Educational Statistics:
             Very Brief History
   • Chevalier de Mėre’s gambling problems and Blaise Pascal’s 
    solutions (mid-1600s).
   • Abraham de Moivre’s publication (in English) of his Doctrine of 
    Chance in mid 1700s.
   • William Sealy Gossett’s development of the formula, in the early 
    1900s, for the standard error of the mean.
   • Development of the t-test, analysis of variance, and non-parametric 
    statistics in the first quarter of the 1900s.
        Educational Statistics:
        Statistical Terms and Vocabulary
   •Statistics: a set of methods, procedures and rules 
    for organizing, summarizing, and interpreting 
    information.
    – This is a general definition.
    – Later, a distinction between statistics and parameters 
     will be made.
    – Here, it would be better to speak of statistical 
     methods.
            Educational Statistics:
           Statistical Terms and Vocabulary
    • Use of symbols in statistics
      – Statisticians (and statistical books) use symbols as shorthands for complex 
       concepts and constructs.
      – Symbols are typically either Arabic or Greek letters.
      – For example:
        • µ  (the Greek letter, mu) typically represents the mean (arithmetic average) of a 
         set of values.
        • σ  (the lower-case Greek letter, sigma) typically represents the standard 
         deviation of a set of values.
        • For a list of Greek symbols and their meanings in statistics, see Symbols 
         and Notation under General links to a variety of sources in the Table of 
         Contents.
        Educational Statistics:
        Statistical Terms and Vocabulary
   Three Types of statistical methods:
   • Descriptive statistics: methods used to summarize, 
    organize, and simplify data.
   • Exploratory statistics: methods for carefully examining 
    data prior to using more complicated statistical 
    procedures.
   • Inferential statistics: methods that allow us to make 
    generalizations about populations based on data obtained 
    from samples.
        Educational Statistics:
        Statistical Terms and Vocabulary
   Population vs Sample
   • Population: all members of a particular group (e.g., all 
    Appstate freshman, all males over the age of 21, all of the 
    schools in NC).
   • Sample: a subgroup of a population that is usually 
    assumed to be representative of the population (e.g., 10 
    Appstate freshman selected at random).