Augmented RBD Calculator

Augmented RBD analysis with checks and unreplicated test entries. Adjusted means and SE of differences.

Open the Augmented Design (RBD) calculator

When to use it

Use when there are many test entries with limited seed (typical of early breeding generations: F2, F3, head rows) but a small set of replicated check varieties. The replicated checks anchor the block adjustment, and unreplicated test entries are evaluated by adjusted means.

When NOT to use it

Do not use when seed is sufficient to replicate every test entry; an RBD or alpha lattice gives more reliable comparisons. Do not use when blocks have very different sizes; the analysis assumes a clean RBD layout for the checks.

What you get

Adjusted means for every test entry (the check-anchored block correction); standard errors for test-vs-test, test-vs-check, and check-vs-check comparisons (each is a different SE because of how augmentation works); ANOVA on the checks; a CV percent based on the check error; ranking table for the test entries.

How to interpret the output

Adjusted means are the right unit for ranking test entries; they remove block effects estimated from the checks. SE of test-vs-test is larger than SE of test-vs-check because test entries are unreplicated. Tests are most useful for screening (rank-order decisions); confirm top candidates in a replicated trial the next season. Federer 1956 is the original reference.

Common pitfalls

Reading raw test means instead of adjusted means.
Confusing the three SE values (test-test, test-check, check-check).
Using the design when seed is actually sufficient for replication.
Treating significant tests of test-vs-check as a complete answer (always re-test the top performers).

Try it in StatVeda

The Augmented Design (RBD) engine runs entirely in the browser. No signup, no install, no data sent to a server. Paste your data, hit Run, copy the output.

Open Augmented Design (RBD)

References

Federer, W. T. (1956). Augmented (or hoonuiaku) designs. Hawaiian Planters' Record, 55, 191 to 208.
Cochran, W. G. and Cox, G. M. (1957). Experimental Designs, 2nd edition. John Wiley and Sons, New York.
Federer, W. T. and Raghavarao, D. (1975). On augmented designs. Biometrics, 31(1), 29 to 35.