First, consider deliberate thinking. Deliberate thinking is relatively slow, rule-based and explicit; a contemplative process of weighing pros and cons, gathering scientific or statistical evidence. It would appear that this makes for pretty solid decision-making.
Jul 24, 2015. Outliers increase the standard deviation. Mean is most affected by outliers, since all values in a sample are given the same weight when calculating mean. A value that is far removed from the mean is going to likely skew your results and increase the standard deviation. Say you have five values: 2, 1, 2, 1.5, and 2.1.
Usually, the presence of an outlier indicates some sort of problem. This can be a case which does not fit the model under study, or an error in measurement. Outliers are often easy to spot in histograms. For example, the point on the far left in the above figure is an outlier. A convenient definition of a outlier is a point which falls more than 1.5 times the interquartile range above the third quartile or below the first quartile. Outliers can also occur when comparing relationships between two sets of data.