Midterm 1

Question 1

Sample

Answer 1

smaller representation of the whole population

Question 2

Population

Answer 2

pool of individuals from which a sample is drawn

Question 3

Explain the difference between parameters and statistics

Answer 3

Parameters describe populations, statistics describe samples

Question 4

Random sample

Answer 4

everyone in the population has a equal chance of being chosen

Question 5

Convenience sample

Answer 5

People that are easier to access by the researcher are chosen

Question 6

Bias

Answer 6

prejudiced results and strays away from the accurate value

Question 7

Error

Answer 7

inaccurate results which is usually always present in a sample

Question 8

Sampling error

Answer 8

randomness, statistical noise (when you increase sample size, sampling error decreases)

Question 9

Sampling bias

Answer 9

when some members of the population are more likely to be chosen than others

Question 10

Measurement error

Answer 10

Difference between the observed value and unobserved value

Question 11

Measurement bias

Answer 11

When I collect data

Question 12

Relate sampling and measurement bias to the concepts of internal and external validity

Answer 12

How well you control confound variables
How well your results reflect the entire population

Question 13

Confidence Interval

Answer 13

Probability that a parameter falls between a set of values for a certain proportion

Question 14

Explain the effect of increased sample size on confidence intervals.

Answer 14

Decreases the width of confidence interval as it decreases the standard error

Question 15

Continuous

Answer 15

On a scale, changes over time

Question 15

Mean

Answer 15

average

Question 15

Categorical

Answer 15

discrete categories ex. sex/snowboard

Question 15

Ordinal

Answer 15

rank order

Question 16

Median

Answer 16

middle number

Question 17

Mode

Answer 17

number that occurs the most

Question 18

When are mean and median the same

Answer 18

normal distribution and if data is symmetrical

Question 19

What is used as central tendency if data is skewed

Answer 19

median

Question 20

Describe the probable sample effect on the range of a variable

Answer 20

The greater your sample size the larger the range

Question 21

Explain how quantiles can be used to measure variance

Answer 21

Used to calculate interquartile range (variability around the median)
Calculated as the third quartile - first quartile

Question 22

Explain the probable sample effect on the interquartile range

Answer 22

As sample size increases, variance decreases

Question 23

Explain how standard deviation is calculated

Answer 23

The square root of variance by determining each points deviation from the mean

Question 24

Coefficient of Variation

Answer 24

standard deviation over mean of the population to show variability

Question 25

Confidence interval on the mean

Answer 25

provides a upper and lower limit, and tells us how much uncertainty there is

Question 26

Explain what a standard error on the mean measures

Answer 26

Measures the discrepancy between the sample mean and population mean

Question 27

Describe what sample size effects have on the SEM

Answer 27

As sample size increases SEM decreases

Question 28

Identify three assumptions made in calculating SEM

Answer 28

Random sample Independent observations Accurate data not biased

Question 29

Explain what t measures

Answer 29

How closely distribution of data measures distribution predicted under the null hypothesis

Question 30

Correctly define what a p value measures

Answer 30

The probability of obtaining observed results assuming that null hypothesis is true

Question 31

Effect size

Answer 31

how meaningful the relationship between variables was

Question 32

NHST

Answer 32

non-hypothesis significant testing (testing to check significance between two variables assuming the null hypothesis is true)

Question 33

type 1 error

Answer 33

rejecting the null hypothesis when its true

Question 34

Type 2 error:

Answer 34

not rejecting the null hypothesis when its false

Question 35

Residual

Answer 35

difference between observed and expected values

Question 36

Assumptions of a Pearson product-moment correlation

Answer 36

Random sample Independent observations Linear relationship No outliers normal distribution

Question 37

What a coefficient of correlation measures

Answer 37

Direction and strength of linear relationship between two variables