What does "t Score" mean?
Definition of t Score in the context of A/B testing (online controlled experiments).
What is a t Score?
A t Score or a t-statistic is the result of applying a T-test and it represents a point from a Student's T-distribution with n-k degrees of freedom where n is the total sample size and k is the number of test groups in an A/B test. A t score is often not communicated directly but is first transformed into a p-value by calculating the cumulative distribution function of the relevant T-distribution.
A t score is rarely used in A/B testing since it is only needed when the population standard deviation is unknown and the sample size is smaller than 30. In all other cases the z score and the t score[/t] are identical for most practical purposes.
Like this glossary entry? For an in-depth and comprehensive reading on A/B testing stats, check out the book "Statistical Methods in Online A/B Testing" by the author of this glossary, Georgi Georgiev.
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Standard DeviationT-testz ScoreAbout the author
Georgi has over twenty years of experience in online marketing, web analytics, statistics, and design of business experiments.
Author of the book "Statistical Methods in Online A/B Testing", white papers on statistical analysis of A/B tests, and a speaker, he has been distinguished as a winner in the Data & Analytics category of the 2024 Experimentation Thought Leadership Awards.
Statistical Methods in Online A/B Testing
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