Intro to Biostats

Question 1

population

Answer 1

study subjects of all individuals

Question 2

what is the study population

Answer 2

final group of individuals selected for a study

Question 3

sample

Answer 3

subset or portion of the full population

“representatives”

Question 4

when is it useful to choose a sample

Answer 4

when studying complete population is not feasible

random process commonly utilized to draw sample

Question 5

what are the measurements in a study?

Answer 5

dependent and independent variables

Question 6

which are outcome variables, dependent or independent?

Answer 6

dependent

Question 7

how are comparisons made between study groups?

Answer 7

statistical analyses

Question 8

how are inferences made about the sample?

Answer 8

deprived from measurements and their comparisons

also utilized for entire populations by making inferences for generalizability

Question 9

null hypothesis

Answer 9

research perspective which states there is no true difference between groups being compared

most conservative and commonly utilized

Question 10

researchers accept or reject this perspective based on results

Answer 10

null hypothesis

Question 11

what statistical perspectives are taken by researchers with null hypothesis

Answer 11

superiority
non inferiority
equivalency

Question 12

alternative hypothesis

Answer 12

research perspective that states there will be a true difference between groups being compared

Question 13

2 key attributes of data measurement

Answer 13

magnitude (dimensionality)
consistency of scale (fixed interval)

also include rational zero

Question 14

a scale is consistent if

Answer 14

there are equal and measurable spacing between the units

Question 15

3 key levels and attributes of measures

Answer 15

nominal
ordinal
interval

Question 16

nominal attributes

Answer 16

NO magnitude
NO consistency of scale
NO rational zero

labeled variables without qualitative characteristics (i.e. career, gender)

Question 17

ordinal attributes

Answer 17

YES magnitude
NO consistency of scale
NO rational zero

(i.e. pain scales, “strongly agree, strongly disagree, agree, neutral)

Question 18

interval/ratio attribute

Answer 18

YES magnitude
YES consistency of scale
no or yes rational zero

(i.e. number of living siblings, personal age, physiological measurement)

Question 19

changing levels of data: can you go up or down in specificity?

Answer 19

you can only go DOWN in specificity, never up

Question 20

how can you convert blood pressure down the scale?

Answer 20

interval: actual numbers (i.e. 120/80)
ordinal: hypertensive, hypotensive, normal
nominal; high blood pressure, low blood pressure

Question 21

which attributes are descrete? interval?

Answer 21

nominal and ordinal descrete (only these choices)

interval: continous

Question 22

descriptive statistics

Answer 22

non comparative, simple description of various elements of study’s data

Question 23

measures of central tendency/dispersion

Answer 23

mode/median/mean
outliers
minimum/maximum/range
IQR

Question 24

variance

Answer 24

from the mean

difference in each individual measurement value and the group’s mean

Question 25

standard deviation

Answer 25

square root of the variance value (restores units of mean)