Think about Power and how it is the probability of finding an effect when one truly exists. We want high power. One manageable way to increase power is to increase sample size. On the other hand, you can have a huge sample and find significance, but the treatment effect (difference) is very small so it would not usually be considered 'practical'. For example, Education Agencies will not implement a reading program if it only increases scores by 0.1 points (could be significant but not practical).

Find an interesting Statistics statement that you have read recently in the news or in your research. Find a statement where they found an significant 'effect' in the analysis. Discuss whether you feel if it is of practical significance, that is, if the difference is substantial enough to implement the treatment.

For instance, eating less carbs might help a person lose weight. However if the new diet only affects a person by 1 pound, that may not be considered practical significance though it may have been significant in the hypothesis test. Having enough sample size can make any difference, even a REALLY small one, significant.