Descriptive Statistics

• descriptive statistics


  -mathematical summaries of the data set; they can either focus on various forms of average or on the spread of data
• what are the two types of descriptive statistics?

  -measures of central tendency; these provide an average score from within the data set. It includes mean, median and mode-measures of dispersion; these provide an insight into how spread out the data was. The closer the scores are, the smaller the dispersion will be. Lower/smaller dispersions imply more reliable data with fewer anomalies. Measures of dispersion include range and standard deviation.
• measures of central tendency

  meanmedianmode
• mean


  averageadd up all the numbers, then divide by the amount of number there areweaknesses- it is influenced by an anomalous result + it may produce a 'non sense' value not provided in the original set of data
• median


  the mid point in a set of data that has been placed in orderstrengths- it is not influenced by an anomalous result + it can always be found when using ordinal or above level data
• mode


  the most common score in a set of datastrength- it can be used for data measured on a nominal scaleweakness- there may be more than one result, or no result at all if results are varied
• measures of dispersion


  rangestandard deviation
• range


  The range is a value which shows the spread of data, representing the difference between the lowest and highest scores
• standard deviation


  a value which represents the amount of variation of results from the mean score. It gives you an idea of how far the majority of the results are from the mean.