presentation of quanitative data

Question 1

name the tables/graphs

Answer 1

• summarising data in a table
• bar charts
• histograms
• scattergrams

Question 2

name the distributions

Answer 2

• normal distribution
• skewed distribution

Question 3

describe summarising data in a table

Answer 3

• summary table
• when tables appearing results section of report they aren’t raw scores, but have been converted to descriptive characteristics
• summary paragraph included beneath to explain numbers & draw conclusions

Question 4

describe bar charts

Answer 4

• used when data is divided into categories (discrete data)
• categories occupy x-axis
• frequency/amount of each category occupy y-axis
• bars are separated

Question 5

describe histograms

Answer 5

• bars touch each other
• shows x-axis is continuous data
• x-axis made up of equal sized intervals of single category
• y-axis represents frequency within each interval

Question 6

describe scattergrams

Answer 6

• don’t depict differences but instead associations between co-variables
• either of co-variables occupy x-axis & the other on the y-axis

Question 7

describe a normal distribution

Answer 7

• when measuring certain variables (eg. height of certain people), frequency of measurements should form bell-shaped curve
• symmetrical
• most people/items located in middle area of curve with few people at extreme ends
• mean, median & mode all occupy same midpoint
• ‘tails’ of curve (extend outwards) never touch x-axis (never reach 0) as more extreme scores always theoretically possible

Question 8

describe skewed distributions

Answer 8

• distributions which appear to lean to one side or the other

1. positive skew
   - most distribution concentrated towards left
   - long tail on right
   - mode remains at highest point of peak, median comes next & the mean is dragged across towards the ‘tail’
2. negative skew
   - bulk of scores concentrated on right
   - long tail on left
   - mean pulled to left, mode dissecting highest peak & median in middle