Setting up your BI 345 Blog

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• Include your username (as much of it as you can)
• Include "anselm"
• Include "bi345"
• Example from Google Blogger: http://bi345jpitocchanselm.blogspot.com/

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Introduction - Definitions

Definitions of Statistics - 3 levels

1. Discipline of statistics - area of study within Mathematics
2. Numerical summary of data (e.g., mean, standard deviation)
3. Results of a statistical test (e.g., observed t or F value result from a statistical test)

History of Statistics

History of Statistics

Major events

• Ancient Greece - ideas but nothing else
• 17th Century - affairs of state (statistics gets its name)
• 18th and 19th Century -development of normal curve and distribution
• Early 20th Century - Pearson (father of modern statistics), Gossett and Fisher
• Later 20th Century - most of the modern tests are developed by biologists, psychologists and economists
• Invention of the computer provides computational power and further development of new techniques

Properties of Data and Variable in Statistics

Properties of Data and Variable in Statistics

All scientific data in Science - measurements in the metric system

• Volume (ml)
• Distance (m)
• Weight (g)
• Temperature ('C)

Types of Data and Variables

• Ratio
• Interval
• Ordinal
• Nominal
• Continuous
• Discrete

 Measurement Concepts

• Accuracy
• Precision
• Significant digits
• Rounding rules

Hypothesis testing

Hypothesis Testing

Scientific Hypotheses and the Scientific Method

• Science - search for natural explanations of natural phenonmena
• Methodology - Scientific Method (hypothetico-deductive method)

Steps of the scientific method

1. Search for information
2. Ask Questions
3. Develop testable hypotheses
4. Test hypothesis - design experiment
5. Collect data
6. Analyze data
7. Interpret results
8. Answer question from above
9. Present the results - oral, written

Statistical Hypotheses and Statistical tests

• 2 hypotheses for each statistical test
•  Null hypothesis - statement of no differences
• Alternate hypothesis - statement of an existing difference
• Two-tailed and one-tailed variations