Biology 2244A/B Lecture Notes - Lecture 4: Statistical Inference, Descriptive Statistics, Statistical Hypothesis Testing
12 Dec 2017
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Descriptive statistics: conducting studies to collect, summarize, analyze, and draw conclusions from data vs. inferential statistics: generalization from samples to populations, estimation, hypothesis testing, and prediction making. Population: the entire group of individuals about which we want information. Qualitative (categorical) variable: places individuals into one of several groups/categories. Ordinal variable: information can be ranked in order. Ex. (cid:498)do you strongly disagree, disagree, agree or strongly disagree? (cid:499) Ex. (cid:884)(cid:882) degrees is not (cid:498)twice as hot(cid:499) as (cid:883)(cid:882) degrees. Quantitative variable: takes numerical values, can do arithmetic with. Interval data: know exact differences between values, but cannot ratio them. Ratio data: data with a natural 0 point, can make ratios. Ex. the tree is twice as tall as the house. Continuous variable: can take any real numerical value over an interval. Technically infinite range of possible values, just have to use infinitely more precise measuring tools. Discrete variable: only take a limited, finite number of values.
