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Index/Topics/Research Methodology

Research Methodology

The challenges and limitations of researching penis size and sexual satisfaction, including small sample sizes and measurement imprecision.

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Jan 13, 2026
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How is PSA doubling time calculated in clinical practice and which formula is recommended?

PSA doubling time (PSADT) is calculated by fitting an exponential (log-linear) model to serial PSA values and using PSADT = ln divided by the slope of ln(PSA) versus time; this log‑slope method is the...

Feb 7, 2026

How do studies measure penis size and what are the methodological limits of surveys on sexual satisfaction?

Scientific work on uses a patchwork of —self-report, stretched length, physician-measured erect length (sometimes pharmacologically induced), and novel proxies such as model selection or home kits—and...