stats + scientific method

Question 1

what is discovery science

Answer 1

describing nature
qualitative data
observations

Question 2

what is hypothesis-based science

Answer 2

explaining nature
quantitative data
experiments

Question 3

steps of scientific method

Answer 3

1. make observations
2. ask questions
3. form a hypothesis
4. make a prediction
5. test prediction
6. interpret data
7. draw conclusions

Question 4

what does testing the prediction involve

Answer 4

plan experiments
perform experiments
collect data and analyze

Question 5

what is a theory

Answer 5

well-substantiated explanation for a set of verified hypotheses

Question 6

what is an independent variable

Answer 6

variable that is being manipulated
location

Question 7

what is a dependent variable

Answer 7

results from the change to the independent variable
presence of mutations

Question 8

what are the types of statistics

Answer 8

descriptive and inferential

Question 9

what are descriptive stats

Answer 9

central tendency
measure of variance

Question 10

what is central tendency

Answer 10

mode mean and median

Question 11

what is the mode

Answer 11

most common number in a set of numbers

Question 12

what is the median

Answer 12

the middle value in a set of numbers

Question 13

what are the measures of variance

Answer 13

variance and standard deviation

Question 14

what are inferential stats

Answer 14

error bar analysis
unpaired/independent t test

Question 15

what are the characteristics of a normal distribution

Answer 15

all central tendencies are the equal
bell shaped curve
most of the values and in the middle
curve is symmetrical

Question 16

what happens when the mean is standardized to zero

Answer 16

majority of points will be grouped in the middle

Question 17

what is variance

Answer 17

relative distance between data points and mean
S^2

Question 18

what is standard deviation

Answer 18

how far apart are the numbers in the sample
SD

Question 19

what is the main advantage of using standard deviation compared to variance

Answer 19

standard deviation is in the same units as the data points

Question 20

what is standard error

Answer 20

how accurate your results are compared to the population
SE

Question 21

what does having a higher S^2, SD or SE mean

Answer 21

there is more variability in the sample and we can be less confident in the results

Question 22

n < 10, gap is 2

Answer 22

likely significant, p is around 0.05

Question 23

n > 10, gap is 2

Answer 23

significant, p is around 0.01

Question 24

n > 10, gap is greater than 2

Answer 24

significant, p < 0.05

Question 25

n > 10, gap is 1

Answer 25

likely significant, p around 0.05

Question 26

n < 10, gap is greater than 2

Answer 26

significant, p < 0.05

Question 27

n < 10, gap is 1

Answer 27

not significant, p > 0.05

Question 28

gap is 0

Answer 28

not significant

Question 29

when can you not use an unpaired t test

Answer 29

before and after of the same group
no means
comparing more than two groups or only one

Question 30

t test steps

Answer 30

1. state hypotheses
2. write down data
3. write number of replicates
4. calculate means
5. calculate variance
6. calculate standard deviation
7. calculate t value
8. pick a significant value (0.05)
9. figure out if hypothesis is one or two tailed
10. find t critical
11. compare values

Question 31

p value > alpha

Answer 31

no significance

Question 32

alpha > p value

Answer 32

significant

Question 33

how does the hypothesis being two tailed affect the alpha value

Answer 33

alpha becomes 0.025 for each side

Question 34

t crit < t cal, negative one tailed

Answer 34

not significant

Question 35

t crit > t cal, positive one tailed

Answer 35

not significant

Question 36

t crit < t cal, positive one tailed

Answer 36

significant

Question 37

t crit > t cal, negative one tailed

Answer 37

significant

Question 38

t crit > t cal, two tailed

Answer 38

significant

Question 39

t crit < t cal, two tailed

Answer 39

significant