Statistics & Probability / One-Way ANOVA F-Test
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LABORATORY 31 · STATISTICS & PROBABILITY

One-Way Analysis of Variance (ANOVA), Between/Within Sum of Squares, and F-Test Significance

Decompose total variance in multi-group experimental designs, compute Between-Group Sum of Squares (SSB) and Within-Group Sum of Squares (SSW), evaluate the omnibus F-statistic, and verify the F-ratio scaling law. Explore interactive statistical sampling, probability models, and empirical regression.

SAMPLE · INFER · CONVERGE

Your virtual statistics laboratory.

EXPECTED OMNIBUS F-STATISTIC E[F]—
SAMPLING TELEMETRY

Ready to sample with Factor k = 1.0.

1.0 factor
k = 3 treatment groups with n = 10 subjects per group

Adjust Factor k, then execute statistical trial.

Probabilistic samples are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity empirical probability functions.

Statistical assumptions and distribution limits

ANOVA tests for differences in means, but is sensitive to variance heterogeneity when group sizes are unequal. The empirical regression of omnibus F-statistics against treatment factor k confirms theoretical variance decomposition with slope m = 1.5000 and R² = 1.000000.

Statistical tools & sampling modules.

Multi-Group Gaussian Generator

Generates k independent treatment groups with specified group means μ_j and common within-group variance σ^2.

Sum of Squares Decomposer

Partitions total sum of squares SST into between-group sum of squares SSB and within-group error sum of squares SSW.

ANOVA Mean Square Table Engine

Computes Mean Square Between MSB = SSB/(k-1) and Mean Square Within MSW = SSW/(N-k).

Omnibus F-Test Resolver

Evaluates the variance ratio F = MSB / MSW and determines exact upper-tail p-values from F(k - 1, N - k).

Eta-Squared Effect Size Meter

Computes proportion of total variance explained by treatment: η² = SSB / SST.

ANOVA F-Ratio Regression Unit

Performs linear regression of expected F-statistic versus treatment factor k to confirm the slope m = 1.500.

FOLLOW THE METHOD

A reason behind every step.

Decompose total variance in multi-group experimental designs, compute Between-Group Sum of Squares (SSB) and Within-Group Sum of Squares (SSW), evaluate the omnibus F-statistic, and verify the F-ratio scaling law. Standardized parameter settings: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 factor.

01

Configure Multi-Group Experimental Design

Set group count to k = 3 treatments with balanced sample sizes n = 10 per group (total N = 30) on the ANOVA control interface.

02

Synthesize Baseline Observations under H_0

Generate all groups from standard normal N(0, 1) with equal means μ_1 = μ_2 = μ_3 = 0.0. Verify grand mean x̄_grand ≈ 0.0.

03

Perform Orthogonal Variance Decomposition

Compute total sum of squares SST, between-group sum of squares SSB, and within-group sum of squares SSW. Confirm SST = SSB + SSW.

04

Evaluate Omnibus F-Distribution under H_0

Compute F = MSB / MSW across 20,000 runs under the null. Verify that empirical mean F matches E[F] = (N - k)/(N - k - 2) = 27/25 = 1.080.

05

Step Treatment Effect Across Factor k = 1 to 6

Inject systematic treatment shifts across standardized settings k ∈ {1.0, 2.0, 3.0, 4.0, 5.0, 6.0}, recording the omnibus F-statistic.

06

Conduct Linear Regression on ANOVA Scaling

Fit a linear regression model y = mx to coordinate pairs (x = k, y = E[F]). Confirm that empirical slope m = 1.5000 validates non-central F response.

YOUR NOTEBOOK · 0 OBSERVATIONS

Turn measurements into empirical insight.

See a complete example report ↗

Points are your recorded observations. The solid regression line validates One-Way ANOVA F-Test mathematical scaling.

LINEAR REGRESSION FIT · y = mx + b
y = 1.5000 · x
#Treatment Effect Magnitude Factor k (factor)Expected Omnibus F-Statistic E[F] (F-Statistic)Treatment Effect Factor kExpected Omnibus F-Statistic E[F]Remove

No readings yet. Execute a statistical trial and record it.

Calculate it yourself.

CHECK YOUR UNDERSTANDING

Explain what the statistical metrics mean.

In a one-way ANOVA with k groups and total sample size N, what are the degrees of freedom for the Within-Group (Error) Mean Square?

What is the primary danger of performing multiple pairwise t-tests instead of an omnibus ANOVA?

Which post-hoc test is specifically designed to control the family-wise error rate across all pairwise comparisons using the studentized range distribution?

What does the effect size metric Eta-squared (η²) measure in ANOVA?