topic 6 - measurement and evaluation of human performance

• Error bars


  Graphical representation of the variability of data
• Standard deviation


  a computed measure of how much scores vary around the mean score
• medium variability


  Small st dev shows data is close to the mean value

  
• low variability


  large st dev shows that there is a wide spread around the mean

  
• coefficient of variation


  the ratio of the standard deviation to the mean
• t-test


  a statistical test used to evaluate the size and significance of the difference between two means
• t-value


  a ratio of the difference between the two sample means and the standard error
• p-value


  The probability level which forms basis for deciding if results are statistically significant (not due to chance).
• >0.05


  not reliable too much difference
• <0.05


  statistically significant p value and reliable
• corellational study


  Two variables have a relationship but not necessarily a cause and effect one
• r value


  The correlation coefficient that ranges from -1.0 to +1.0. The closer it is to 0, the less two variables are related.
• R-squared value


  Coefficient of determination

  
  

  Ranges from 0% to 100%