Sign Test (Paired)
Computes the sign test, the simplest and most robust paired test of all. It completely ignores the magnitude of the differences between pairs and looks only at the sign: how many times the value went up and how many it went down. Under the hypothesis of no effect, ups and downs should balance out, like heads and tails, and the p-value comes straight from a binomial distribution. Because it uses so little information, it's less powerful than Wilcoxon, but it makes almost no assumptions. Enter the two paired series.
Resultado
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Sign Test (Paired)
Computes the sign test, the simplest and most robust paired test of all. It completely ignores the magnitude of the differences between pairs and looks only at the sign: how many times the value went up and how many it went down. Under the hypothesis of no effect, ups and downs should balance out, like heads and tails, and the p-value comes straight from a binomial distribution. Because it uses so little information, it's less powerful than Wilcoxon, but it makes almost no assumptions. Enter the two paired series.
Heads or tails to decide whether something changed
Of all the paired tests, the sign test is the most stripped down. It throws away the magnitude of the differences and keeps only the direction: did the value go up or down? That deliberate renunciation of information is also its strength, because it makes the test valid with practically no assumption about the shape of the data, requiring only that the observations be independent.
The logic is that of a fair coin. If the treatment changes nothing, each pair is equally likely to go up or down, and the number of increases follows a binomial distribution with probability one-half. A number of increases far from half is unlikely by chance, and it is precisely that unlikelihood that the binomial p-value quantifies, with no approximations needed.
Enter the two paired series. The tool counts how many differences were positive and negative, drops the ties and computes the exact two-sided p-value from the binomial. Keep in mind: because it uses so little information, the sign test has less power than Wilcoxon, so prefer it when you genuinely don't trust the magnitude of the measurements, only their direction.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.