Proportions: Sign test (binomial test)

The sign test is equivalent to a test that the probability π of an event in the populations has the value π₀ = 0.5. It is identical to the special case π₀ = 0.5 of the Proportion (binomial test): Difference from constant (one sample case) test. For a more thorough description see the comments for that test.

Effect size index

The effect size index is g = π − 0.5.
Cohen (1969, p. 142) defined the following effect size conventions:

small g = 0.05
medium g = 0.15
large g = 0.25 .

Options, examples, implementation note, and validation

See comments for Proportion (binomial test): Difference from constant (one sample case)