4.88 | -0.12 | -0.67 |
When skewness or kurtosis exceeds acceptable ranges, note the transformation applied or explain why you chose a non-parametric alternative.
Common Mistakes in Reporting Descriptive Statistics
Not Reporting SD Alongside M
A mean without a standard deviation is incomplete. The SD communicates how much individual scores vary around the mean. Without it, the reader cannot evaluate the overlap between groups or the practical significance of differences. Always pair M with SD.
Wrong Number of Decimal Places
Reporting M = 25.4 instead of M = 25.40 is a formatting error. Inconsistent decimal places within the same table (e.g., 25.4 in one cell and 10.25 in another) signal carelessness. Maintain two decimal places throughout, with trailing zeros where needed.
Forgetting Sample Size Per Group
Readers need to know how many participants are in each group to interpret the statistics. Always report n for subgroups and N for the total sample. Place these in table headers or in the text alongside group descriptives.
Using Tables When In-Text Would Suffice
A table showing descriptive statistics for a single variable in two groups wastes space. Two groups with one dependent variable can be reported in a single sentence:
The treatment group (M = 78.30, SD = 9.45, n = 35) and control group (M = 72.10, SD = 10.20, n = 33) differed in post-test scores.
Reserve tables for more complex data.
Reporting Descriptive Statistics Without Context
Raw numbers need interpretation. After presenting M = 25.40, SD = 5.32, briefly explain what the scale measures and what the values mean. For example, note the possible range of the scale and what higher scores indicate.
Omitting Descriptive Statistics Entirely
Some researchers skip descriptive statistics and go straight to inferential tests. APA 7th edition is explicit that sufficient statistics should be presented to allow the reader to fully understand the analyses. This always includes at minimum M, SD, and N (or n) for each group.
Descriptive Statistics Checklist
Before submitting your manuscript, verify each of the following:
| Check | Requirement | |-------|-------------| | M and SD reported | Every continuous variable has both M and SD | | Sample sizes included | N for total sample, n for each subgroup | | Consistent decimal places | Two decimal places for M and SD, trailing zeros included | | Italicization correct | M, SD, Mdn, N, n, p are all italicized | | Frequencies and percentages | Categorical variables include both n and % | | Table formatting | Number, italicized title, headers, body, note | | Scale context provided | Possible range and direction of scoring explained | | Normality addressed | Skewness/kurtosis reported when assumptions are checked | | No redundancy | Data are in tables or text, not duplicated in both | | APA leading zero rule | Leading zero included for M, SD, Cohen's d; omitted for p, r, R² |
Calculate Descriptive Statistics Instantly with StatMate
Formatting descriptive statistics correctly takes time, especially when you are juggling multiple variables, groups, and APA rules simultaneously. StatMate's free Descriptive Statistics Calculator computes all the values covered in this guide and formats them in APA 7th edition style automatically.
Enter your data or upload a CSV file, and StatMate returns:
- Mean, standard deviation, and standard error with proper rounding
- Median, range, and interquartile range for non-normal distributions
- Skewness and kurtosis with normality assessment
- Frequency counts and percentages for categorical summaries
- APA-formatted results ready to copy and paste into your manuscript
The calculator also generates a histogram and box plot so you can visually inspect your distribution before deciding between parametric and non-parametric approaches. All output follows APA 7th edition conventions, eliminating manual formatting errors and saving hours of writing time.
Try it free at statmate.org/calculators/descriptive.