introduction

Question 1

a variable is

Answer 1

a set of characteristics that describe ana spect of participants in research e.g. gender, blood pressure

Question 2

two main types of variable

Answer 2

categorical

quantitative

Question 3

categorical data

Answer 3

usually facts rather than numerical

- participants are classified into categories

Question 4

two types of categorical

Answer 4

nominal and ordinal

Question 5

nominal variables

Answer 5

unordered labelled characteristics

• binary variables (just two categories)
• observations can be assigned a code in the form of a number where the numbers are simply labels
• can count but not order

Question 6

example of a nominal variable

Answer 6

blood group: A, B, AB, O

Question 7

ordinal variable

Answer 7

• small set of ordered categories
• categories might be labels or numbers
• obs can be ranked
  e. g. house numbers and swimming level

Question 8

example of ordinal variable

Answer 8

disease severity: none, mild, mod, sevre

Question 9

categorical data are recorded as

Answer 9

numbers which represent specific categories e.g.

Gender: (1) male, (2) female

Question 10

quantitative variables

Answer 10

valies have quantitative meaning. The higher the number the more there is of the concept
e.g. the tiger number for age means you’re older

Question 11

quantitative variables are also known as

Answer 11

continuous

Question 12

distribution def

Answer 12

refers to the diff values that occur and the frequency with which they occur for a given variable

Question 13

categorical data can be described using

Answer 13

• frequency tables

- bar charts

Question 14

how to describe quanitiaitve data

Answer 14

average. variation, symmetry

Question 15

average

Answer 15

what value characterises the middle of distribution

Question 16

variation

Answer 16

speed, dispersion, how far apart the values are from each other

Question 17

symmetry

Answer 17

for each person that has a score below the average is there a corresponding person with the score the same distance about the avergae

Question 18

types of average

Answer 18

mean, median mode

Question 19

mean

Answer 19

sum of soccer divided by the number of scores

Question 20

median

Answer 20

rank the scores in order and the median is the value that divides the data in 2

Question 21

mode

Answer 21

the most frequently occurring score

Question 22

when is mode not useful

Answer 22

in quantitive data-there may be more than one mode, each value in study might appear only once- mode could be low/high

Question 23

disadvantages of the range

Answer 23

• sensitive to unusually extreme values (outliers)

- dependent on sample size- as sample size gets larger the range cannot get smaller, but it can get larger.

Question 24

symmetry of quantitative variable

Answer 24

o Examples of symmetrically distributed date:
• 1,2,3,4,5
• -2,0,2
• 3,3,10,17,17

Question 25

graphical summary of quantitative data

Answer 25

• histograms
• dotplots
• box and whisker plot

Question 26

what is the definition of standard deviation

Answer 26

the spread of data around the mean

- the average difference between the spare and the mean

Question 27

standard error

Answer 27

The standard error is the estimated standard deviation or measure of variability in the sampling distribution of a statistic. A low standard error means there is relatively less spread in the sampling distribution. The standard error indicates the likely accuracy of the sample mean as compared with the population mean.

Question 28

the lower the standard deviation

Answer 28

the more accurate the data

Question 29

Inter-quartile rane

Answer 29

IQR spans the middle 50% of score i.e. range between the lower and upper quartiles

Question 30

lower quartile

Answer 30

is the value below which 1/4 of socks lie

1/4(n+1)th score (25th percentile)

Question 31

upper quartile

Answer 31

is the value above which 1/4 of score lie

3/4(n+1)th score (75th percentile)

Question 32

histogram

Answer 32

a graph where the heights of the rectangular bars/bins are used to indicate the relative frequency which with values in specific ranges occur

Question 33

for histograms to show a clear shape, at least…

Answer 33

50 observations are required

Question 34

symmetrical histogram

Answer 34

bell curve

Question 35

positive skewed histogram

Answer 35

skewed to the left

Question 36

negative skewed histogram

Answer 36

skewed to the right

Question 37

bimodal histogram

Answer 37

will have two peaks

Question 38

uniform histogram

Answer 38

rectangle shape

Question 39

dot plot

Answer 39

is like a histogram that is turned back to front and flipped on its side

Question 40

in a dot plot each dot represents

Answer 40

an Ob

Question 41

the length of the brass of dot plots indicate

Answer 41

how common the value is

Question 42

when are dot plot especially useful

Answer 42

when plotting distributions for small sample sizes

Question 43

The Box and whisker lot graph indicated

Answer 43

• median
• lowe quartile
• upper quartile
• rage that contains most values
• outliers

Question 44

outliers

Answer 44

extreme observations which are either low or high values

Question 45

in box and whiskers what would represent a positive skew

Answer 45

if the top part of the box is thicker than the bottom part and top whisker is slightly longer than the bottom

Question 46

what sort of summary statistics should be used for symmetric data (bell curve)

Answer 46

summary statistics that make use of all the data

Question 47

what sort of summary statistics should be used for asymmetric data (positive or negatively skewed)

Answer 47

summary stats that are insensitive to extreme values