2801 Unit 9: statistics

Question 1

biostatistics

Answer 1

science of analyzing data and interpreting results
- used to solve problems in bio or health related fields

Question 2

univariate analysis

Answer 2

describes ONE variable in a data set using simple statistics like
frequencies, proportions, and averages

Question 3

bivariable analysis

Answer 3

examines the associations between TWO variables

Question 4

multivariable analysis

Answer 4

examine the relationships among 3 or more variables

Question 5

variable

Answer 5

a characteristic that can be assigned to more than one value
OR
Any quantity that varies from one entity to another

Question 6

2 qualitative variables

Answer 6

nominal and ordinal

Question 7

2 quantitative variables

Answer 7

discrete and continuous

Question 8

nominal variable

Answer 8

no obvious numerical way to rank
ex. favourite sport activity, you cant rank blood types

Question 9

ordinal variable

Answer 9

A variable with responses that span from first to last, from best to worst, from most favorable to least favorable, from always to never, or that are expressed using other types of ranked scales
ex. mild pain to severe pain (scale)

Question 10

continuous variable

Answer 10

can take any value
plotted as a line
ex. Blood pressure, temperature

Question 11

discrete variable

Answer 11

can take a finite limited number of values
plotted as dots
ex. age, #of drinks, you can own 2 dogs not 2.5

Question 12

interval variable

Answer 12

value 0 doesn’t mean absence of characteristic
ex. 0 degrees Celsius does not mean no temperature, and 100 degrees is not double 50 degrees. ex2: pH = 0

Question 13

ratio variable

Answer 13

can be plotted on a scale on which a value of 0 indicates the total absence of the characteristic
ex. heart rate, age, blood pressure

Question 14

mean calculation

Answer 14

add values and divide by how many you have

Question 15

median calculation

Answer 15

the middle value of all the numbers (if there is 2 middles then take the avg of those)

Question 16

Mode calculation

Answer 16

response listed the most
ex. 2 7 8 9 2 3 1 6
2 is represented twice therefore 2 is the the mode

Question 17

range calculation

Answer 17

range is the difference between the minimum and maximum values in the data set

Question 18

quartiles

Answer 18

rank values from smallest to largest then draw 3 lines separating the numbers in 4 equal parts

Question 19

Interquartile Range (IQR)

Answer 19

the middle 50% of values for a numeric variable (from 25th QR to 75th QR)
25th = the 2 values on either side added then /2
50th = same thing
75th same thing

Question 20

outlier

Answer 20

value that is distinct from the other observations and outside the expected range of values

Question 21

variance

Answer 21

[(each value in the set - the mean) squared] + [(next value in set - mean) ^2] + [(next value - mean)^2] do this until all values in set are done. then divide that number by how many values you have

Question 22

standard deviation

Answer 22

square root of variance

Question 23

standard error

Answer 23

standard deviation / root of sample size (# of values given)

Question 24

confidence interval

Answer 24

the expected value of a measure in a source population based on the value of that measure in a study population
- expect a 5% discrepancy (where CI misses capturing the true value of a measurement)

Question 25

fabrication

Answer 25

CREATE fake data

Question 26

falsification

Answer 26

misrepresentation of results

Question 27

comparative statistics

Answer 27

Tests that compare the characteristics of two or more independent populations
OR
test compares the before and after of 1 population being followed forward in time

Question 28

null hypothesis

Answer 28

no significant difference

Question 29

inferential statistics

Answer 29

use statistics from a random sample of a population to make assumptions about the population as a whole

Question 30

steps in hypothesis testing

Answer 30

1. take random sample
2. set 2 competing hypotheses (null and alt)
3. use sample statistics to decide western to accept or reject the null
4. determine, if null is really true, what the observed statistics will be

Question 31

p-value

Answer 31

measure how strongly the sample data agrees with the null

Question 32

parametric test

Answer 32

assumes the variables being examined have particular distributions ???

Question 33

nonparametric test

Answer 33

does not make assumptions about the distributions of responses
- used for ranked variables and when distribution of a ratio/internal variable is not normal ???