CHOOSING THE ALTERNATE HYPOTHESIS

~The original claim may or may not be the null hypothesis

~It will be, if the original claim involves equality only. That is, a statement that the parameter being tested is equal to a certain value.

~If not, then the original claim will be the alternate hypothesis EXCEPT
in the following:

  a) The original claim contains the phrase "at least" or equivalent. In that case we take the negative for the alternate hypothesis. That would be "less than".  (< in symbolic form).

  b) The original claim contains the phrase "at most" or equivalent. In that case we take the negative for the alternate hypothesis. That would be "greater than". (> in symbolic form)

~Note: In some cases where the original claim contains equality only, the alternate hypothesis may not be "not =". Either "greater than" or "less than" would be the choice since only a given direction would make sense.

~Here is an example:

Original claim:  A given Rx is 90% effective in a treatment for a given sickness. Since the alternate hypothesis is an opposing view, it would not make much sense to use "not equal" for the alternate hypothesis. Being "greater than"  90% effective is not an opposing view, so we take the alternate hypothesis to be "less than" 90% effective. So, implied in the original claim is "at least 90%" effective. That way, it follows my above rules.

~Stating the conclusion~

~ When stating the conclusion, make sure you address the original claim.

~The best way to state the conclusion~

 a) Rejecting the null hypothesis:

    "There is sufficient evidence to conclude.....(use alternate hypothesis)"
     OR "There is insufficient evidence to conclude....(use null hypothesis)"
     Again, choose the one that addresses the original claim.

b) Not rejecting the null hypothesis:
     "There is sufficient evidence to conclude....(use null hypothesis)"
    OR"There is insufficient evidence to conclude...(use alternate hypothesis")

     Again, choose the one that addresses the original claim.