Chapter #1

Chapter #1

1. Statistics

   • the science of conducting studies to collect, rganize, summerize, analyze and draw conclusions from data
   • Variable
     • characteristic or attribute that can assume different values
   • Data
     • value that a variable can assume
     • Qualitative: Categorical
     • Quantitative: Numerical, Can be ranked
       • Discrete Countable Ex: 5, 29, 8000, etc.
       • Continuous: Can be Decimals Ex: 2.59. 312.1 ect.
   • Population
     • consists of all subjects that are studied
   • Sample
     • subset of the population
   • Descriptive statistics
     • consists of the collection, organization, summarization and presentation of data
   • Inferential statistics
     • consists of generalizing from samples of popuations, performing estimations and hypothesis tests determining relationships among variables, and making predictions

2. Levels of Measurement

   • Nominal
     • Categorical (names)
   • Ordinal
     • Nominal. plus can be ranked (order)
   • Interval
     • ordinal. plus intervals are consistent
   • ratio
     • interval, plus ratios are consistent, true zero

3. Samples of Techniques

   • Random
     • random number generator
   • systematic
     • Every K^th subject
   • stratified
     • divide population into layers
   • Cluster
     • Use intact groups
   • Convenient
     • Mall surveys
   • Sampling Error
     • Sample Vs. Population

4. Experimental Design

   • Observational Study
     • Observes and tries to draw conclusions based on the observation
   • Confounding Variable
     • influences the dependent variable but cannot be separated from the independant variable