Search results
Results from the WOW.Com Content Network
The example above is the simplest kind of contingency table, a table in which each variable has only two levels; this is called a 2 × 2 contingency table. In principle, any number of rows and columns may be used. There may also be more than two variables, but higher order contingency tables are difficult to represent visually.
This formula is chiefly used when at least one cell of the table has an expected count smaller than 5. ∑ i = 1 N O i = 20 {\displaystyle \sum _{i=1}^{N}O_{i}=20\,} The following is Yates's corrected version of Pearson's chi-squared statistics :
Chi-squared distribution, showing χ 2 on the x-axis and p-value (right tail probability) on the y-axis. A chi-squared test (also chi-square or χ 2 test) is a statistical hypothesis test used in the analysis of contingency tables when the sample sizes are large.
Fisher's exact test is a statistical significance test used in the analysis of contingency tables. [1] [2] [3] Although in practice it is employed when sample sizes are small, it is valid for all sample sizes.
Download as PDF; Printable version; ... Timeline of probability and statistics; List of unsolved problems in statistics; Probability
Four bits of information determine all the entries in the contingency table, including its marginal totals. For example, if we know H, M, F, and C, then we can compute all the marginal totals for any threshold. Alternatively, if we know H/P, F/Q, P, and Q, then we can compute all the entries in the table. [1]
The sample data is a random sampling from a fixed distribution or population where every collection of members of the population of the given sample size has an equal probability of selection. Variants of the test have been developed for complex samples, such as where the data is weighted.
An example of Pearson's test is a comparison of two coins to determine whether they have the same probability of coming up heads. The observations can be put into a contingency table with rows corresponding to the coin and columns corresponding to heads or tails. The elements of the contingency table will be the number of times each coin came ...