Post hoc analysis

Post hoc analysis is a statistical methodology used to compare the results of one or more experiments. It involves re-examining data that has already been collected and analyzing any relationships between variables that were not explored in the initial analysis. This helps to further understand the experiment, identify any missed opportunities, and draw more meaningful conclusions. For managers, post hoc analysis can be used to gain a better understanding of the results of their experiment, allowing them to make more informed decisions and improve their strategies.

Example of post hoc analysis

• Post hoc analysis can be used to identify any missed opportunities in a marketing campaign. For example, if a company launched a new product in a certain market but failed to achieve the desired results, a post hoc analysis can be performed to identify any underlying factors that might have contributed to the failure. This could include analyzing the demographics of the target market, the effectiveness of the ad campaign, or any other factors that could have impacted the success of the product launch. By understanding the underlying factors, the company can make more informed decisions about their future marketing strategies.
• Post hoc analysis can also be used to assess the effectiveness of an employee training program. After the training has been completed, a post hoc analysis can be used to evaluate the results and identify any areas where the program could have been improved. This could include comparing the performance of employees before and after the program, analyzing the feedback from the participants, and assessing the overall impact of the training on the company's performance. The insights gained from the post hoc analysis can be used to refine the program and ensure that it is as effective as possible in the future.

When to use post hoc analysis

Post hoc analysis can be used in a variety of situations, including:

• Analyzing the results of a split test, to determine which version was more effective and why;
• Investigating the effects of changes in pricing or marketing campaigns on customer behavior;
• Examining the results of different product launches to identify successes and failures;
• Identifying correlations between different variables and predict future outcomes;
• Investigating the effects of changes in policies and procedures on employee performance;
• Comparing the results of different experiments to identify significant differences and trends;
• Identifying key drivers of success or failure in a given situation.

Types of post hoc analysis

Post hoc analysis is a statistical method used to examine the data from experiments after they have been collected. It allows researchers and managers to gain a better understanding of their results and draw more meaningful conclusions. There are several types of post hoc analysis, including:

• Bonferroni Correction: This technique is used to adjust the significance level of an experiment, allowing for multiple comparisons to be made within the same results.
• Fisher’s Least Significant Difference (LSD): This technique is used to compare the means of two or more groups in an experiment and determine which differences are statistically significant.
• Tukey’s Range Test: This technique is used to compare the means of three or more groups in an experiment and determine which differences are statistically significant.
• Scheffe’s Test: This technique is used to compare the means of three or more groups in an experiment and determine which differences are statistically significant.
• Chi-Square Test: This technique is used to compare the frequencies of two or more groups in an experiment and determine which differences are statistically significant.

Overall, post hoc analysis can provide researchers and managers with valuable insights into the results of their experiments. By using these techniques, researchers can make more accurate conclusions and managers can make more informed decisions.

Steps of post hoc analysis

Post hoc analysis involves several steps to ensure accuracy and thoroughness of the data analysis. These steps include:

• Identifying the hypothesis and objectives of the experiment: This helps to determine the data that should be collected and analyzed.
• Collecting data: This includes gathering all data related to the experiment and organizing it into an easy-to-understand format.
• Analyzing data: This involves examining the data to uncover any relationships between variables that were not explored in the initial analysis.
• Interpreting results: This allows the researcher to draw meaningful conclusions from the data and make decisions about the experiment.
• Documenting findings: This allows the researcher to track their progress and revisit the results in the future.

Advantages of post hoc analysis

Post hoc analysis has many advantages that make it a valuable tool for managers. These advantages include:

• Increased Understanding: Post hoc analysis helps to identify any relationships between variables that were not explored in the initial analysis, allowing managers to gain a better understanding of the results of their experiment.
• Improved Strategies: By identifying missed opportunities, post hoc analysis can help managers to improve their strategies and make more informed decisions.
• More Meaningful Conclusions: Post hoc analysis helps to draw more meaningful conclusions from the data that has already been collected, allowing managers to get the most out of their experiments.

Limitations of post hoc analysis

Post hoc analysis can be a useful tool for understanding experiment results and making more informed decisions. However, it is important to remember that post hoc analysis has its limitations. These include:

• Time constraints: Post hoc analysis requires going back and re-examining the data already collected, which can be time-consuming and put a strain on resources.
• Limited data: Post hoc analysis relies on the data that was collected in the initial experiment, so any data that was not collected cannot be used for further analysis.
• Potential bias: Post hoc analysis involves re-examining data that has already been collected, which can lead to bias or incorrect conclusions.
• Limited ability to adjust: Post hoc analysis does not allow for adjustments or changes to the experiment, so any changes that need to be made must be done in a new experiment.

Other approaches related to post hoc analysis

Post hoc analysis is an important method used to examine the results of experiments. Other related approaches include:

• Exploratory data analysis (EDA): This technique is used to explore and analyze data in order to gain insights and draw meaningful conclusions. It involves using graphical and statistical methods to identify patterns and relationships in the data that can be used to inform decision-making.
• Confirmatory data analysis (CDA): This technique is used to test hypotheses that are formed in advance. It involves using statistical methods to confirm or refute these hypotheses and draw valid conclusions.
• Predictive analytics: This technique is used to forecast future outcomes based on past data. It involves using statistical and machine learning methods to identify patterns and trends in the data that can be used to predict future outcomes.

Overall, post hoc analysis is an important tool for exploring the results of experiments and drawing meaningful conclusions. It can be used in conjunction with other approaches such as exploratory data analysis, confirmatory data analysis, and predictive analytics to gain a better understanding of the data and make more informed decisions.

Post hoc analysis — recommended articles

Analysis of information — Analysis and interpretation — Case study analysis — Mapping knowledge — Quantitative market research — Negative correlation — Data collection methods — Data and information — Statistical methods

References

• Shan, G., & Gerstenberger, S. (2017). Fisher’s exact approach for post hoc analysis of a chi-squared test. PloS one, 12(12), e0188709.