Section 1 - Learning from data - created from Mind Map

Seite 1

Types of variable

Qualitative data - take values from a set of categories

Quantitative data - take values on a numerical scale

Data sets

Nominal - no natural order

Ordinal - natural order

e.g. colour, address

e.g. degree classification, place in a competition

Continuous

Discrete

Univariate

Multivariate

Describing distributions

Graphs

Statistics

Boxplots

Histograms - show the frequencu with which observations of QUANTITATIVE variable fall in specified intervals

Scatter Plots

Empirical Distribution Function - show the proportion of observation that fall below a specified value (uses the indicator function.)

Quantile-quantile plot - uses order statistics and gives a comparison of two distributions

Location - describes where on the numerical scale the data tends to fall

Shape - whether a distribution is symmetric or not

Scale - describes how far the data is spread across the numerical scale

Sample statistic - any quantity calculated from a sample

Mean

Median - (resistant)

Mode

Quantiles - uses order statistics!

Product moment correlation co-efficient

Yule-Kendall statistic

Positive/Negative skew

Standard Deviation

Inter-quartile range

Variance

Range

Association

Graphically

Numerically

Scatter plot

Covariance

Correlation

Section 1 -

Learning from data