What does the term statistically significant mean?
Statistically significant simply means that an outcome had a low probability of occurring simply due to chance. For example, if I tell you that I can flip a fair coin and make it land on heads whenever I want, you would demand proof. If I flipped the coin one time and it landed on heads, would you be impressed? Of course not (I hope)! The probability of such an event occurring is too high. How about two times in a row? Nope, still to high. However, there is going to be a point where you stay, Stop, Im convinced. How many times I flip the coin in order to be convincing is up to the individual. Some people might demand I do it 5 times, while others might demand as many as 10 or more. In statistics, however, we cant afford to be so arbitrary. Convention has set the statistical significance level at .05 or 5%. This is known as our alpha level , which is simply the level at which point we say something is statistically significant or unlikely to occur simply due to chance. How unlikely is u
