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Type II error

the error of failing to reject the null hypothesis when it is in fact not true. Investigators make this error if they conclude that a particular effect or relationship does not exist when in fact it does. The probability of committing a Type II error is called the beta (β) level of a test. Conversely, the probability of not committing a Type II error (i.e., of detecting a genuinely significant difference between samples) is called the power of the test, where power = 1 – β. Also called beta error.

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Psychology term of the day

November 23rd 2024

theoretical probability

theoretical probability

the mathematical likelihood of a particular event occurring, as determined by dividing the number of positive outcomes by the total number of possible outcomes. For example, when flipping a coin, the theoretical probability that a tail will occur is 1 divided by 2 (the number of possible outcomes), giving a probability of .5 or 50%.