Terms_and_Definitions Flashcards
A/B Test
A method of comparing two versions of a webpage, feature, or app against each other to determine which performs better.
Null Hypothesis (H₀)
Assumes there is no significant difference between the control and test groups.
Alternative Hypothesis (H₁)
Assumes there is a significant difference between the control and test groups.
P-Value
The probability of observing results at least as extreme as those measured, assuming the null hypothesis is true.
Significance Level (α)
The threshold for rejecting the null hypothesis (commonly set at 0.05).
Confidence Interval (CI)
A range of values that is likely to contain the true effect size or metric with a given level of confidence (e.g., 95%).
Control Group
The group that does not receive the treatment or variant being tested.
Test Group
The group that receives the treatment or variant being tested.
Randomization
Assigning participants to groups in a way that each participant has an equal chance of being in any group.
Power Analysis
A calculation to determine the minimum sample size required to detect a given effect size with sufficient power.
Effect Size
The magnitude of the difference between groups (e.g., a 5% increase in conversion rate).
Type I Error
Incorrectly rejecting the null hypothesis (false positive).
Type II Error
Failing to reject the null hypothesis when it is false (false negative).
Bonferroni Correction
A method to adjust significance levels when multiple comparisons are being made.
Simpson’s Paradox
A trend appears in different groups of data but disappears or reverses when the groups are combined.
Descriptive Statistics
Summarizing and describing the features of a dataset (e.g., mean, median, mode).
Inferential Statistics
Using a sample to make generalizations about a population (e.g., hypothesis testing, confidence intervals).
Mean
The average value of a dataset.
Median
The middle value in a dataset when ordered.
Mode
The most frequently occurring value in a dataset.
Variance
A measure of how much values in a dataset vary from the mean.
Standard Deviation
The square root of the variance, representing data dispersion.
Z-Test
A hypothesis test for comparing means when the population variance is known.
T-Test
A hypothesis test for comparing means when the population variance is unknown.
ANOVA (Analysis of Variance)
A test to compare the means of three or more groups.
Chi-Square Test
A test for relationships between categorical variables.