data analysis

Question 1

what is the degrees of freedom calculation

Answer 1

df=(r-1)x(c-1)
r- rows
c- columns

Question 2

what is qualitative data

Answer 2

non numerical data expressed in words

Question 3

advantages and disadvantages of qualitative data

Answer 3

+ rich in detail
- difficult to analyse

Question 4

what is quantitative data

Answer 4

numerical data

Question 5

advantages and disadvantages of quantitative data

Answer 5

+ easier to analyse and identify patterns
- less detail

Question 6

what is primary data

Answer 6

first hand data collected for the purpose of the investigation

Question 7

what is secondary data

Answer 7

collected by someone other than the person conducting the research

Question 8

advantages and disadvantages of primary data

Answer 8

+ directly relevant data= more valid
- requires more time and effort
- ethical consideration needing to be taken into account

Question 9

advantages and disadvantages of secondary data

Answer 9

+ minimal effort and inexpensive and less time consuming
- unknown quality or relevance= less valid

Question 10

what is nominal data

Answer 10

qualitative values usually tallied, frequency not able to rank
eg gender weather ethnicity marital status

Question 11

what is ordinal data

Answer 11

scaled or ranked data
eg a score from 1-5

Question 12

what is interval/ratio data

Answer 12

ranked data with equal measurement intervals
eg temperature time bank balance

Question 13

what does measure of central tendency mean

Answer 13

a statistic that summarizes a set of data with a single value that represents the middle or center of the distribution

Question 14

what does a measure of dispersion mean

Answer 14

the spread of data around a central value

Question 15

examples of central tendency measures

Answer 15

mean, mode, median

Question 16

examples of dispersion measures

Answer 16

range, standard deviation

Question 17

what is standard deviation

Answer 17

a statistical measure that shows how spread out a set of scores are around the mean

Question 18

advantages and disadvantages of using a mean

Answer 18

+ shows the average
+ more representative
- extreme values can cause a difference

Question 19

advantages and disadvantages of using a mode

Answer 19

+ easier to calculate
- doesnt take into account the extreme values

Question 20

advantages and disadvantages of using a median

Answer 20

+ unaffected by extreme values
+ easy to calculate
- doesnt take into account extreme values so less sensitive

Question 21

advantages and disadvantages of using a range

Answer 21

+ easy to calculate
- dont know how spread out the scores are in a number set

Question 22

advantages and disadvantages of using standard deviation

Answer 22

+ more precise
+ more accurate picture of all the data
- can be distorted by outliers

Question 23

how to calculate mean

Answer 23

add all numbers up and divide by total amount of numbers

Question 24

how to calculate mode

Answer 24

the most frequent value

Question 25

how to calculate median

Answer 25

the middle number in the data after they have be ranked ordered

Question 26

how to calculate range

Answer 26

minus the biggest number from smallest

Question 27

why would you use a bar chart

Answer 27

for nominal data

Question 28

why would you use a histogram

Answer 28

continuous data (has no gaps)

Question 29

what does a scatter graph show

Answer 29

relationship between data

Question 30

what is distribution

Answer 30

overall pattern of data seen in a graph

Question 31

how do you know its negative distribution

Answer 31

the mean is before the mode

Question 32

how do you know its positive distribution

Answer 32

the mean is after the mode

Question 33

what is a significance level

Answer 33

a measure of strength of evidence

Question 34

what is teh usual significance level

Answer 34

p<0.05

Question 35

when would psychologists use a harder significance level

Answer 35

when they want to challenge research

Question 36

what does p<0.05 mean

Answer 36

95% sure the data is correct

Question 37

what is a type 1 error

Answer 37

(false positive) reject the null hypothesis when shouldve accepted it

Question 38

what is a type 2 error

Answer 38

(false negative) accepting a null hypothesis when shouldve rejected it

Question 39

how can we remove the chances of a type 1 error

Answer 39

make the significance level stricter but it may increase type 2 error

Question 40

how can we reduce a type 1 and 2 error

Answer 40

increase sample size

Question 41

what is the acronym for deciding which test

Answer 41

carrots should come mashed with swede under roast potatoes (chi squared sign test chi squared, mann whitney wilcoxon spearmans, unrelated t realated t pearsons)

Question 42

what are the steps on finding the critical value and if it is significant

Answer 42

1. directional or not hypothesis= one or two talied 2. use the df value and find number 3. use the information to see if the number should be equal or higher or lower 4. if matches information then it is significant

Question 43

what test is a directional hypothesis

Answer 43

one tailed

Question 44

what test is a non directional hypothesis

Answer 44

two tailed

Question 45

what are the steps to calculate sign test

Answer 45

1. state alternative or null hypothesis 2. represent each pair of data with + - 0 3. calculate value of s (number of less frequent sign) 4. look up critical value in the table using it and other pieces of data 5. compare critical and calculated value and follow rule given to you 6. accept/ reject hypothesis if the result is significant

Question 46

What main headings should a formal write up have

Answer 46

Title Abstract Introduction Method- design, materials, participants,procedure,ethical issues Results Discussion References Appendices

Question 47

What does an abstract on a formal write up include

Answer 47

aim of investigation, brief explanation and hypothesis

Question 48

What does an introduction in a formal write up include

Answer 48

Why you carried out investigation Background knowledge on the subject Overall aim of the study Hypothesis type

Question 49

What is included in the results section of a formal write up

Answer 49

Summary table and graph Basic statistics but not explained Justification of the statistical test used

Question 50

What is included in the discussion section of a formal write up

Answer 50

Explanation of results Comment on graph Note any possible sources of error Any corresponding modifications

Question 51

What is the order that referencing information has to go in

Answer 51

Author Year Title Edition Place Publisher