A quick review of steps for the 1-way between subjects ANOVA

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Background | Enter Data | Analyze Data | Interpret Data | Report Data

I Enter your data into two columns in the data file

 

  1. Use the first column of the data file to enter each of the three IV conditions of your experiment. You can use the numbers 1, 2 and three to represent each condition. If you have four conditions, enter 1,2,3 and 4 representing each condition.
  2. Give the first column a meaningful name. This name should help you to know that you are looking at various conditions of the IV.
  3. In the Define Variable Box, click Labels to label your conditions. Give each condition number a meaningful name. This will help you to interpret your data in the future.
  4. Use the second column of the data file to enter your data collected from each of the conditions. Type all of your condition 1 data points to the right of each condition 1 label listed in the first column.  Continue on until you have entered the data for all of your conditions.
  5. Give the second column a meaningful name. This name should help you to know that you are looking at the DV data or what was measured in your experience.
  6. Save the data file to a meaningful place with a meaningful name. This file should have a .sav extension.

II. Analyze your data

 

  1. Click Analyze, Compare Means and then One-Way ANOVA. A One-Way ANOVA box will appear.
  2. Click on the IV to highlight it. Transfer the IV to the factor box by clicking on the corresponding arrow.
  3. Click on the DV to highlight it. Transfer the DV to the Dependent List box by clicking on the corresponding arrow.
  4. Click the Options button. A One-Way ANOVA Options box will appear.
  5. Check the Descriptives and Homogeneity of Variance Boxes. Then Click Continue. You will return to the One-Way ANOVA box.
  6. Click the Post Hoc Button. A One-Way ANOVA: Post Hoc Multiple Comparisons box will appear. Check the post hoc test that you are interested in conducting. In this book, we focused on the Tukey post hoc test.
  7. Click the Continue button. You will return to the One-Way ANOVA box.
  8. Click the OK button and wait a few seconds for processing.
  9. You will see your results. Save the results to a meaningful place with a meaningful name. SPSS should give the output file a .spo extension.

 

III. Interpret your results

 

  1. Look in the Descriptive Statistics box for condition means, standard deviations and number of participants.
  2. Make sure the number of participants for each condition is accurate. If it is not, go back to the data file and make sure it is correct.
  3. Look in the ANOVA box.
  4. Check the Sig value in the last column. If the Sig value is greater than .05, you can conclude that there is no statistically significant difference between your conditions – that the IV did not have a significant effect on the DV. However, if the Sig value is less than or equal to .05, you can conclude that there is a statistically significant difference between some or all of your conditions. This means that it is likely that the IV did have an effect on the DV and the results were not likely due to chance.
  5. If the Sig. value is less than or equal to .05, you will need to look at the output for your Post hoc test to compare each condition to every other condition. To do this, Look at the Multiple Comparisons box. Check the Sig. Values for each comparison of conditions to find out which conditions are significantly different from one another. Like before, if the Sig value is greater than .05, you can conclude that there is no statistically significant difference between your conditions – that the IV did not have a significant effect on the DV. However, if the Sig value is less than or equal to .05, you can conclude that there is a statistically significant difference between some or all of your conditions. This means that it is likely that the IV did have an effect on the DV and the results were not likely due to chance.

 

IV. Report your results

 

  1. Report the type of test used and what it was used to test.
  2. Report whether or not there was a significant difference between your conditions. Include the group means, standard deviation, and the Sig. values.
  3. If there was a significant difference between your conditions as determined by the 1-Way ANOVA, report the results of the post hoc test that you conducted.
  4. Report your results in words that people can understand.

Background | Enter Data | Analyze Data | Interpret Data | Report Data

 

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