data analysis

Question 1

What is data?

Answer 1

the information that has been gathered from a sample in a study

Question 2

What are the 4 types of data?

Answer 2

1. Qualitative
2. Quantitative
3. Primary
4. Secondary

Question 3

What are the 3 levels of data?

Answer 3

1. Nominal
2. Ordinal
3. Interval

Question 4

What is nominal data?

Answer 4

Category / frequency e.g., tally

Question 5

What is Ordinal data?

Answer 5

ranking / ratings (an order)

Question 6

What is interval data?

Answer 6

precise measurements

Question 7

What are descriptive statistics?

Answer 7

a way of summarising and describing data

Question 8

What are the two types of statistics?

Answer 8

descriptive and inferential

Question 9

What are the two types of descriptive statistics?

Answer 9

measures of central tendency and measures of dispersion

Question 10

What do measures of central tendency do?

Answer 10

summarise the data and give a typical value and middle of the data set

Question 11

What are the 3 measures of central tendency?

Answer 11

mean, mode, and median

Question 12

How do you calculate the mean?

Answer 12

add up all the values and then divide sum by however many values there are

Question 13

Calculate the mean of:
7,7,5,7,4,5,8,37

Answer 13

10

Question 14

What is the weakness of using a mean?

Answer 14

data can be skewed or distorted by outliers making the typical score misleading

Question 15

What is the strength of using a mean?

Answer 15

as it takes all values into account it is more likely to be representative

Question 16

How do you calculate the median?

Answer 16

arranging all values into ascending order (lowest to highest) and then using the middle value

Question 17

What do you do if there are two numbers left when trying to find the median?

Answer 17

add both values together and divide by 2

Question 18

Calculate the median of:
4,5,5,7,7,7,8,37

Answer 18

7

Question 19

What is a strength of using the median?

Answer 19

an appropriate measure if there are outliers - not distorted

Question 20

What is a weakness of using the median?

Answer 20

less representative as it does not take all values into account

Question 21

How do you calculate the mode?

Answer 21

the most frequently occurring value

Question 22

Why is the mode different from other measures of central tendancy?

Answer 22

there can be no mode or more than one mode (bimodal or trimodal)

Question 23

Calculate the mode:
7,7,5,7,4,5,8,37

Answer 23

7

Question 24

What is the weakness of the mode?

Answer 24

at times does not indicate the typical data score

Question 25

What is the strength of the mode?

Answer 25

only measure that can be used for nominal category data (no calculations required)

Question 26

What do measures of dispersion do?

Answer 26

summarise the data but indicate the spread of values - the extent to which scores deviate from the mean

Question 27

What are the 3 types of dispersion?

Answer 27

range, variation, and standard deviation

Question 28

What is the range?

Answer 28

subtracting the lowest value from the highest value

Question 29

Calculate the range 13,14,15,16,17

Answer 29

4

Question 30

What is the preferred range?

Answer 30

0 (smaller)

Question 31

Why is a smaller range preferred?

Answer 31

indicates values are closer to the mean and so more similar

Question 32

What is the strength of the range?

Answer 32

very useful as it is a simple measure to calculate the spread

Question 33

What is the weakness of the range?

Answer 33

it is completely determined by outliers and therefore can easily be distorted

Question 34

What are the measures of dispersion that are not effected by outliers?

Answer 34

variance and standard deviation

Question 35

What do variance and standard deviation do?

Answer 35

calculates the distance of every value from the mean and averages it

Question 36

How many formulas are there to calculate standard deviation?

Answer 36

2

Question 37

Why are there two formulas?

Answer 37

one for population and one for sample

Question 38

What formula do you use most often?

Answer 38

sample

Question 39

What are the steps to calculate standard deviation?

Answer 39

1- Calculate mean 2- take each value away from the mean 3- square each value 4- add squared totals together 5- divide squared total by sample size (-1) 6- square root

Question 40

What is the strength of standard deviation?

Answer 40

not affected by outliers (unlike range) and take all values into account (representative)

Question 41

What do inferential statistic do?

Answer 41

test for significance - make sure any relationship / difference is definite and not due to chance

Question 42

What is the significance level most often used in psychology?

Answer 42

95% (P≤0.05)

Question 43

What is the significance level for severe and important investigations?

Answer 43

99% (P≤0.01)

Question 44

What are the two types of errors when analysing data?

Answer 44

Type 1 and Type 2

Question 45

What is a type one error?

Answer 45

- saying you have found something when you have not - incorrectly rejecting a true null hypothesis - accepting a false alternate hypothesis

Question 46

What is a type 2 error?

Answer 46

- saying you haven't found something when you have - accepting a false null (failure to reject it) - rejecting a true alternate hypothesis