Distribution Curves
Variables such as height, weight, shoe size, exam results, and IQ scores – all tend to show normal distribution when plotted on graphs.
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 In Psychology, this information can help researchers make assumptions about the way in which populations are distributed.
Normal Distribution Curves
= arrangement of data that is symmetrical and forms a bell-shaped pattern.
​The mean, median and/or mode all are shown in the centre at the highest peak.
3 characteristics of normal distributions 
  • Symmetry at the mean value
  • The curve end points or “tails” meet the x-axis
  • The shape of the curve should be bell-shaped.
Can you apply these 3 characteristics to a graph AND then say what this says about the population / sample?
Skewed Distribution Curves
Skewed distribution curves are called skewed when it is not symmetrical at the mean (or median or mode) point. A skew can be positive or negative.
OCR's Distribution Curve Workbook 
​can be found here