Types of data

• Quantitative data - numerical data

  • Easier to analyse
  • Oversimplifies behaviour

  Qualitative data - expressed in words

  • Represents complexities
  • Less easy to analyse
• Primary data - collected for the purpose of the investigation.

  • Fits the job
  • Requires time and effort

  Secondary data - collected by someone other than the person who is conducting the research.

  • Inexpensive
  • Quality may be poor

  Meta analysis - type of secondary data that involves combining data from a larger number of studies.

  • Increases validity of conclusions
  • Publication bias
• Measures of central tendency

  Mean - arithmetic average

  • sensitive
  • can be unrepresentative

  Median - middle value

  • unaffected by extreme scores
  • less sensitive than mean

  Mode - most common value

  • relevant to categorical data
  • overly simple measure
• Measures of dispersion

  Range - difference between the highest and lowest value.

  • easy to calculate
  • does not account for the distribution of the scores

  Standard deviation - measure of the average spread around the mean.

  • more precise than range
  • may be misleading