1.2 AO2: MEAN- Uses all the data but one
rogue number can distort it. MEDIAN: Not
as badly affected by rogue scores but
not good when using small data sets.
MODE: Used for when wanting to know
how often something happens but
sometimes data doesn't have a most
frequent value.
2 MEASURES OF DISPERSION
2.1 RANGE: The DISTANCE
between the HIGHEST and
LOWEST values in the data and
is used with MODE or MEDIAN.
2.1.1 AO2: Easy to calculate and takes in
extreme scores but ignores most of the
data and may reflect the true distribution.
2.2 SEMI-INTERQUARTILE RANGE:
Remove TOP and BOTTOM quarter
of data and calculate the RANGE and
is used with a MEDIAN.
2.2.1 AO2: Gives a better idea of
distribution and not distorted by
extreme scores but 50% of the
numbers are ignored and laborious
to calculate.
2.3 STANDARD
DEVIATION: A
calculation that
tells us the
AVERAGE
'DISTANCE
FROM THE
MEAN' of the data
points and is
used with a
MEAN.
2.3.1 AO2: Representative of the data as
it uses every data point but tricky to
calculate by hand.
3 TABLES
3.1 RAW DATA is the numbers
collected in the research before
anything is done to them. The rule
with tables is to make them as
clear and easy to read as
possible.
3.1.1 In the exam you could be asked
to show your understanding of
tables by interpreting one.
4 GRAPHS
4.1 BAR CHARTS: Numbers of
things in different categories. It
has gaps between category
bars, frequency number on
y-axis and categories on x-axis
referring to discrete categories.
4.2 HISTOGRAM: Same as
BAR CHART except the
x-axis measures a
constantly changing scale
(e.g. mass or height). It has
a continuous variable on
the x-axis and there are no
gaps between the bars.
4.3 FREQUENCY
POLYGON: Same as
HISTOGRAM but
instead of bars a line is
drawn joining the
middle points of the top
of each bar. It has a
continuous variable on
the x-axis and its just a
line (no bars).
4.4 SCATTERGRAPH: Values for the same individual for two
different variables, each plotted on one axis. It is used to depict
correlation and it can show positive, egative or zero correlatios
as well as 'Curvilinear relationships.
5 PRESENTING QUALITATIVE DATA
5.1 As Qualitative data is concerned with opinions,
you need to present it by organising the data into
categories of response. Then this can be put into
tables and graphs.