A Beginner’s Guide to Choosing the Right Statistical Test in Machine Learning Modeling

Yennhi95zz
4 min readMar 27, 2023

Machine learning modeling involves using statistical tests to make predictions based on data. As a beginner, it can be overwhelming to choose the right statistical test for your model. This blog post aims to provide a beginner’s guide to choosing the right statistical test in machine learning modeling.

Step 1: Identify the Type of Data

The first step in choosing the right statistical test is to identify the type of data. There are two types of data: categorical and continuous.

Categorical data refers to data that can be placed into specific categories or groups, such as gender or race. Continuous data refers to data that can take any value, such as height or weight.

Python Code:

To identify the type of data, we can use the dtype attribute in Pandas:

import pandas as pd
data = pd.read_csv('data.csv')
print(data.dtypes)

Step 2: Determine the Goal of the Analysis

The next step is to determine the goal of the analysis. Are you trying to compare groups or test for a relationship between variables? Depending on the goal, different statistical tests will be appropriate.

Examples:

  • If you want to compare the mean of two groups, use a t-test.
  • If you want to compare the mean of more than two groups, use ANOVA.
  • If you want to test for a relationship between two variables, use a correlation test.

Python Code:

To perform a t-test in Python, we can use the ttest_ind function in Scipy:

from scipy.stats import ttest_ind
group1 = data[data['group'] == 'A']['value']
group2 = data[data['group'] == 'B']['value']
t, p = ttest_ind(group1, group2)
print("t =", t, "p =", p)

Step 3: Check Assumptions

Before using a statistical test, it is important to check assumptions. Different statistical tests have different assumptions, such as normality and homogeneity of variance. Violations of assumptions can affect the validity of the results.

Python Code:

To check for normality, we can use the Shapiro-Wilk test in Scipy:

from scipy.stats import shapiro
stat, p = shapiro(data['value'])
print("stat =", stat, "p =", p)

Step 4: Choose the Statistical Test

Once you have identified the type of data, determined the goal of the analysis, and checked assumptions, you can choose the appropriate statistical test.

To choose the appropriate statistical test, we can use the following flowchart:

Choosing a Statistical Test — Credit: Scribbr

Step 5: Interpret the Results

After performing the statistical test, it is important to interpret the results. Depending on the test, you may need to look at the p-value, confidence intervals, effect size, or other measures.

Recommendations

  • Always check assumptions before using a statistical test.
  • Use the appropriate statistical test based on the type of data and goal of the analysis.
  • Interpret the results carefully and in the context of the research question.

Conclusion

Choosing the right statistical test is an important step in machine learning modeling. By following the steps outlined in this blog post, beginners can choose the appropriate statistical test and interpret the results with confidence.

Remember to always check assumptions and choose the appropriate statistical test based on the type of data and goal of the analysis. With the right statistical test, you can make accurate predictions and draw meaningful conclusions from your data.

It’s also important to note that statistical tests are just one part of the machine learning modeling process. Other important steps include data cleaning, feature engineering, model selection, and model evaluation. Therefore, it’s important to have a well-rounded understanding of the entire modeling process and not just the statistical tests.

In addition, there are many resources available online to help you choose the right statistical test for your analysis. Some popular statistical software packages include Python libraries such as NumPy, Pandas, Scipy, and Scikit-learn, as well as R packages such as dplyr, ggplot2, and caret. These resources can provide helpful tutorials, examples, and documentation to guide you in your statistical analysis.

In conclusion, choosing the right statistical test is an important step in machine learning modeling. By following the steps outlined in this blog post and utilizing available resources, you can ensure that your statistical analysis is accurate, reliable, and meaningful.

References

  1. “Choosing the Right Statistical Test for Data Analysis”: This article provides an overview of common statistical tests and their appropriate uses in data analysis. https://www.scribbr.com/statistics/statistical-tests/
  2. “Statistical Analysis in Python”: This tutorial provides an introduction to statistical analysis in Python, including a discussion of statistical tests and their implementation in Python libraries. https://realpython.com/python-statistics/
  3. “A Beginner’s Guide to Statistical Analysis and Data Modeling in Python”: This guide provides an overview of statistical analysis and data modeling in Python, including an introduction to statistical tests and their use in Python libraries. https://www.dataquest.io/blog/statistical-analysis-python/
  4. “Choosing the Right Statistical Test for Your Data Analysis”: This guide provides a detailed explanation of how to choose the appropriate statistical test for a given analysis, including a helpful flowchart. https://www.statisticssolutions.com/choosing-the-right-statistical-test-for-your-data-analysis/
  5. “Introduction to Statistical Tests in Python”: This tutorial provides an introduction to statistical tests in Python, including a discussion of how to select the appropriate test based on data type and research question. https://towardsdatascience.com/introduction-to-statistical-tests-in-python-40f16b9e4f41

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