Presenting Data

Question 1

Bar Chart

Answer 1

• This shows data in the form of categories (nominal data) which the researcher wants to compare.
  > Categories should be placed on the x axis (in any order).
  > The columns of bar charts should be the same width and separated by a space. The use of a space illustrates that the variable on the X axis is not continuous
• ‘discrete data’

Question 2

Histogram

Answer 2

• Used for continuous data (interval data) - rather than bar charts
  > Continuous scores or values should be placed equally along the X axis.
  > Frequency of these values is shown on the Y axis
  > No spaces between the bars since the data is continuous
  > Each bar should be the same width.

Question 3

Frequency Polygon

Answer 3

• Dot is drawn where the data need to represented.
  > Then joined up in a straight, continuous line
  > Highlights the continuous nature of the variable on the x axis
  > Main advantage of using a frequency polygon over a histogram is that more than one data set can be represented at a time.

Question 4

Scattergram

Answer 4

• Used to visually represent correlational data.

> Infer positive/negative correlation

Question 5

Normal Distributions

Answer 5

• Bell Curve /’’’’’\

> mean, mode and median all at midpoint + Standard Deviation

Question 6

A skewed distribution

Answer 6

• Doesn’t have most people in the middle
• Caused by extreme values (anomalies/outliers).

> Left- skewed = the long tail is on the left side of the peak /’’’| -(Mean Right-skewed = the long tail is on the right side of the peak |’’’\ -(Mode