In: Statistics and Probability
Which of the following is an example of a two-tailed research hypothesis?
Select one:
a. The number of reported migraine headaches will decrease when migraine patients take the new medication.
b. Participants will have remember more words when they study using visual imagery compared to memorization.
c. The use of colored filters will change a subject's perception of depth.
d. Both a and b are correct.
Solution:
In hypothesis testing we state two hypothesis: Null hypothesis H0 and alternative hypothesis H1.
Null hypothesis is a hypothesis of no difference
for example:
whereas alternative hypothesis is opposite or alternative to H0.
It is less than ( < ) type or greater than ( > ) type or Not equal to ( ) type.
If H1 is < or > type , then it is One tailed test whereas if H1 is , then this is two-tailed test.
We have to find an example of a two-tailed research hypothesis from given statements.
Lets consider: a) The number of reported migraine headaches will decrease when migraine patients take the new medication.
This means that we have to test : The number of reported migraine headaches will decrease , so this is less then ( < ) test, thus this is one tailed test.
Now consider b) Participants will have remember more words when they study using visual imagery compared to memorization.
So this indicates Greater than ( > ) type test. So this is also a one tailed test.
Now consider c) The use of colored filters will change a subject's perception of depth.
Here it says The use of colored filters will change, so this change is non-directional and can be Less than or greater than some specified value.
Thus this is a two tailed test.
Thus correct option for an example of a two-tailed research hypothesis from given statements is:
c) The use of colored filters will change a subject's perception of depth.