Statistics 1 mindmap

Statistics 1 mindmap

1. Types of Data

   • Numerical
     • Discrete
       • eg. goals, number of desks
     • Continuous
       • eg. Height, Speed, time
   • Categorical
     • Ordinal
       • eg. opinion scales, types of houses
     • Nominal
       • countres, Colours, Sports

2. Bivariate

   • 2 paired items
     • weight & height

3. Univariate

   • 1 item of data

4. Population (eg. the whole group)

   • Sampling (eg Some o the population)
     • Avoid bias (eg not properly selected sample)
       • 1. Not representative (outside bus stop for sampling how people travel to work
       • 2.Not correct Population (just 6th years)
       • 3. Failure to respond
       • 4.Dishonest answers
     • Simple Random Sample (everyone has an equal chance)
       • Names out of hat/ random number generator/ random number table

5. Collecting Data

   • Surveys (eg Postal, telephone, observation)
   • Experiment (eg drug testing)
   • Questionaire- (multiple response, opinion scales, avoiding bias)
   • Primary (collected by individual using it)
     • Advantages 1. exactly what you need. 2. You know from who. 3. you know how it was collected
     • Disadvantages 1. expensive. 2. Slow
   • Secondary (someone else collected data, ie. internet)
     • Advantages 1. cheap,2. easy to obtain
     • Disadvantages - 1. may be out of date. 2. not be exactly what was required