Question

Explain the difference between a statistically significant result and a large or “impressive” effect?

Answer 1

Usually Statistically significant results are carried out using some statistical tests like normal, t.test etc and are usually checked using p.value. if p.value is less then 0.05 we reject our null hypothesis otherwise accept. There will be always a significant change ( Change can be small or of large magnitude also) in the data over time or between the two groups which are being compared.  

On the other hand if the change is of good strength or very large it will be significant obviously is called impressive.