What is Statistics?

Statistics is a branch of mathematics dealing with the collection, organization, analysis, interpretation and presentation of data. In applying statistics to, for example, a scientific, industrial, or social problem, it is conventional to begin with a statistical population or a statistical model process to be studied. Populations can be diverse topics such as "all people living in a country" or "every atom composing a crystal". Statistics deals with all aspects of data including the planning of data collection in terms of the design of surveys and experiments

Wikipedia

Some Key Points

• Much of statistics works with probabilities and stochastic data (data affected by randomness)
• The word "statistics" refers both to the field of statistics and the numerical quantities it calculates
• Stochastic data is "randomly determined; having a random probability distribution or pattern that may be analyzed statistically but may not be predicted precisely."
• Hence mathematical probability theory provides a foundation for much of statistics
• Statistics often works with "incomplete data" -- that is data that has been sampled from a larger population
• There are two main branches of statistics: descriptive statistics and inferential statistics
• Descriptive statistics is often concerned with summarizing data
• Examples of inferential statistical measures include: mean, median, standard deviation, maximum, minimum, range, scatter plots, correlations
• Inferential statistics draws conclusions from data that subject to random variation
• Examples of inferential statistics are: opinion polling, t-test, anova, linear regression
• A robust and validated statistical model can be used to make justified predictions
• Scientific theories can be tested using inferential statistics
• In my experience, the lack of absolute certainty is challenging - it makes people uncomfortable