Normality Tests

🧪 Natural Sciences & Mathematics · Normality Tests

Normality Tests

Parametrik · Dağılım Kontrolü

Normality Tests is one of the statistical analyses applied automatically in MerQur. This page illustrates — on a Natural Sciences & Mathematics sample dataset — how the analysis is run, what the MerQur output looks like, and how the result is reported in APA 7 format.

🎯 What is it for?

Normality Tests automatically applies all necessary assumption checks (normality, homogeneity of variance, etc.) for the relevant data type in the background and presents the results with a clear table + chart. Automated interpretation to the APA 7 standard, effect sizes such as Cohen’s d/η²/R², and 95% confidence intervals are reported.

📌 When is it used?

  • Statistical analysis of measurements in the Natural Sciences & Mathematics domain
  • To produce APA 7-compatible result tables for academic publications
  • Hypothesis testing and decision-making processes
  • Undergraduate / master’s / PhD theses after the appropriate method has been selected

📐 Assumptions

  • Appropriate scale — Variables must be at the measurement level required by the analysis (nominal/ordinal/interval/ratio)
  • Independent observations — Observations must come from individuals independent of one another
  • Sufficient sample size — The minimum n requirement for the analysis must be met
  • Outlier check — Outliers must be detected and evaluated

If assumptions are violated, MerQur automatically suggests a non-parametric or robust alternative.

🛠 How to do it in MerQur

1

Load the data. Select the sample file from File → Open. MerQur auto-detects column types.

2

Select the analysis. From the left side select Normality Tests.

3

Panel assignments (form fields in the program):

  • Column: ornek_id
  • Significance (α): 0.05
4

Optional settings. Effect size ✓ · 95% confidence interval ✓ · Assumption checks (automatic).

5

▶ Run — click the button. Results are produced automatically as a table + chart.

6

📄 Export to Word. APA 7-formatted report with italic statistical symbols.

📊 Sample Dataset — Natural Sciences & Mathematics

ℹ Note: The scenario, MerQur output and interpretation below were produced by actually running the real example dataset in MerQur. Numeric results on your own data will differ; the goal is to show how the analysis is set up and interpreted end-to-end.

🎬 Example File

This analysis is demonstrated on the following example dataset for Natural Sciences & Mathematics:

Fen_Matematik/02_normality_chemical.xlsx

🎬 Scenario

We examine whether concentration, reaction rate and molecule weight are normally distributed. Because the validity of subsequent t-tests, ANOVA and correlation depends on this assumption, we test each variable separately.

⚙️ Variable Selection

  • Variables: concentration_mM
  • Variables: reaction_rate
  • Variables: molecule_weight

Data Preview (First 5 Rows)

sample_idconcentration_mMreaction_ratemolecule_weight
1.022.54.17208.0
2.026.1512.26134.0
3.024.3810.04311.0
4.032.927.3197.0
5.022.262.1173.0

n = 200 · Columns: sample_id, concentration_mM, reaction_rate, molecule_weight

📈 MerQur Output

NORMALITY TESTS RESULT ───────────────────────────────────────────── 3 continuous variables tested: concentration_mM : Shapiro-Wilk = 0.994 p = 0.542 KS p = 0.647 Normal reaction_rate : Shapiro-Wilk = 0.900 p < .001 KS p = 0.001 Not Normal molecule_weight : Shapiro-Wilk = 0.842 p < .001 KS p = 0.001 Not Normal

💬 Interpretation

We tested whether three continuous variables — concentration, reaction rate and molecule weight — are normally distributed. The result splits instructively: concentration is normal (p = 0.54), but reaction rate and molecule weight deviate significantly from normality (p < .001). This is typical in chemical data — reaction rates and weight distributions are often right-skewed. Practical upshot: we can safely use parametric tests (t-test, ANOVA, Pearson) on concentration; for reaction rate and molecule weight, nonparametric methods (Mann-Whitney/ Kruskal-Wallis) or a transform are more appropriate. The normality check is a critical preliminary step that decides, per variable, which test family fits.

⚠ Common Mistakes

  • Misidentifying the data type (e.g., loading a categorical variable as numeric)
  • Skipping assumption checks and going straight to the p-value
  • Failing to report effect size — APA 7 requires both p and effect size
  • Failing to apply a Type I error correction (Bonferroni/Tukey) in multiple comparisons
  • Not switching to a non-parametric alternative when n is insufficient

📹 Video Walkthrough

Watch the video below for an end-to-end walkthrough of this analysis on a Natural Sciences & Mathematics file.

▶ Normality Tests — video walkthrough

This section is part of the Veriye İlk Bakış ve Parametrik Testler video (14 analyses in one video). The link below jumps straight to 2:40, where this analysis begins. Narration is in Turkish.

▶ Watch this analysis (2:40) 📺 All videos

📚 If You Used This Analysis, Cite MerQur

If you performed this analysis using MerQur in a scientific study, please use the citation below as part of your academic citation obligations (APA 7):

Örücü, Ö. K. (2026). MerQur: Integrated Academic Data Analysis & Reporting Platform [Computer software] (Version 1.0.0). https://doi.org/10.53463/merqur.2026001

For BibTeX, RIS, EndNote and the English citation form: all citation formats →

Sources:
  1. American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.).
  2. Field, A. (2018). Discovering statistics using IBM SPSS Statistics (5th ed.). Sage.
  3. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Lawrence Erlbaum.