From my lecture note at university #4 (Modeling with statistics)

At the session #4 today, the topic was “data variance”.

The concept of variance is often forgotten or ignored when you capture and describe the data tendency.


I have not seen any person who was able to appropriately answer to my question “How would you explain about average?”  You may find the average acting as a balancing point in the chart above. You may reach this conclusion only when you think about the data variance together.


Standard deviation (today’s main topic) is a statistical tool to measure the variance. You may also find the variance visually in the charts above but it would be a bit hard to explain the difference of the variance by just showing such charts, where you can utilize the index such as standard deviation.

Also I announced the first assingment for the workshop #1 in November. Each team is required to find two data sets and to highlight any insightful contrasts by using average, standard deviation etc.


Good luck everyone!


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