What does the null hypothesis assume?

What does the null hypothesis assume?

• A. There is an effect or difference
• B. There is no effect or difference
• C. The effect is due to bias
• D. The result is always significant

Answer: (B)

The null hypothesis is a statement that there is no effect or no difference. It provides a baseline assumption for testing, representing what we would expect to see if nothing unusual is happening. When we collect data, we check whether the observed results are unlikely under this no-effect assumption. If they are very unlikely (p-value below the chosen threshold), we reject the null and infer an effect or difference. If they aren’t unlikely enough, we fail to reject the null, meaning the data don’t provide strong evidence of an effect given the sample and variability. So, in this question, the null hypothesis assumes no effect or difference. The other ideas describe scenarios involving an effect, bias, or universal significance, which aren’t what the null statement asserts.

The null hypothesis is a statement that there is no effect or no difference. It provides a baseline assumption for testing, representing what we would expect to see if nothing unusual is happening. When we collect data, we check whether the observed results are unlikely under this no-effect assumption. If they are very unlikely (p-value below the chosen threshold), we reject the null and infer an effect or difference. If they aren’t unlikely enough, we fail to reject the null, meaning the data don’t provide strong evidence of an effect given the sample and variability. So, in this question, the null hypothesis assumes no effect or difference. The other ideas describe scenarios involving an effect, bias, or universal significance, which aren’t what the null statement asserts.