Statistical Inference

Question 1

What is the process of Quantitative Research?

Answer 1

1. Define the research hypothesis
2. Collect data and explain how you measure (or operationally define) what you are studying and set out the variables to be studied.
   3.Conduct hypothesis testing and draw conclusion

Question 2

What is a statistical hypothesis

Answer 2

An assertion, claim or prediction concerning one or more population parameters.

Question 3

What is hypothesi testing used to do?

Answer 3

Established whether a research hypothesis extends beyond those individualds examined in a single study.

Question 4

What are the 5 steps of hypothesis testing?

Answer 4

1. State null hypothesis (H0) then select alternative hypothesis (HA)
2. Determine the level of significance
3. Make a one- or two-tailed prediciton
4. Compute value of the test statistic from the sample
5. Decision: Reject H0 if the test ststaitic has a value in the critical region otherwise accept H0

Question 5

What is the Null Hypothesis

Answer 5

-H0 is essentially the “devils advocate” position
-It assumes that whatever you are trying to prove did not happen

Question 6

What is Level of Significance?

Answer 6

The probability of making a Type 1 error

Question 7

What does a p-value of 0.03 mean?

Answer 7

There is a 3% probability of making a Type 1 error - rekecting H0 when the null hypothesis is true

Question 8

What does a significance level of 0.05 mean?

Answer 8

-No more than a 5% probability of error is allowed.
-5% is widely used in academic research

Question 9

On-tailed predicitons

Answer 9

-If HA has a positive direction, the hypothesis is one-tailed.
-If HA has a negative direction, the hypothesis is also one-tailed

Question 10

Two-tailed predictions

Answer 10

-A two-tailed prediction means that we do not make a choice over the direction
-It simplly implies that the effect could be positive or negative

Question 11

What is Sampling Distribution of the Sample Means (SDM)

Answer 11

-SDM is a probability distribution. It consists of the means of all random samples of size n that can be drawn from a population
-When n is sufficiently large the sampling distribution of x will be approximately normal. This is called “Central Limit Theorem”

Question 12

Central Limit Theorem (When n>30)

Answer 12

-The mean of all possible sample means equals the population mean.
-The standard deviation of all the possible sample means is known as the standard error