Question

Johaan Sri believes that his new drug Krnili-alpha can enhance memory performance in elementary school children. He has gained access to the local school system and appropriate permissions to conduct a study which would allow him to test the memory of these children with and without the drug. For each child he records the number of facts the student recalls with the drug and without the drug (repeated measures design). If he uses a sign test, explain the two one-tailed and one two-tailed tests he could use to analyze his data. Write out the three different hypotheses that are tested by each one of these tests. Which one of the three should he use? Explain why he should use it in terms of his research question. [NOTE: For this you will have to keep track of the improvement in memory to tell the two types of sign tests apart.]

Answer 1

One tailed Hypothesis.

case-1

Drug increases the memory power of the students.

H₀ : Drug does not increases the memory power of the students.

H₁ : Drug does increases the memory power of the students.

case-2

Drug does not increases the memory power of the students.

H₀ : Drug does increases the memory power of the students.

H₁ : Drug does not increases the memory power of the students.

Two tailed test

Drug affects the memory power of the students.

H₀ : Drug does not affect the memory power of the students.

H₁ : Drug does affect the memory power of the students.

We use case-1 One tailed Hypothesis. Because it clearly defines his research purpose.

Drug increases the memory power of the students.

H₀ : Drug does not increases the memory power of the students.

H₁ : Drug does increases the memory power of the students.