Graphical Representation

Question 1

Graphs

Answer 1

• pictorial presentation of data
• way of summarising the data in the pictorial form, in the most effective and clear way as possible, so that the person reading them cab indertand what they show

Question 2

Graphs should have?

Answer 2

• clear title
• labelled axis inclu units
• appropriate scale
• title stating type of graph and what it shows
• so that the data could not be misrepresented

Question 3

Bar chart: features

Answer 3

• categories/ items go on X axis
• Y axis = frequency
• GAPS BETWEEN EACH BAR (indicates lack of continuity)

Question 4

Bar chart: justification of use?

Answer 4

• use for nominal data (frequency/ categories)
• data that is not continuous/ discrete
• can also be used when drawing a graph to compare ‘means’ from 2 different conditions

Question 5

Bar chart purpose?

Answer 5

Shows differences in the cateogries of data

Question 6

What is discrete data?

Answer 6

Refers to seperate or distinct measures or groups such as categories

Question 7

Histogram features?

Answer 7

• y axis = frequency (*NOT FREQUENCY DENSITY)
• X axis = continuous (0-10, 11-20)
• the area within the bars must be proportional to the frequencies represented
• NO GAPS between bars (data sets r continuous)

Question 8

Histogram justification of use?

Answer 8

Used where dsta is continous (ordinal, interval, ratio data) e.g. 1-50 scores on a depression scale
- can use line graph for ordinal, ratio, interval too

Question 9

Histogram: purpose?

Answer 9

Shows how grouped data is spread across the continuous scale

Question 10

line graph: features?

Answer 10

• essentially all the same rules apply as histogram
• Y axis = frequency and must start at 0
• X axis = continuous
• dots connected with a line

Question 11

line graph justification of use?

Answer 11

used where data is continuous (ratio, ordinal, interval)

Question 12

line graphs purpose?

Answer 12

• usually a measure of time (ratio data)

- shows how a variable changes (often over time)

Question 13

pie chart features?

Answer 13

• each slice represents a fraction/ proportion of the total

- calculate by working out the appropriate proportion out of 360 degrees

Question 14

EQUATION for degrees (pie chart)

Answer 14

(proportion/ frequency divided by total number of items) x 360

Question 15

pie chart justification of use?

Answer 15

use to represent frequency data

- nominal data

Question 16

pie chart purpose?

Answer 16

show how measures from distinct groups show as a proportion of the total scores

Question 17

scatter graph features?

Answer 17

• each axis represents one co-variable
• each dot represents each ppt
• the scatter of dots indicated the degree of correlation between the co-variables

Question 18

scatter graph - justification of use?

Answer 18

• use for correlational research

Question 19

scatter graphs purpose?

Answer 19

shows associations or relationships between co-variables

Question 20

DEFINITION: bar chart?

Answer 20

suitable chart for data that is not continuous i.e. has no particular order - usually represents categories or nominal data

Question 21

DEFINITION: histogram?

Answer 21

similar to a bar chart, but the data displayed in the x axis is continuous rather than in categories. there should be no gaps between bars

Question 22

DEFINITION: line graph?

Answer 22

like a histogram, as it displays continuous data on the x axis and there is a dot to mark the top of each bar and the dots are connected with a line

Question 23

DEFINITION: scatter graph?

Answer 23

a graph showing the correlation between 2 co variables represented by dots

Question 24

DEFINITION: pie chart?

Answer 24

a way of representing the proportions of data as a fraction or percentage of the whole

Question 25

DEFINITION: normal distribution?

Answer 25

a symmetrical bell shaped frequency distribution with most scores clustered to the mid point

Question 26

DEFINITION: positive skewed distribution?

Answer 26

a display of the frequency of distribution where most of the scores are bunched towards the left with the mode left of the mean as the mean is affected by extreme scores

Question 27

DEFINITION: skewed distribution?

Answer 27

distribution of data has one tail longer than another, showing there are a number of extreme scores on one side or another of the mean

Question 28

distribution definition?

Answer 28

refers to how the ppts scores are spread out over the measuring scale

Question 29

normal distribution features?

Answer 29

- freq distrubution that has a classic bell shaped curve - mean, median, mode are all in the exact mid point - most scores will be closely distributed near the midpoint - distribution of frequency is symmetrical around mid point - dispersion of scores around midpoint is consistent and can be expressed in standard deviations - x axis = frequency y = item of interest

Question 30

normal distribution justification of use?

Answer 30

- for data that is evenly distributed | - justification = same mean, median, mode

Question 31

normal distribution examples?

Answer 31

weight, height, shoe size

Question 32

if one group has a much higher SD than another, ?

Answer 32

this means ,most of the scores are more spread out and are more likely influenced by ppt variables rather than the characteristics of the condition

Question 33

skewed distribution justification of use?

Answer 33

used for populations where scores are not equally distributed around mean - used when lots of extreme values to one side of the mid score

Question 34

PosItive skew?

Answer 34

rIght - majority of scores have low values - tail end of high scores - so mean is to the right of mode and median justification: order of mean median mode e. g. depression scale scores

Question 35

nEgative skew?

Answer 35

lEft - majority of scores have high values - tail end of low scores - mean is to left of the mode and median - e.g. a very easy maths test

Question 36

one eye on exam?

Answer 36

- never say correlation/ relationship in a conclusion - unless its a scatter graph / correlation study - use words such as difference/ majority/ most least - never use "significant" in a conclusion, unless it is CLEARLY STATED that the results have been put thru a statistical analysis