How do you interpret a p-value?
Channel: YouTooBio
Date: 13/04/2021

What is a p-value and why is it so special if it’s less than 0.05? This video describes how scientists use p-values to decide if the difference between two data sets is real, or just due to random chance. Bonus: learn about cool research about how the bacteria in your gut might affect how much you weigh!

0:00 Introduction
0:18 Example from research: Mouse microbiome and obesity
1:10 Are the data sets really different?
2:23 What p-values help us do
3:13 Null Hypothesis and Alternative Hypothesis
3:37 Warning: Null & Alternative Hypotheses do not equal Scientific Hypothesis
4:08 What is a p-value?
5:46 Why is p less than 0.05 so special?
8:47 Does the microbiome of obese mice contribute to obesity?

The research study about the obesity and the microbiome in mice is:

P. J. Turnbaugh, et al., An obesity-associated gut microbiome with increased capacity for energy harvest. Nature 444, 1027–1031 (2006). https://doi.org/10.1038/nature05414

Scientific Consultation by Malcolm Campbell
Cartoon Illustrations by Michelle Lotker

p-value examples that pop up in the first 10 seconds are from these papers:

X. Ding, Z. Yang, Y. Han, H. Yu, Fatty Acid Oxidation Changes and the Correlation with Oxidative Stress in Different Preeclampsia-Like Mouse Models. PLOS ONE 9, e109554 (2014).
M. P. Mullen, J. P. Hanrahan, Direct Evidence on the Contribution of a Missense Mutation in GDF9 to Variation in Ovulation Rate of Finnsheep. PLOS ONE 9, e95251 (2014).
N. P. Ward, A. M. Poff, A. P. Koutnik, D. P. D’Agostino, Complex I inhibition augments dichloroacetate cytotoxicity through enhancing oxidative stress in VM-M3 glioblastoma cells. PLOS ONE 12, e0180061 (2017).

This video is copyright Jayme Dyer, published under the Creative Commons CC-BY SA 4.0 license. 

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