I've been reading about statistical significance and I am confused about one thing.
Say I have 100 control group and 100 experimental group(drug received). I've gathered result of test and want to conclude that there is difference btwn two groups => drug is effective.
We must start by creating null hypothesis
Ho = two groups are the same.
Ha = two groups are NOT the same.
our goal is to reject the null hypothesis to conclude that Ha is true.
To reject null hypothesis p < alpha = 0.05. To calculate p value we calculate z-score of Xi (each person in exp group) and then find their p-values.
Here is what I'm confused about --> so we get p-value for each individual and if its p-value < 0.05 then we say that one person's result is statistically significant? and do the same for rest 99 people and if more than 95 people's results are statistically significant we say from our experiment we can conclude that drug is effective with 95% confidence?
Another Q: Why not simply try to prove that Ha is true? instead of rejecting Ho?
Thanks in advance!