Chapter 3.3. CALCULATION EXAMPLE FOR RUGGEDNESS TESTING OF MINOR CHANGES ACCORDING TO THE YOUDEN APPROACH (16)
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Comparison of averages (A)
| AA = Σ(Ai)/4 | Compare the averages of the capital letters (AA to AG) with the averages of their corresponding small letters (Aa to Ag). If a factor have an effect, the difference will be significant larger than the differences of the other factors. A robust method should not be affected by changes encountered almost certainly between laboratories. If there is no outstanding difference, the most realistic measure of the random error is given by the seven differences. |
| AB = Σ(Bi)/4 | |
| AC = Σ(Ci)/4 | |
| AD = Σ(Di)/4 | |
| AE = Σ(Ei)/4 | |
| AF = Σ(Ei)/4 | |
| AG = Σ(Gi)/4 | |
| Aa = Σ(ai)/4 | |
| Ab = Σ(bi)/4 | |
| Ac = Σ(ci)/4 | |
| Ad = Σ(di)/4 | |
| Ae = Σ(ei)/4 | |
| Af = Σ(fi)/4 | |
| Ag = Σ(gi)/4 |
| Differences (Di) | Squares of differences (Di2) |
|---|---|
| Da = A – a = Σ(Ai) – Σ(ai) | Da2 = value a |
| Db = B – b = Σ(Bi) – Σ(bi) | Db2 = value b |
| Dc = C – c = Σ(Ci) – Σ(ci) | Dc2 = value c |
| Dd = D – d = Σ(Di) – Σ(di) | Dd2 = value d |
| De = E – e = Σ(Ei) – Σ(ei) | De2 = value e |
| Df = F – f = Σ(Fi) – Σ(fi) | Df2 = value f |
| Dg = G – g = Σ(Gi) – Σ(gi) | Dg2 = value g |