CH1

CH1

1. Types of statistics

   • Descriptive statistics: Graphical and numerical methods used to describe, organize and summarize data
   • Inferential statistics: Techniques and methods used to analyze a small, specific set of data to draw a conclusion about a large, more general collection of data

2. Terms

   • Population: The entire collection of individuals or objects to be considered or studied
   • Sample: A subset of the entire population.
   • Variable: A characteristic of an individual or object in a population of interest.
   • Observational study
   • Experimental study
   • Simple Random Sample (SRS)

3. Statistics and probability

   • Statistics: Information about a sample is used to answer questions concerning a population
   • Probability: information about the population is used to answer questions about sample

4. Process of Claim

   • Step 1 Claim: This is a statement of what we assume to be true.
   • Step 2 Experiment: To check the claim, we conduct a relevant experiment.
   • Step 3 Likelihood: We will use many techniques to determine whether the experimental outcome is a reasonable observation (subject to reasonable variability) or a rare occurrence.
   • Step 4 Conclusion: If the outcome is reasonable, then we cannot doubt the claim. If the outcome is rare, we disregard the lucky alternative and question the claim.

5. Types of Bias

   • Nonresponse bias: The individuals who are selected for the SRS do not count for some reason.
   • Self-selection bias: This is when the individual chooses to be included in the sample and not randomly selected to be in the sample.