Revise later
SpaceTo flip
If confident
All Flashcards
Explain the concept of a p-value in the context of a Chi-Square test.
The probability of observing a χ² statistic as extreme as the one calculated, assuming H₀ is true. A low p-value leads to rejecting H₀.
Explain what a large χ² value suggests.
A large χ² value suggests that the expected counts are not accurate, leading to rejection of H₀.
Explain the importance of context in the conclusion of a Chi-Square test.
Always relate your findings back to the original problem to provide a meaningful interpretation of the results.
Explain what failing to reject the null hypothesis means.
It means there is not convincing evidence for the alternative hypothesis. We do not 'accept' the null hypothesis.
Explain what rejecting the null hypothesis means.
It means there is convincing evidence for the alternative hypothesis.
What is the Chi-Square Goodness of Fit Test?
A test to determine if an observed frequency distribution matches a theoretical expected distribution.
What is the Null Hypothesis (H₀) in a Chi-Square test?
The observed distribution is the same as the expected distribution.
What is the Alternative Hypothesis (Hₐ) in a Chi-Square test?
The observed and expected distributions are significantly different.
What is the significance level (α)?
The threshold for rejecting the null hypothesis (H₀).
What are degrees of freedom (df) in a Chi-Square test?
Number of categories - 1.
What is the formula for the Chi-Square statistic (χ²)?
$\chi^2 = \sum \frac{(Observed - Expected)^2}{Expected}$
How do you calculate expected frequencies?
Expected Frequency = (Probability of category) * (Total number of observations)
How to calculate degrees of freedom (df)?
df = Number of categories - 1