Strong research is built on sound methodology—and in academic writing, nothing weakens a thesis faster than statistical errors. Whether you’re a graduate student or early-career researcher, understanding the common statistical errors in thesis writing can help you avoid critical pitfalls that compromise your credibility. This guide outlines the top biostatistics mistakes to avoid and offers practical ways to correct them.
Using the Wrong Statistical Test
Choosing an inappropriate statistical test is one of the most common statistical errors in thesis writing. Many students apply tests without checking assumptions like normality, independence, or homogeneity of variance.
How to Fix It:
Consult a biostatistician or use decision trees to select tests based on your data type and hypothesis. Tools like SPSS, R, and JASP can guide you through assumptions checks.
Small or Inadequate Sample Size
Underpowered studies due to small sample sizes can lead to misleading results. This is a major research methodology pitfall that affects both reliability and significance.
How to Fix It:
Conduct a power analysis before data collection to determine the minimum required sample size. This reduces Type II errors and improves result validity.
Misinterpreting p-values
A p-value below 0.05 is often misinterpreted as “proof” that the hypothesis is true. This is a frequent biostatistics mistake to avoid in thesis and dissertation writing.
How to Fix It:
Understand that p-values only indicate the likelihood of observing your data under the null hypothesis—not the magnitude or practical importance of an effect. Always report confidence intervals alongside p-values.
Failing to Check Assumptions
Skipping assumption tests like normality, linearity, and homoscedasticity can lead to invalid inferences from your data.
How to Fix It:
Run diagnostics (e.g., Shapiro-Wilk, Levene’s Test) before using parametric methods. If assumptions are violated, switch to non-parametric alternatives or transform your data appropriately.
Overuse of Descriptive Statistics
Descriptive statistics alone don’t support hypothesis testing or predictive modeling. Many students stop at means, medians, and percentages.
How to Fix It:
Go beyond basic summaries—apply inferential statistics to test relationships, compare groups, or build models based on your research questions.
Improper Data Cleaning and Coding
Errors during data entry, inconsistent coding, and missing data handling can lead to flawed analyses. These are avoidable yet common thesis writing errors.
How to Fix It:
Use data-cleaning protocols before analysis. Label variables clearly in SPSS or Excel, and use consistent coding (e.g., 0 = No, 1 = Yes). Document all data transformations for transparency.
Ignoring Effect Sizes and Practical Significance
Focusing only on statistical significance while ignoring effect size and context limits the real-world impact of your findings.
How to Fix It:
Always report effect sizes (e.g., Cohen’s d, odds ratios) along with p-values. This shows the practical relevance of your findings in real settings.
Final Thoughts: Avoiding Biostatistics Blunders
Understanding these biostatistics mistakes to avoid can dramatically improve the quality of your academic work. From flawed methodology to incorrect interpretation, statistical missteps can undermine even the best research ideas.
Need expert help to get it right? At Thesis Writing Cafe, we specialize in:
- Statistical test selection
- Sample size estimation
- Data cleaning and SPSS analysis
- Comprehensive thesis review and editing
Don’t let preventable errors ruin your hard work.
Visit Thesis Writing Cafe for personalized support on research methodology and statistical analysis.



