LEVELS OF MEASUREMENT

• What are statistical tests used for?

  used to see if results are due to chance. determine whether a difference or a correlation is significant
• what are the 3 criteria for choosing a statistical test?

  looking for a difference or a correlation?

  is experimental design related or unrelated?

  what is the level of measurement?
• what are the 3 levels of measurement?

  nominal data

  ordinal data

  interval data
• what does the level of measurement tell you?

  how precise the measurement is
• what is nominal data?

  simple categories

  very basic and the least precise method, get no additional detail beyond which category the person belongs to
• what is ordinal data?


  placed in order with subjective or unknown intervals eg happiness score on a scale of 1-10

  more precise than nominal as you can understand where scores sit in relation to each other, still lacks some precision as measure is subjective
• what is interval data?

  measured using a scale with units of equal size

  very precise measurement as it tells you exactly where a score sits