Statistics

Statistics

1. Data

   • - consists of information coming from observations , counts, measurements or responses
   • Population
     • Parameter
       • - a numerical description of a population characteristic
     • Census
       • - count of an entire population
   • Sample
     • - subset, or part of a population
     • Statistics
       • - numerical description of sample charecteristic
     • Sampling techniques
       • Random Sample
         • Simple Random Sample
       • Stratified Sample
         • - when members of the population are divided into 2 or more subsets called strata, that are similar in characteristics. A sample is then randomly picked from each strata
       • Cluster Sampling
       • Systematic Sample
     • Sample Size
       • - the number of subjects
     • Sampling Error
       • - the difference between the results of a sample and those of the population
   • Types of Data
     • Qualitative
       • - attributes, labels, or nonnumerical entries
       • Nominal
         • - (qualitative only) data at this level are categorized using names, labels, or qualities
     • Quantitative
       • - consists of numerical  measurements or counts
       • Ratio
         • - (quantitative only) Data is similar to Interval level with the added property of an inherent 0.
       • Interval Level
         • - (quantitative only) Data can be ordered, and meaningful differences between data entries can be calculated
     • Ordinal
       • - (can be qualitative or quantitative) data at this level can be arranged, in order, or ranked, but differences between data entries are not meaningful 
   • Data Collection
     • Observational Study
     • Preform and Experiment
       • - a treatment is applied to part of the population and responses are observed. Another part of the population  is used as a control group which is given a placebo
       • Confounding Variable
         • - occurs when an experimenter cannot tell the difference between the effects of different factors on a variable. 
       • Blinding
         • Double Blinding
           • - neither the experimenter or the test groups know which is the placebo treatment
       • Randomization
         • - a process of randomly assigning subjects to different treatment groups
         • Completely Randomized Design
           • - where subjects are assigned to different treatment groups through random selection.
         • Blocks
           • - groups of subjects with similar characteristics
       • Replication
         • - the repetition of an experiment under the same or similar conditions
     • Using a simulation
       • - the use of mathematical or model to reproduce the conditions of a situation or process. ( normally with computers). Usually they depict situations that are dangerous to test in real life.  
     • Use a survey
       • - an investigation of one or more characteristics of a population. ( mostly asking questions and recording responses

2. Inferential Stats

   • - using a sample to draw conclusions about a population. A basic tool used in this branch is probability.
   • Conclusion

3. Descriptive Stats

   • - organization, summarization, and display of data
   • Data Summerization
     • Orginization