Independent Samples t-Test

🏥 Health Sciences · Independent Samples t-Test

Independent Samples t-Test

Parametric · Comparison
🆕 New in v1.0.5: A Chart tab was added to this analysis (boxplot, interaction, profile, bar, scatter, biplot, or forecast — depending on analysis type).

Independent Samples t-Test is one of the statistical analyses applied automatically in MerQur. This page illustrates — on a Health Sciences 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?

Independent Samples t-Test automatically performs all assumption checks required for the data type (normality, homogeneity of variance, etc.) in the background and presents the results in a clear table + chart. Automatic APA 7-formatted interpretation, effect sizes (Cohen’s d, η², R²) and 95% confidence intervals are reported.

📌 When is it used?

  • Statistical analysis of measurements in the Health Sciences 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 Independent Samples t-Test.

3

Panel assignments (form fields in the program):

  • Group Column: grup
  • Value Column: HbA1c_degisim
  • Equal variance: False
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 — Health Sciences

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 Health Sciences:

Tip/04_independent_t_drug_HbA1c.xlsx

🎬 Scenario

We compare the mean HbA1c change of two drug groups. With two separate groups and a continuous measure, the independent-samples t-test is appropriate.

⚙️ Variable Selection

  • Grouping (categorical): group
  • Test variable: HbA1c_change
  • >> ADVANCED PARAMETERS (optional in the form — what they do):
  • Hypothesis direction (two-sided / right / left).
  • Variance assumption: Student (equal var) / Welch (unequal var — safer) / Auto (Levene decides).
  • Effect sizes: Hedges g, Glass’s delta, CLES = P(X>Y).
  • Effect-size CI; per-group Shapiro; Levene & Bartlett homogeneity.
  • Per-group descriptives; Bootstrap CI for the mean difference.

Data Preview (First 5 Rows)

patient_idgroupHbA1c_changeage
14drug-0.9665
3drug-0.6468
26drug-1.9663
17drug-0.7558
20drug-1.145

n = 115 · Columns: patient_id, group, HbA1c_change, age

📈 MerQur Output

INDEPENDENT SAMPLES T-TEST RESULT ───────────────────────────────────────────── t(113) = -10.82 p < .001 *** Cohen d = -2.019 (Large) H0 REJECTED

💬 Interpretation

We compared the mean HbA1c change of two drug groups. The difference is significant and very large: t(113) = -10.82, p < .001, d = -2.02. It shows the between-group difference is too pronounced to be chance and is also clinically noteworthy. The independent-samples t-test is the standard way to compare the means of two separate groups (drug/placebo, two arms) on a continuous measure; in clinical research it is a fundamental tool for detecting differences between treatment arms. >> ADVANCED PARAMETERS (optional in the form — what they do): – Hypothesis direction (two-sided / right / left). – Variance assumption: Student (equal var) / Welch (unequal var — safer) / Auto (Levene decides). – Effect sizes: Hedges g, Glass’s delta, CLES = P(X>Y). – Effect-size CI; per-group Shapiro; Levene & Bartlett homogeneity. – Per-group descriptives; Bootstrap CI for the mean difference.

⚠ 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 Health Sciences file.

▶ Independent Samples t-Test — video walkthrough

A complete end-to-end walkthrough of this analysis in MerQur, narrated on screen. Narration is in Turkish.

▶ Watch the video 📺 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.