Statistics

Question 1

What are inferential statistics?

Answer 1

In inferential statistics we test the probability that the test hypothesis is true. The stats that we run give us the probability that the results from the data analysis is due to chance alone (i.e., due to a fluke).

Question 2

What is quantitative research?

Answer 2

Quantifying relationships between variables

Measure variables with a sample of participants
Express the relationship between the variables

Question 3

What are variables?

Answer 3

A concept or construct

can have more than one value (i.e., it can vary).

The value can be different for each research participant

Question 4

What is a constant?

Answer 4

A concept or construct

always has the same value for each participant

Question 5

What is an independent variable?

Answer 5

Explains or causes a change in another variable

Not dependent on another variable

Manipulated by the researcher

Question 6

What is a dependent variable?

Answer 6

Explained or caused by IV.

Level is dependent on the other variable

Of interest in explaining and understanding

Question 7

What is conceptualization in regards to measurement?

Answer 7

Accepting a nominal definition

Question 8

What is operationalization in regards to measurement?

Answer 8

Accepting a way of measuring

Question 9

What is precision?

Answer 9

How repeatable are measurements

Question 10

What is accuracy?

Answer 10

How close is the measurement to the true value of what is being measured?

Question 11

Two main stems of levels of measurement?

Answer 11

Categorical and numerical

Question 12

Two main stems of categorical measurement?

Answer 12

Nominal and ordinal

Question 13

Two main stems of numerical measurement?

Answer 13

interval and ratio

Question 14

What does nominal data do?

Answer 14

Classifies

Question 15

What does ordinal data do?

Answer 15

Classifies

Orders

Question 16

What does interval data do?

Answer 16

Classifies
Orders
Equal intervals

Question 17

What does ratio data do?

Answer 17

Classifies
Orders
Equal intervals
Has ab absolute zero

Question 18

How are variables assessed in nominal data?

Answer 18

Variables are
Discrete – data falls into categories
Non-metric – no order in categories

Question 19

How are variables assessed in ordinal data?

Answer 19

Variables are
Discrete – data falls into categories
Order in the categories; ranking

Tells whether participants are different
(one can be more or less than other group)

Question 20

How are variables assessed in interval data?

Answer 20

Variables are legitimate numbers and have equal intervals between them.

No zero point

Question 21

How are variables assessed in ratio data?

Answer 21

Have a true zero, equal intervals and is very precise

Question 22

Main concerns for measurement?

Answer 22

Constraints (time, funds, equipment)

Validity (are we measuring the construct?)

Reliability (are the results repeatable?)

Question 23

How do we know we a measuring a concept?

Answer 23

Face value
Content validity
Criterion validity
Construct validity

Question 24

What should content validity be?

Answer 24

It should cover the entire range of meanings included in the concept.

Based on judgement

Question 25

What is criterion validity?

Answer 25

Checking against an external criterion believed to be another indicator of the same construct

Question 26

Main stems of criterion validity?

Answer 26

Predictive validity Concurrent validity Known groups validity

Question 27

What is predictive validity?

Answer 27

Predict some future criterion that expected to predict? ➢Does attendance at BIOL1900 lectures accurately predict student performance on exams?

Question 28

What is concurrent validity?

Answer 28

Relate to some known criterion concurrently? ➢Do scores on a measure of health-related quality of life correspond to the ratings based on clinician interviews?

Question 29

What is known groups validity?

Answer 29

Differentiate people in the way you would expect? ➢Does grip strength differentiate between those of low and high risk of cardiovascular mortality?

Question 30

What is construct validity?

Answer 30

Relates to other constructs in a way that is expected based on theoretical relationships

Question 31

Two main stems of construct validity?

Answer 31

Convergent and divergent validity

Question 32

What is convergent validity?

Answer 32

Associated with other measures that it should be related to. ➢Do scores on a vertical jump test correspond to Wall Sit Test times (leg strength)? ➢Do results on BIOL1900 Practice Quizzes relate to Mid-Semester Exam results?

Question 33

What is divergent validity?

Answer 33

Does not associate with measures of other constructs as closely as it does with other measures of same construct ➢Do BSS scores relate more to measures of Sit & Reach than they do to Standing Long Jump?

Question 34

Most critical components of reliability?

Answer 34

Degree of consistency Degree of repeatability Degree of agreement

Question 35

Three ways to describe data?

Answer 35

Frequency, central tendency and variability

Question 36

Three measures of central tendency?

Answer 36

Mean, median and mode

Question 37

Three measures of variability?

Answer 37

Range, IQR and standard vardeviation

Question 38

What does univariate refer to?

Answer 38

Frequency: involving one variate or variable quantity.

Question 39

What does range tell us?

Answer 39

The amount of variation (dispersion) in a data set

Question 40

How is range calculated?

Answer 40

By subtracting the minimum score from the maximum score

Question 41

What graph is typically used for inter-quartile range?

Answer 41

Box and whisker plot

Question 42

How is the inter quartile range calculated?

Answer 42

By subtracting the 25th percentile score from the 75th

Question 43

Equation for probability?

Answer 43

Possible successful outcomes / # possible outcomes

Question 44

What is a type 1 error?

Answer 44

You find a significant relationship but one does not exist in the real world

Question 45

What is a type 2 error?

Answer 45

You find no significant relationship when one does exist in the real world

Question 46

Three factors of the correlation coefficient?

Answer 46

Sign (+/-) Magnitude (0 to 1) Significance (p<0.05)

Question 47

Why is it called p test?

Answer 47

Pearson's r Test for significance

Question 48

What are the two types of t-tests?

Answer 48

Independent-samples t-test and paired-samples t-test

Question 49

What is an independent samples t-test?

Answer 49

Comparison of two different groups (eg control vs intervention)

Question 50

What is a paired-samples t-test?

Answer 50

The comparison of repeated measures; one group on two occassions

Question 51

Assumptions of a t-test

Answer 51

Independent variable only from two groups Dependent variable normal distributed Data measured on interval scales The variance has homogeneity

Question 52

How is a t-test calculated?

Answer 52

It is the difference between means, divided by pooled standard deviation

Question 53

What is a chi-square test?

Answer 53

Test for a relationship between two nominal (categorical) variables Test for independence of the two variables (ie that one is not dependent on the other) Compares the obtained frequencies within each category to the frequencies expected in those categories by chance

Question 54

Assumptions of chi-squared test?

Answer 54

Each person/item/entity contributes to only one cell Expected cell frequencies should be >5

Question 55

Calculation for degrees of freedom? (in chi-squared test)

Answer 55

n-1

Question 56

How is a t-test calculated?

Answer 56

It is the difference between means, divided by pooled standard deviation