# statistical test for discrete data

If the data is normally distributed, use the independent t-test, if not use the Mann-Whitney test. Wilcoxon t-test: A non-parametric statistical hypothesis test used when comparing two related samples, matched samples, or repeated measurements on a single sample to assess whether their population mean ranks differ (i.e., it is a paired-difference test). Basically we use two types of data in our statistical analysis: 1.Discrete Data 2.Continuous Data Below table illustrates how data type determines which statistical test can be applied in a given scenario. For example, if Y (dependent variable) is continuous and Xs (independent variables) are discrete then we can use ANOVA to test means. tie: One or more equal values or sets of equal values in the data … Commonly, this refers to data that can be counted with whole numbers, such as the data on test scores we saw in a previous lesson. This test compares 2 independent populations to determine whether they are different. Discrete data refers to variables which can only take a specific, clearly defined set of values. In order to test the hypothesis, we measure the discrete outcome variable in each participant in each comparison group. Qualitative Data Tests. Hi everyone, I have very little background in statistics (mainly intro courses and some basic statistics for life sciences courses) and am working with a project right now where we have implemented a program in a health organization and are looking at a count of hospitalizations prior- and post-implementation of … One of the most common statistical tests for qualitative data is the chi-square test (both the goodness of fit test and test of independence). oth ‘Treatment’ (A or ) and ‘Recovery’ (Yes or No) are categorical variables so the hi-squared test is appropriate. The data of interest are the observed frequencies (or number of participants in each response category in each group). Quick review of discrete probability distributions: binomial, multinomial, and Poisson. Poisson data are a count of the presence of a characteristic, result, or activity over a constant amount of time, area, or other length of observation. Implementing tests for one-way tables using Pearsons X2 and likelihood-ratio G2 statistics. Once the 2 test statistics are calculated, the smaller one is used to determine signiﬁcance. An introduction to the concept of likelihood. Poisson Hypothesis Tests for Count Data. In statistics, we often model count data using the Poisson distribution. continuous variable but can be used for ordinal data. Are patients taking treatment A more likely to recover than those on treatment B? The formula for the test statistic for the χ 2 test of independence is given below. However, it is also possible for non-numeric data to be discrete as well. The sample values from both sets of data are ranked together. Therefore, many statistical tests can be conveniently performed as approximate z-tests if the sample size is large or the population variance known. Count data can have only non-negative integers (e.g., 0, 1, 2, etc.).