Hypothesis Testing

Question 1

Null Hypothesis

Answer 1

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

Question 2

Statistical Significance Test

Answer 2

A statistical significance test measures the strength of evidence that the data sample supplies for or against some proposition of interest.

Question 3

P-value

Answer 3

the probability of obtaining the observed data set if the null hypothesis were true. The lower the p-value, the more significant it is said to be. If the p-value is very low, we say the result is highly significant.

NOTE: If the p-value is small, then we say that the data is unlikely to have occurred if the null hypothesis were true. We have NOT disproved the null hypothesis; the sample is unlikely BUT NOT IMPOSSIBLE.

Question 4

One-sample T-test

Answer 4

This test is appropriate when a continuous variable is recorded on a single sample of individuals or items and the mean value is to be tested against some hypothesized population mean.

Question 5

Alternative Hypothesis

Answer 5

The hypothesis that there is a significant difference between specific populations (sample means are not equal)

Question 6

Critical Value

Answer 6

A critical value is a point (or points) on the scale of the test statistic beyond which we reject the null hypothesis, and, is derived from the level of significance α of the test. Critical value can tell us what is the probability of two sample means belonging to the same distribution. A higher critical value means lower the probability of two samples belonging to same distribution.

Question 7

Important factors before performing test

Answer 7

1) sample is random

2) determine distribution