Lecture 5 Chapter 5 Selecting and Interpreting Inferential Statistics

Question 1

If the P value is less than or equal to the alpha value then you ______ the null hypothesis?

Answer 1

Reject

Question 2

If the P value is less than the alpha value then you ______ the null hypothesis?

Answer 2

Fail to reject the null or accept the null

Question 3

What does the p value indicate?

Answer 3

The percent of how much of your results are due to coincidence/randomness

Question 4

What do we use to decide whether to accept or reject the null hypothesis? Two things?

Answer 4

P-value
Alpha Level

Question 5

What is a type 1 error ?

Answer 5

rejecting a true null hypothesis (when p value is greater than Alpha)

Question 6

What is a type 2 error?

Answer 6

-Accepting a false when it is statistically significant
-Accepting null hypothesis when we shouldn’t

Question 7

Why are type 1 and 2 errors related?

Answer 7

As the probability of making a Type I error increases, the probability of making a Type II error decreases, and vice-versa

Question 8

What value determines the probability of making a Type I error?

Answer 8

Alpha

Question 9

If the alpha is set at 0.01, the researcher how likely to commit Type I errors?

Answer 9

1% of the time

Question 10

If the alpha is set at 0.05, the researcher how likely to commit Type I errors?

Answer 10

5% of the time

Question 11

If the alpha is set at 0.10, the researcher how likely to commit Type I errors

Answer 11

10% of the time

Question 12

Researchers don’t like making _____ errors, so they tend to have very low alpha values

Answer 12

Type 1 errors

Question 13

The alpha level describes the_________researchers place in their research results

Answer 13

level of confidence

Question 14

What are the three steps to seeing if you have a statistically significant results?
ASSOCIATION QUESTION

Answer 14

1) First, determine if you have a statistically significant association (by comparing the computed p-value to the selected alpha-level)
2) Second, determine the effect size of the association (see Table 5.5).
3) Third, determine the direction of the association using the sign in front of the correlation coefficients.

Question 15

What are the three steps to seeing if you have a statistically significant results?
DIFFERENCE QUESTION

Answer 15

1) First, determine if you have a statistically significant difference (by comparing the computed p-value to the selected alpha-level)
2) Second, determine the direction of the difference or the direction of effect (by identifying the group with the highest mean or mean rank or frequency)
3) Examine the clinical or practical significance of the difference

Question 16

What are the upper and lower limits when we reject the null hypothesis?

Answer 16

both positive
both negative

Question 17

What are the upper and lower limits when we fail to reject the null hypothesis?

Answer 17

One negative and one positive

Question 18

When Levene’s test is significant do we assume equal variance or do not assume equal variance?

Answer 18

When Levene’s test is significant we do not assume equality of variance

Question 19

When Levene’s test is NOT significant do we assume equal variance or do not assume equal variance?

Answer 19

A non-significant p value of levene’s test show that the variances are indeed equal and there is no difference in variances of both groups

Question 20

TRUE/FALSE
The larger the sample, the more likely the results will be statistically
significant

Answer 20

True

Question 21

Any association or difference can be statistically significant if sample sizes are ______

Answer 21

Large enough

Question 22

The bigger the _______ it is less likely our research results would be due to chance

Answer 22

sample

Question 23

What does statistical power give us? Three things

Answer 23

-Ability to reject the null hypothesis when we really should
* Ability to find a true difference or association that actually exists
* Ability to claim we have statistically significant results

Question 24

How do we increase power?
two options

Answer 24

Have a low alpha value
Have a large sample size

Question 25

Statistical Significance does mean real-life importance?
true/false

Answer 25

False

Question 26

Real-life importance of statistical results is referred to as______

Answer 26

Practical or
Clinical Significance

Question 27

If a result is practically important, it means that?

Answer 27

There is real life significants

Question 28

Determining whether a statistically significant research result has practical or clinical importance in real-life is?

Answer 28

Subjective

Question 29

Statistical significance ______ or imply clinical or practical significance!
does or does not

Answer 29

does not

Question 30

How to determine the practical or clinical significance of a statistical test result?

Answer 30

Because statistical significance doesn’t imply clinical or practical significance, some researchers use effect sizes to determine practical significance of their results

Question 31

How does effect size direction work for differences questions ?

Answer 31

Compare group means (for a scale DV) or the mean ranks (for an ordinal DV) or the frequencies (for a nominal DV)Which group did “better”?

Question 32

When you are calculating effect size direction for difference questions what do you compare in scale data?

Answer 32

Means

Question 33

When you are calculating effect size direction for difference questions what do you compare in ordinal data?

Answer 33

Mean Ranks

Question 34

When you are calculating effect size direction for difference questions what do you compare in nominal data?

Answer 34

Which group did better

Question 35

Effect size is defined?

Answer 35

as the strength of the relationship between the independent variable and the dependent variable,

Question 36

What is effect direction?

Answer 36

the directions of the results
EXAMPLE:
as eating candy goes up so does cavities

Question 37

What is cross-tabulation?

Answer 37

A two- (or more) dimensional table that records the number (frequency) of respondents that have the specific characteristics described in the cells of the table.