Presentation of quantitative data

• Characteristics of tables

  • Raw scores displayed in columns and rows.
  • A summary paragraph is beneath the table to explain the findings and draw conclusions.
• Characteristics of bar charts

  • Categories (discrete data) are placed along the x-axis and frequency on the y-axis.
  • The height of each column represents the frequency of that item.
• Characteristic of histograms

  • Bars touch each other.
  • Data is continuous.
  • There is a true zero.
  • X-axis is made up of equal-sized intervals.
• Characteristics of scattergrams

  • Used for correlational analysis.
  • Each dot represents one pair of related data.
  • Illustrates strength and direction of correlation.
  • The data on birth axes must be continuous.
• Normal distribution

  • Symmetrical, bell-shaped curve.
  • Most items are in the middle of the curve with very few at the extreme ends.
  • The mean, median, and mode all occupy the same mid-point of the curve.
• Skewed distributions

  Distributions that lean to one side or the other because most items are either at the lower or upper end of the distribution.
• Negative skew

  • Most of the distribution is concentrated towards the right of the graph, resulting in a long tail on the left.
  • The mode is the highest point of the peak, the median comes next, and the mean is dragged across to the left.
• Positive skew

  • Most distribution is concentrated towards the left of the graph, resulting in a long tail on the right.
  • The mode is the highest point of the peak, the median comes next, and the mean is dragged across to the right.