Biological Statistics

Question 1

measurement variable

Answer 1

variable that is measured

Question 2

nominal variable

Answer 2

variable that is classified by observations into categories

Question 3

null hypothesis (H₀)

Answer 3

hypothesis that states that there is no relationship or effect between variables

Question 4

alternative hypothesis (H₁)

Answer 4

hypothesis which states there is relationship or effect between variables

Question 5

confounding variables

Answer 5

variable that influences both the dependent variable and independent variable

unable to be easily controlled

Question 6

mean (X)

Answer 6

average

sum of all values divided by number of values in set

Question 7

function of mean

Answer 7

determination of central tendency

Question 8

median

Answer 8

single value in middle of sorted list from lowest value to highest value

Question 9

mode

Answer 9

most frequent value in set of data

most useful with imprecise measurements

Question 10

unimodal set

Answer 10

set of data with only 1 mode

Question 11

bimodal set

Answer 11

set of data with 2 modes

Question 12

range

Answer 12

difference between maximum and minimum of set of data

Question 13

standard deviation (σ)

Answer 13

measure of amount of variation or dispersion of set of values in relation to mean

can be used either as measure of variation within set of data or reliability of measurement

Question 14

error bars

Answer 14

graphical representation of variability of data

able to show range of data, range of precision of measurement, or standard deviation

Question 15

t-test

Answer 15

statistical hypothesis test used to compare means of 2 different samples

Question 16

result of t-test

Answer 16

p-value

Question 17

p-value

P

Answer 17

value which indicates probability that null hypothesis is correct

Question 18

significance of P ≥ 0.05

Answer 18

no statistical significance

indicates null hypothesis cannot be rejected

Question 19

significance of P < 0.05

Answer 19

statistical significance

Question 20

significance of P < 0.01

Answer 20

high statistical significance

indicates null hypothesis can be rejected

Question 21

analysis of variance

ANOVA

Answer 21

statistical hypothesis test used to determine presence of statistically significant difference between means of 2+ samples

Question 22

result of analysis of variance

Answer 22

F-statistic (used to find p-value)

Question 23

correlation

Answer 23

strength and direction of relationship between values

Question 24

Pearson correlation coefficient (r)

Answer 24

statistic that measures linear correlation between 2 variables

Question 25

range of Pearson correlation coefficient

Answer 25

between -1 and +1

Question 26

significance of r = -1

Answer 26

perfect negative correlation between 2 variables

Question 27

significance of r = 0

Answer 27

no correlation between 2 variables

Question 28

significance of r = +1

Answer 28

perfect positive correlation between 2 variables

Question 29

chi-squared test

χ² test

Answer 29

statistical hypothesis test used to determine presence of statistically significant difference between expected values and observed values