Chapter 1, 2, 3, 8

Question 1

what is a population

Answer 1

entire group of people or data you want to understand (ie. all diabetics in the country)

Question 2

what is a sample

Answer 2

a subgroup of the whole (all diabetics in a single town, but not the whole country)

Question 3

what is an element

Answer 3

a single observation (single patient with diabetes)

Question 4

what are descriptive studies

Answer 4

simply describe the data pertaining to a population or a sample

Question 5

what are inferential studies

Answer 5

tries to infer the features of a population from the limited data found in a sample

Question 6

what is a parameter

Answer 6

a number that describes a population characteristic (both start with P)

Question 7

what is a statistic

Answer 7

a number that describes a sample characteristic (both start with S)

Question 8

what is sampling error?

Answer 8

an acknowledgment that people and measurements normally vary, even if a sample is randomly chosen from the population in an unbiased way

Question 9

How do you reduce sampling error?

Answer 9

increase the size of the sample

Question 10

what is selection bias?

Answer 10

the researcher has not selected the sample randomly, but with a bias toward particular characteristics

Question 11

With selection bias, what will be wrong?

Answer 11

the conclusions about the general population

Question 12

Does increasing sample size correct selection bias?

Answer 12

No

Question 13

what is validity?

Answer 13

the accuracy of a test

Question 14

what is another word for invalid?

Answer 14

inaccurate

Question 15

what is reliability

Answer 15

how repeatable a test is

Question 16

what. is a variable

Answer 16

anything that changes

Question 17

what is an independent variable

Answer 17

one that influences variation

Question 18

what is a dependent variable

Answer 18

the result of applying the independent variable

Question 19

what axis is the independent variable normally plotted on?

Answer 19

x axis

Question 20

what axis is the dependent variable plotted on?

Answer 20

the y axis

Question 21

a normal Gaussian curve has what shape

Answer 21

a classic bell shape

Question 22

A curve that is not gaussian may be ____ or ____

Answer 22

skewed or kurtotic (excessively peaked or flat)

Question 23

what is the multiplication rule

Answer 23

the probability of a patient having disease A X the probability of a patient having disease B

(shows you the probability of a patient having both diseases)

-A and B situation

Question 24

what is the addition rule

Answer 24

(the probability of having A) + (the probability of having B)

• assume conditions are mutually exclusive and you can only have one at a time
• A or B situation

Question 25

what is the difference between statistical significance vs. clinical significance?

Answer 25

statistical significance just means that the data holds significance in terms of p-value, but a provider will want to know if the data is clinically significant and that requires clinical judgement

Question 26

what is the difference in abnormal in statistics and abnormal in medicine?

Answer 26

abnormal in statistics simply refers to what is unlikely (such as having extremely high intelligence) and abnormal in medicine means pathological

Question 27

what is the mean

Answer 27

obtained by adding up the numbers and dividing by the total number of numbers

Question 28

what is the median

Answer 28

the center number in the ordered sequence of data points

Question 29

what is the mode

Answer 29

the number that appears most often in the sequence

Question 30

What is it called when there is no mode? how about two modes? or three?

Answer 30

amodal; bimodal; trimodal

Question 31

How can outliers affect the mean?

Answer 31

the mean tends to move towards the direction of the outliers

Question 32

what is a trimmed mean?

Answer 32

the highest and lowest values are omitted, thus reducing the distorting effect of outliers

Question 33

What is a weighted mean?

Answer 33

a mean combined from several samples of different sizes

Question 34

what is an approximate mean

Answer 34

resembles the weighted mean, but is used where data points are in intervals

Question 35

what is geometric mean

Answer 35

summarizes change over time as the average ratio of change

Question 36

The mean, median, and mode are all considered to be forms of an ____

Answer 36

average, but each one may be useful in different situations

Question 37

what is the range

Answer 37

the difference between the highest and lowest values

Question 38

Explain the limitations of the range

Answer 38

similar ranges may correspond to very different sets of data; for example, one provider that sees a max of 60 patients a day and a minimum of 52 patients a day has a range of 8, so does a plastic surgeon who sees a minimum of 1 patient and maximum of 9. Same range but very different work loads.

Question 39

what is variance

Answer 39

a better way of describing the spread (like the range) in data; shows variability among the data points

Question 40

what is standard deviation

Answer 40

a measure of the amount of variation or dispersion of a set of values from the mean

Question 41

what is a z-score?

Answer 41

the number of standard deviations a data point (element) lies away from the mean

Question 42

what is the coefficient of variation

Answer 42

standard deviation divided by the mean; it is another way of looking at the scatter of data points around the mean