Statistics and Research

Question 1

What are the steps to implement a research study?

Answer 1

1. identify problem
2. develop research question
3. develop hypothesis (null and alternative)
4. methodology
5. collect and analyze data
6. conclusion (decisions based on data collected)

Question 2

What are the steps to write a research report?

Answer 2

1. abstract
2. introduction
3. literature review
4. methodology
5. results
6. discussion
7. conclusion
8. implication

Question 3

What is the difference between independent and dependent variables?

Answer 3

with independent variable, you can manipulate or control (treatment variable)
ex: how well you prepare for the exam

dependent: depends on independent (response/outcome variable)
ex: RD test score –> depends on how much you study, how well you slept, test anxiety

Question 4

p value

Answer 4

• helps you determine the significance of your study

- p 0.05 is probability that null hypothesis is true (fail to reject the null hypothesis)

Question 5

Standard deviation and the percentages away from z-score (mean)

Answer 5

1 SD = 68%
2 SD = 95%
3 SD = 99.7%

Question 6

What is the mean?

Answer 6

average of all scores

(2+4+4+7+8) / 5 = 5

Question 7

What is the median?

Answer 7

The one in the middle

(2,4,4,7,8) = 4

Question 8

What is the mode?

Answer 8

the one featured most

(2,4,4,7,8) = 4

Question 9

What are the values for the correlation coefficient (r value)?

Answer 9

0.0-0.4 = low (weak) correlation
0.4-0.7 = moderate correlation
0.7-1 = strong correlation
the closer r is to +1 or -1, the more closely the 2 variables are related

Question 10

Quasi-experimental (observational research)

Answer 10

before and after, no control group

analytical/applied research

Question 11

correlational studies (exploratory/ecological)

Answer 11

degree to which a relationship exists between 2 or more variables
uses correlation coefficient (r-value)
descriptive (basic) research

Question 12

case study/case report/case series

Answer 12

observation of 1 or more people or events

descriptive (basic) research

Question 13

qualitative studies

Answer 13

uses open-ended questions
interviews, observations, focus groups, surveys, questionnaires
descriptive (basic research)

Question 14

cohort study (incidence)

Answer 14

longitudinal study
can be prospective or retrospective
analytical research

Question 15

randomized clinical trial (experimental design)

Answer 15

assigned at random
uses experimental and control group
analytical research

Question 16

cross-sectional (prevalence)

Answer 16

how many currently have disease

Question 17

meta-analysis

Answer 17

quantitative
review of literature; review of numerous small studies
analytical research

Question 18

cross-over design

Answer 18

crossed over to the other treatment

analytical research

Question 19

case control

Answer 19

CCC = case control compares with and without disease

analytical research

Question 20

What is reliability?

Answer 20

degree of consistency with which a test measures what it’s supposed to measure

Question 21

What is validity?

Answer 21

truthfulness and effectiveness of a study

Question 22

What is sensitivity?

Answer 22

true positive = sick people are sensitive = probability that a + test among a patient with disease

Question 23

What is specificity?

Answer 23

true negative = probability of a negative test among patients without a disease = healthy people test negative

Question 24

What is type I error?

Answer 24

false positive= you said your findings were significant (there was a difference among 2 groups) but they weren’t (there was no difference = supports null hypothesis)

ex: you reject a null hypothesis (you are saying there is a difference between groups) when in reality it’s true that there are no observed differences between groups
- a test result which incorrectly showed positive

Question 25

What is type II error?

Answer 25

false negative = you concluded that your research was not significant when in fact it was (you said that the null hypothesis was true (no difference) but in reality the alternative hypothesis was true (there was a difference)

ex: failing to reject null hypothesis (meaning the test has not shown any difference between groups) when it’s not true (there is a difference between groups)
- result came out negative but it’s false that it’s negative
- pregnant woman was told by MD she’s not pregnant
- type II error is worse

Question 26

What is Hawthorne Effect?

Answer 26

Placebo effect/ Elton Mayo

Question 27

What is analysis of variance? (ANOVA)

Answer 27

a statistical test used to study group differences; tool used for validity (how accurately it measures what it’s intended to measure)
used in meta analysis

Question 28

What is t-test?

Answer 28

a statistical test involving interval or ratio data that assesses whether the means of 2 groups are statistically different from each other

Question 29

descriptive statistics

Answer 29

used to organize, summarize, and describe a group

Question 30

inferential statistics

Answer 30

relationships and causalities you find in a sample and used to make generalizations (inferences) about a population

Question 31

chi-test

Answer 31

measures the association between 2 nominal and/or ordinal variables