How to do One-Way ANOVA in Excel

Use one-way ANOVA to test whether the means of at least three groups are different. Excel refers to this test as Single Factor ANOVA. This post is an excellent introduction to perform and interpreting a one-way ANOVA test even if Excel isn ’ t your primary statistical software package .
In my previous post, we looked at using Excel to perform t-tests, which compare two means at most .

One-way ANOVA is a hypothesis test that allows you to compare more group means. Like all hypothesis tests, one-way ANOVA uses sample data to make inferences about the properties of an integral population. In this mail, I provide bit-by-bit instructions for using Excel to perform individual agent ANOVA and how to interpret the results. importantly, I besides include links to many extra resources I ’ ve written. This auxiliary capacity presents clear explanations of relevant one-way ANOVA and F-test concepts that you won ’ metric ton find in Excel ’ mho documentation .
While this post focuses on using Excel to run a one-way ANOVA and interpreting the results, I ’ ve written a companion post that uses the same dataset to illustrate graphically how the F-test works. These are two useful posts to read in concert. Before proceeding, verify that Excel ’ sulfur Data Analysis ToolPak is installed with your copy of Excel. Click Data in Excel ’ s menu across the lead and look for Data Analysis in the Analyze section .
Excel menu with Data Analysis ToolPak. Excel menu with Data Analysis ToolPak.
If you don ’ deoxythymidine monophosphate see Data Analysis, you need to install it. My post about using Excel to perform t-tests shows how to install the Data Analysis ToolPak. It ’ s dislodge ! Related post : Use the F-Test to Assess Variances in Excel

One-Way ANOVA in Excel

one-way analysis of Variance ( ANOVA ) requires one categorical gene for the independent variable and a continuous variable for the dependant varying. The values of the categorical factor divide the continuous data into groups. The test determines whether the think of differences between these groups are statistically significant. For example, if fertilizer character is your categoric variable, you can determine whether the differences between plant emergence means for at least three fertilizers are statistically significant. While the means can differ between your groups, their variability should be roughly adequate to obtain valid results. Learn more about heterogeneity .
To perform one-way ANOVA in Excel, choose the option shown below. Screenshot of One Factor ANOVA highlighted in Excel. Screenshot of One Factor ANOVA highlighted in Excel.
technically, you can use one-way ANOVA to compare two groups. however, if you have two groups, you ’ ll typically use a two- sample t-test .
The standard hypotheses for one-way ANOVA are the come :

  • Null: All group means are equal.
  • Alternative: Not all group means are equal.

If the p-value is less than your significance degree ( normally 0.05 ), reject the nothing guess. Your sample distribution data patronize the hypothesis that the intend of at least one population is different from the early population means. Again, hypothesis tests use sample data to draw conclusions about populations .
To learn more about ANOVA tests, including the more building complex forms, read my ANOVA Overview .
For more information about the null and alternative hypotheses and other hypothesis testing terms, see my Hypothesis Testing Overview. besides, learn about the dispute between descriptive statistics and inferential statistics and learn more about interpreting p-values .

Step-by-Step Instructions for Running a One Factor ANOVA in Excel

Let ’ s conduct a one-way analysis of variance ! Our model scenario is that we are comparing the intensity of raw material from four suppliers. supplier is our categoric autonomous variable ( component ) while lastingness is the continuous dependent variable. We draw a random sample of 10 units of material from each supplier and measurement the force of all units. now, we want to determine whether the mean strengths of the material from the four suppliers are different .
To perform a one-way ANOVA in Excel, arrange your data in column, as shown below. For our example, each column represents raw material from one supplier. Download the CSV dataset for this exemplar : OneWayANOVAExcel .
Screenshot of data for one-way ANOVA. Screenshot of data for one-way ANOVA.
In Excel, do the surveil steps :

  1. Click Data Analysis on the Data tab.
  2. From the Data Analysis popup, choose Anova: Single Factor.
  3. Under Input, select the ranges for all columns of data.
  4. In Grouped By, choose Columns.
  5. Check the Labels checkbox if you have meaningful variables labels in row 1. This option helps make the output easier to interpret. Ensure that you include the label row in step #3.
  6. Excel uses a default Alpha value of 0.05, which is usually a good value. Alpha is the significance level. Change this value only when you have a specific reason for doing so.
  7. Click OK.

hera ’ s how the popup should look :
Image of Excel's one-way ANOVA popup for this example. Image of Excel's one-way ANOVA popup for this example.
After Excel creates the output signal, I autofit the width of column A to display all of the text in it .

Interpreting the One-Way ANOVA Results

Screen shot of Excel's one-way ANOVA output. Screen shot of Excel's one-way ANOVA output.
The Summary table indicates that the think of strengths range from a low of 8.837952 for supplier 4 to a high of 11.20252 for supplier 1. Our sample means are different. however, we need to determine whether our data confirm the notion that the population means are not equal. The differences we see in our samples might be the resultant role of random sampling error .
In the ANOVA table, the p-value is 0.031054. Because this value is less than our meaning degree of 0.05, we reject the nothing hypothesis. Our sample data provide strong adequate attest to conclude that the four population means are not equal .
For more information about the other statistics in the output, click the links for F-value and F critical respect, degrees of exemption ( df ), average ( mean ), variance, p-values, and meaning flush .

What Excel’s One Factor ANOVA Does Not Include

Using the same dataset, Excel ’ s one-way ANOVA results match those from my dedicate statistical software package, as you can see in my post about the F-test. That ’ south great ! however, Excel leaves out a peculiarly crucial feature—post hoc tests !
When using ANOVA, statistically significant results indicate that not all means are equal. however, ANOVA does not determine which means are different from the others. To make that determination, you need to perform post hoc tests, besides known as multiple comparisons. In Latin, post hoc means “ after this. ” You conduct post hoc analyses after obtaining statistically significant ANOVA results. For more information, read my station about Using Post Hoc Tests with ANOVA .
ultimately, lest we forget, ANOVA is a linear model, and we should check the remainder plots for problems. That ’ s not possible in excel !
The mention one-way ANOVA is based on the fact that this analysis requires one categoric factor. In my next military post, I cover two-factor, or two-way ANOVA, which is the other type of ANOVA that Excel includes.

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