Description	One Sample Wilcoxon Signed Rank Test is a non-parametric version of a one-sample t-test. It is used to determine if the median of the sample value is equal to the known standard or theoretical value.
Why to use	To determine if a single group differs significantly from a known or a hypothesized value.
When to use	When the variable is continuous. When there is one group.	When not to use	You have non-continuous variables. When variables are non-numeric.
Prerequisites	Variables must be continuous. Variable is a random sample from the population.
Input	Numeric dataset	Output	Population median p Value Test statistic
Statistical Methods Used	Median Alpha (α)	Limitations	If the values of many data entries are the same, the test may produce incorrect results.

One Sample Wilcoxon Signed Rank Test is located under Model Studio () in Statistical Analysis below Hypothesis Test, under Non-Parametric Test in the left task pane. Use the drag-and-drop method or double-click to use the algorithm in the canvas. Click the algorithm to view and select different properties for analysis. You can access it using the search option.

The system calculates the p value in this test and compares it with the alpha value.

Criteria	Interpretation
When the p-value is greater than alpha an alternative hypothesis can either be "Two-sided" or "One-sided (less than)" or "One-sided (greater than)".	As the p-value is greater than alpha, the population median does not differ from the hypothesized median.
When the p-value is less than or equal to alpha and the alternative hypothesis is equal to" Two-sided".	As the p-value is less than or equal to alpha, the population median differs from the hypothesized median.
When the p-value is less than equal to alpha and the alternative hypothesis is equal to "One-sided(less than)".	As the p-value is less than or equal to alpha, the population median is less than the hypothesized median.
When the p-value is less than equal to alpha and the alternative hypothesis is equal to "One-sided (greater than)".	As the p-value is less than or equal to alpha, the population median is greater than the population median hypothesized median.

Properties of One Sample Wilcoxon Signed Rank Test

The available properties of the One Sample Wilcoxon Signed Rank Test are shown below.

The table below describes the different properties of the One Sample Wilcoxon Signed Rank Test.

Field		Description	Remark
Task Name		It is the name of the task selected on the workbook canvas.	You can click the text field to edit or modify the task's name. Space between words is not allowed in the Task Name.
Features		It allows you to select the independent variable.	You need to select numeric data. Only columns with numeric data will be shown.
Advanced	Hypothesized mean	It is the value that the test uses to determine if the group differs	The default value is 5. You can modify this value.
	Zero Method	Zero difference is a way of telling whether you wish to discard the differences in your data or not.	For Zero difference, you can choose from 3 available methods. Wilcox – It discards all zero differences. Pratt – It includes the zero differences in the ranking process but drops the ranks of the zeros. For Pratt, the dataset must ideally have more than 20 data points. Zsplit – It includes zero differences in the ranking process and splits the zero rank between positive and negative. The method selected by default is Wilcox.
	Correction	If true, it means that we are applying the continuity correction. We adjust the Wilcoxon rank statistic by 0.5 towards the mean value. We do this while computing the z statistic.	The default value is False. You can modify this value. If the correction is True, Continuity is applied and a normal approximation is used. This is done by adjusting the Wilcoxon rank statistic. This is done while computing the z-statistic in the case where a normal approximation is used.
	Alpha	It allows you to set the level of significance.	The default value is 0.05. You can modify this value. The value of alpha lies between 0 and 1. The value 0 interprets 100% confidence on the test. The value 1 interprets 0% confidence on the test. The system cannot guarantee both scenarios; hence the values cannot be 0 and 1.
	Alternative	Defines the alternative hypothesis.	The default value is Two-sided. You can modify this value. You can choose from – Two-sided - the distributions are not equal Larger- underlying x distribution is stochastically less than the underlying y distribution. Smaller- underlying x distribution is stochastically greater than the underlying y distribution.
Node Configuration		It allows you to select the instance of the AWS server to provide control over the execution of a task in a workbook or workflow.	For more details, refer to Worker Node Configuration.

Example of One Wilcoxon Signed Rank Test

As a medical researcher, you would like to know if a given Drug 1 performs better than the determined level of 5. You use one sample Wilcoxon test to do so.

The data tab shows the selected input column and a new column called Difference which shows the values obtained after subtracting the hypothesized median, which is 5 in this case, from the input column.
Further, the Result page is as follows.

The result page consists of the following sections:

Hypothesis:
This section displays Null Hypothesis and Alternative Hypothesis defined by the system.
One Sample Wilcoxon Signed Rank Test:
This section displays the One-Sample Wilcoxon Signed Rank test result. It shows a value of the following parameters:
- Population Median
- Hypothesized Median
- Test Statistic
- p Value
- Alpha (α)
Interpretation:
In this example, the p value (0.0001) is less than the alpha value (0.05); hence the null hypothesis is rejected. Thus, in this case, the level of effectiveness of drug 1 is more than 5.

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