The Statistical Inference and Hypothesis Testing

Question 1

What is Statistical Inference?

Answer 1

Process of analyzing data from a sample to infer the true values or true effects in the population

Question 2

What are the two complementary approaches of statistical inference?

Answer 2

Hypothesis testing and Statistical estimation (confidence intervals)

Question 3

What are the characteristics of Hypotheses?

Answer 3

1. A declarative sentence
2. Describes a relationship between two or more variables
3. Testable by empirical means
4. Provides an indirect method of statistical inference

Question 4

What is the Null Hypothesis H0?

Answer 4

What the researches are attempting to nullify, main purpose is to disprove a proposed assumption

Question 5

What is the Alternate Hypothesis HA?

Answer 5

What happens if the null hypothesis is not true, hypothesis that researches are attempting to prove

Question 6

What are components of the hypothesis testing?

Answer 6

Method focus on testing the null hypothesis only and conclusions are made in terms of rejecting or failing to reject the null hypothesis?

Question 7

Distribution under H0 has what?

Answer 7

Sample Mean under the null hypothesis, centered on population mean U0

Question 8

Standard Deviation of the Population Mean is what?

Answer 8

Standard Error

Question 9

What is the formula for Standard Error of the Mean SEm?

Answer 9

SEm = SD / (square root of n)

Question 10

Distribution under HA has what?

Answer 10

Sample Mean under the alternative hypothesis, centered on population mean UA, assuming the expected effect or difference

Question 11

What does SEm represent?

Answer 11

How close the means of repeated samples will come to the population mean, describes the dispersion of means

Question 12

What is a Type 1 Error?

Answer 12

Reject the null when the null is true, false positive

Question 13

What is a Type II Error?

Answer 13

Fail to reject the null when the null is false, false negative

Question 14

How to find the probability of Type 1 error?

Answer 14

Confidence

Question 15

How to calculate Confidence?

Answer 15

1-a

Question 16

How to find probability of Type 2 Error?

Answer 16

Power

Question 17

How to calculate Power?

Answer 17

1-B

Question 18

Define Power

Answer 18

Power 1-B is the probability of conclusion there is a difference when one actually exists (HA is true), you want statistical power in a study

Question 19

What does the Z-Score show?

Answer 19

How many standard deviations away from the population mean we are

Question 20

What is Probability (p)?

Answer 20

The probability of observing the sample data if the null hypothesis is true

Question 21

What Apriori Alpha (a) level?

Answer 21

Specified in advance the critical value usually 0.05

Question 22

Compare p to a allows you to reject or accept the H0

Answer 22

p less than a = reject
p greater than a = accept

Question 23

What are the types of hypothesis testing?

Answer 23

Non-Directional and Directional

Question 24

Non Directional Tests are?

Answer 24

Two-tailed, look in both pos and neg directions
alpha a is cut into two areas, one at each tail to look a pos/neg critical values

Question 25

Directional Tests are?

Answer 25

One-tailed, look in only one direction Test of superiority and non-inferiority

Question 26

What is the formula to test the difference?

Answer 26

H0 = u1 - u2 = 0 the test is non-directional since the direction of the difference is not specified

Question 27

Research questions are framed as directional but..

Answer 27

tested using a non-directional test

Question 28

Rejecting the null says that there is a what?

Answer 28

Difference

Question 29

Failing to reject the null says that is what?

Answer 29

Insufficient evidence to conclude there is a difference

Question 30

What is testing for Equivalence?

Answer 30

Tests whether two quantities are within an acceptable range of each other

Question 31

Equivalence H0 = mean 1 - mean 2 =

Answer 31

greater than or equal to 10%

Question 32

Equivalence HA = mean 1 - mean 2 =

Answer 32

less than 10%

Question 33

What does rejecting the null say in testing for equivalence?

Answer 33

The that two are equivalent aka HA is less than 10%

Question 34

What is testing for Superiority?

Answer 34

Tests whether one quantity is greater than or less than the other

Question 35

Superiority H0 =

Answer 35

u1 - u2 < 0

Question 36

Superiority HA =

Answer 36

u1 - u2 > 0

Question 37

What does rejecting the null say in testing for superiority?

Answer 37

That one group is greater than than the other

Question 38

What is testing for Non-Inferiority?

Answer 38

Tests whether one quantity is no worse than a second quantity

Question 39

Non-Inferiority H0 =

Answer 39

Mean 1 - Mean 2 > Confidence Interval

Question 40

Non-Inferiority HA =

Answer 40

Mean 1 - Mean 2 < Confidence Interval

Question 41

What does rejecting the null say in testing for non-inferiority?

Answer 41

Says that one group is non-inferior to the other on the variable of interest

Question 42

How is non-inferiority different from equivalence?

Answer 42

Similar to equivalence but WITHOUT the absolute value because the test is directional

Question 43

What are the steps in Traditional Approach to performing hypothesis tests?

Answer 43

1. Convert the research question into appropriate null and alternate hypothesis 2. Select the appropriate statistical test 3. Select the desired significance level and the appropriate critical value for the statistical test 4. Calculate the test statistic 5. Compare the test statistic to the critical value and draw conclusions

Question 44

How do you calculate Degrees of Freedom?

Answer 44

Sample Size - Number of Groups

Question 45

How do you calculate the Significance Level?

Answer 45

a / (number of groups)

Question 46

How do you calculate the Critical Value?

Answer 46

Use degrees of freedom and the significance level, Planas said she would provide it

Question 47

How to calculate the test statistic?

Answer 47

Planas said it would be provided ONLY on Exam 1

Question 48

If the test statistic is greater than the critical value what does that mean?

Answer 48

You reject the null hypothesis meaning HA is true

Question 49

The probability number found is the change of finding a result of this magnitude

Answer 49

Planas said it would be provided ONLY on Exam 1

Question 50

You want the p value to be less than alpha

Answer 50

Because you want the p value to be less than the alpha 0.05 to reject the null hypothesis

Question 51

What does Statistically Significant mean?

Answer 51

Null hypothesis is reject after statistical analysis

Question 52

What does Clinical Significance mean?

Answer 52

Whether the findings are clinically or practically meaningful

Question 53

Does statistical significance prompt use of new medication?

Answer 53

No cause it does not mean it is clinically significant