Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Looking at Data Measurement, time plots, outliers and other mysteries revealed! Graphing Data …. A Geller-Huchra map showing the distribution of distant galaxies - this map (and others like it) have transformed our understanding of the large-scale structure of the universe Different ways of presenting the devastating data on HIV-Aids in Africa A “picture” of our active sun – sunspot data since 1750 Perhaps one of the most important graphs in history! Getting to know the language… Individuals and Variables An individual is a object described by a datum A variable is a characteristic of an individual Example: the trees in a forest would define the individuals. The caliper (diameter) of the trees would be a variable. The height or distance from a lake etc etc would be other variables. Variables and Distributions… Variables can be: Categorical Quantitative A Distribution is the range of values that a variable can take Different ways to graph data… Stemplots Histograms Time series Measurement… In stats you must always be aware of what you are measuring and how you are measuring (ie – what instrument is being used). Measurement always entails error which implies variation in repeated measurements. Example: look at ex 1.3 Outliers… Compare Mark McGwire’s home run record with the variation in light output from the star IY Ursa Majoris Are there any outliers in either? Some suggestions… Read over summary on pages 21-22 and review as needed Try Section 1.1 Exercises: 1.7, 1.9, 1.17, 1.31