Univariate visualization
- interval and ratio variables


A bit of statistics



Average
•The „geographical centre“ of data
•sum of distances to lower values = sum of distances to higher values
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• movie rating 0-100 points
•Red dots: users evaluation
•Green dot: average value
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Median
•Value standing in the middle
•Half of data are lower, half higher
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Relation between mean and median



Standard deviation
standard deviation formula for population and sample
•How far are data from average
•Average speed 50 KMpH (30 miles)
•Because the car went whole time exactly 50 (sd=0)
•Because car went half of journey 30 and other half 70 (sd=20)
•Because car spent one hour in traffic jam and half hour went 150 (sd=70)
•higher deviation means higher variance

Other descriptive stats



Histogram



How to make histogram
•No need for any computation!
•Select column and click on histogram

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Highlighting mean
•=AVERAGE(column)
•= MEDIAN(column)
•Change of color mave to be done manually
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Box plot



•Avoid the usage of 3D versions
•They can be very misleading
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•Be carefull with ratio aspect
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•Always make titles, subtitles and labels as parsimonous as possible
•(parsimony means to be maximally simplistics and maximally informative simultaneously)
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