Basic Statistical Concepts

Question 1

Stages in transforming data into information and evidence

Answer 1

1) Data
2) Information
3) Evidence
4) Knowledge
5) Decisions
5) Impact

Question 2

To change data into information you must

Answer 2

compile, manage and analyze

Question 3

to turn information into evidence you must

Answer 3

integrate, interpret and evaluate the information

Question 4

making evidence into knowledge

Answer 4

format for presentation to planners and stakeholders

Question 5

Knowledge to Decisions

Answer 5

Influence plans and decisions (planners and policy makers)

Question 6

Making decisions have impact

Answer 6

implement decisions

Question 7

Turn impact to data

Answer 7

monitor indicators for change

Question 8

Arithmetic average of a distribution

Answer 8

Mean

Question 9

Equation for mean

Answer 9

Mean = (Total score/ sample size)

Question 10

Only measure that can be manipulated alebraically

Answer 10

Mean

Question 11

Most sensitive to skew and outliers

Answer 11

Mean

Question 12

the value in the distribution that occurs most frequently

Answer 12

mode

Question 13

Always located at the peak of the distribution when in graphs

Answer 13

Mode

Question 14

Insensitive to extreme values or outliers

Answer 14

Mode

Question 15

Middle value in an ordered array of data

Answer 15

Median

Question 16

Divides the upper half of the distribution from the lower half

Answer 16

Median

Question 17

Hardly affected by outliers

Answer 17

Median

Question 18

Measurement of symmetry and the extent to which a distribution curve leans

Answer 18

Skewness

Question 19

Arrangement of mean median and mode when a graph is positively skewed

Answer 19

Mode < Median < Mean

Question 20

In a graph, when the tail extends to the right

Answer 20

Positively skewed

Question 21

Skewness when higher values have lower frequencies

Answer 21

Positively skewed

Question 22

In graphs, skewed to the left

Answer 22

Negatively skewed

Question 23

In graphs, tail extends to the left

Answer 23

Negatively skewed

Question 24

Arrangement of mean, median and mode when graph is positively skewed

Answer 24

Mode > Median > Mean

Question 25

Higher values have higher frequencies

Answer 25

negatively skewed

Question 26

no skew, balanced tails

Answer 26

Bell curve

Question 27

Two parameters that determine the normal curve distribution

Answer 27

mean | standard deviation

Question 28

Measure of variability for the distance away from the mean

Answer 28

Standard deviation

Question 29

Formula for SD from the mean

Answer 29

SD from the mean [(X-Mean)/SD)

Question 30

Percentage of area from -1SD to +1SD

Answer 30

68%

Question 31

Percentage of area outside of -1SD to +1SD

Answer 31

32%

Question 32

Percentage of the area between -2SD and +2SD

Answer 32

95%

Question 33

What percentage of the observations would be more than +-2SD away from the mean?

Answer 33

5%

Question 34

What percentage of observations would lie within 3SD of the mean?

Answer 34

99.7%

Question 35

1 SD above and below the mean

Answer 35

68%

Question 36

2 SD above and below the mean

Answer 36

95%

Question 37

3 SD above and below the mean

Answer 37

99.7

Question 38

The SD of a sampling distribution that determines whether a sample mean will be higher or lower than the population mean

Answer 38

Standard error

Question 39

Equation for SE

Answer 39

``` SE = (s/ sqrt n) s= sample SD n= sample size ```

Question 40

Range within which the true magnitude of effects lies with a certain degree of assurance or confidence

Answer 40

Confidence interval

Question 41

Disprove prevailing hypothesis, always set up as hypothesis of no effect (null)

Answer 41

Refutationalism/ Falsification

Question 42

Determine sample size from confidence interval

Answer 42

large sample size --> more stable estimate --> narrow CI

Question 43

Three threats to validity

Answer 43

Sampling variability Confounding variables Bias

Question 44

Methods of evaluating sample variability

Answer 44

Hypothesis testing | Interval estimation

Question 45

Samples drawn at random from a population may give varying measurements of statistical data

Answer 45

Sampling variability

Question 46

Used to test for validity and address sampling variability

Answer 46

hypothesis testing

Question 47

Steps of hypothesis testing

Answer 47

1) Set up two hypothesis 2) Prove null hypothesis wrong 3)

Question 48

Hypothesis wherein there is no relationship between exposure and outcome

Answer 48

Null hypothesis

Question 49

Hypothesis wherein there is a relationship between exposure and outcome

Answer 49

Alternative hypothesis

Question 50

Alternative hypothesis wherein direction is determined

Answer 50

One tailed

Question 51

Alternative hypothesis wherein direction is not determined

Answer 51

Two tailed

Question 52

Used to determine whether the hypotheses may be accepted or regected

Answer 52

Test statistic

Question 53

A statistical test assumed to have normal distribution, used to determine whether two population means are different given a large sample size

Answer 53

Ztest

Question 54

Equation for Ztest

Answer 54

z=

Question 55

Numerator of Z

Answer 55

magnitude of the difference between groups

Question 56

Denominator of Z

Answer 56

the variability of the estimate

Question 57

You want a large test statistic

Answer 57

big difference between groups, large sample size or | smaller variability of the estimate

Question 58

The probability of obtaining the observed result due to chance

Answer 58

P value

Question 59

You want a low p value

Answer 59

Larger test statistic

Question 60

Study results may say treatments differ but the truth is that hey do not

Answer 60

Type 1 error false positive

Question 61

Study results say treatments do not differ but the truth is they do

Answer 61

Type 2 false negative