211 Unit #4 Hypothesis

Question 1

Suppose that alpha is set to 0.05. A research team used inferential statistics to evaluate infection rates associated with 3 different types of dressings. The p value was 0.024. Can they reject the null hypothesis?

Select one:

a. No, because the p value is greater than alpha.
b. Yes, because the p value is less than alpha
c. No, because the p value is less than alpha.
d. Yes, because the p value is greater than alpha

Answer 1

b. Yes, because the p value is less than alpha

Question 2

Suppose you used inferential statistics to examine whether the number of glasses of water per day predicted surgical patients’ serum creatinine (mmol/L) and obtained a beta coefficient of b=-0.15, p=0.462. What is the best conclusion you could draw from this result?

Select one:

a. Each additional glass of water increases serum creatinine by 46.2%
b. Each additional glass of water increases serum creatinine by 0.15 mmol/L
c. Number of glasses of water explains 15% of the variance in serum creatinine
d. Number of glasses of water does not significantly predict serum creatinine

Answer 2

d. Number of glasses of water does not significantly predict serum creatinine

Question 3

Suppose a researcher has developed an educational intervention for new mothers about breastfeeding and she is interested in knowing whether the intervention has increased the mothers’ knowledge level. She sets alpha at 0.05, compares knowledge scores for 20 mothers before and after the intervention and obtains a p of 0.07 for the test statistic. Can she conclude that the mothers’ knowledge score were significantly better after the intervention?

Select one:

a. No, because the sample is too small.
b. No, because the p value is greater than 0.05.
c. Yes, because the difference between alpha and the p value is less than 1.
d. Yes, because the p value is greater than 0.05.

Answer 3

b. No, because the p value is greater than 0.05.

Question 4

Which of the following alpha levels can be interpreted as a highly statistically significant result?

Select one:

a. p=0.0002
b. p=0.20
c. p=0.02
d. p=0.002

Answer 4

a. p=0.0002 This is the most highly statistically significant result.

Question 5

Which of the following levels of significance would help decrease the chance of having a Type 11 error?

Select one:

a. 0.001
b. 0.01
c. 0.05
d. 0.005

Answer 5

c. 0.05

Question 6

Which of the following is an example of random error in measurement?

Select one:

a. Use of a mismarked tape measure to determine infant head circumference.
b. Inadvertent deletion of one question form the questionnaire sent to all subjects in a study.
c. Consistent use of a tuning fork pitched too high.
d. Occasional discussion of questions with some subjects during completion of the measurement tool

Answer 6

d. Occasional discussion of questions with some subjects during completion of the measurement tool

Question 7

The likelihood that a statistical value obtained through analysis of the data is likely to occur in any two samples selected from the same population is called:

Select one:

a. probability.
b. degrees of freedom.
c. induction.
d. interval estimation.

Answer 7

a. probability.

Question 8

A researcher notes that although no mathematical significance was found, some premature infants who were exposed to soothing music for 6 hours a day exhibited lower heart rates and less crying. This finding would have which type of significance?

Select one:

a. Inferential
b. Statistical
c. Clinical
d. Genera

Answer 8

c. Clinical

Question 9

Which of the following is true about Type I errors?

Select one:

a. Considered only when results are not statistically significant in a study.
b. More likely to happen when p is less than .01 rather than p is less than .05.
c. Occur when the researcher says there is significance, but findings are actually not statistically significant.
d. Extremely likely to happen when p is less than .001.

Answer 9

c. Occur when the researcher says there is significance, but findings are actually not statistically significant.

Question 10

On the basis of statistical findings, Ron determines that the differences between males and females on a test of spatial reasoning are not due merely to chance. If, in fact, there are no gender differences in the population, Ron will have made a:

Select one:

a. Type II error.
b. Type I error.

Answer 10

b. Type 1 error

Question 11

what is the first step for ideas that can be examined using statistics

Answer 11

prepare a research question about the relationships that will be explored

Question 12

what is the second step for ideas that can be examined using statistics

Answer 12

the researcher specifies a hypothesis

Question 13

What is a hypothesis

Answer 13

a statement that predicts the outcomes of a study

Question 14

describe a casual hypothesis

Answer 14

states that X (IV) causes a change in Y (DV) requires tight control over the study

Question 15

Describe an associative hypothesis

Answer 15

suggests that an association exists between X and Y

Question 16

How many variables are in a simple hypothesis

Answer 16

1 IV; 1 DV

Question 17

How many variables are in a complex hypothesis

Answer 17

2 or more IV’s; 2 or more DV’s

Question 18

Describe directional hypotheses

Answer 18

states that a relationship exists and identifies the direction of that relationship

Question 19

describe non-directional hypotheses

Answer 19

indicates that a relationship exists but does not identify a direction

Question 20

describe research (alternative) hypotheses

Answer 20

statement of the actual expected relationships between variables

Question 21

describe statistical (null) hypotheses

Answer 21

states that no relationship exists between IV and DV

Question 22

what does alpha mean

Answer 22

defined as the chance of making a type 1 error; also called the ‘level of significance’ set at 0.05.

Question 23

what does beta mean

Answer 23

defined as the chance of making a type 2 error set at 0.2

Question 24

what is a type 1 error

Answer 24

rejecting the null hypothesis when it is true

Question 25

what is a type 2 error

Answer 25

failing to reject the null hypothesis when it is false

Question 26

If the consequences of a Type 1 error are expensive or serious, _____ alpha to _____ the probability of a type 1 error

Answer 26

decrease; reduce

Question 27

If the consequences of a type 1 error are not expensive or serious but type 2 consequences are, _____ alpha in order to _____ beta

Answer 27

increase; decrease

Question 28

The main way to decrease both types of errors is?

Answer 28

increase the sample size

Question 29

in order to be statistically significant p must be _____

Answer 29

= .05

Question 30

power = ______

Answer 30

1 - beta(.2)

Question 31

What is clinical significance

Answer 31

refers to a difference that is large enough to indicate a preferred course of action in clinical practice

Question 32

A statistically significant hypothesis = _______

Answer 32

finding is unlikely to have occurred by chance.