WST 133

• Data


  Facts and figures collected, analyzed, and summarized for presentation and interpretation

  
• Statistics


  The art and science of collecting, analyzing, presenting, and interpreting data

  
• Statistics is more information, more understandable, and more organized compared to raw data

  
• For a particular study, data are the facts and figures collected, analyzed, and summarized for presentation and interpretation

  
• All the data collected in a particular study are referred to as the data set
• Elements


  The entities (individuals/objects) on which data are collected
• Variable


  A characteristic of interest of the elements
• Observation


  The set of measurements obtained for a particular element
• The table shows the means of transport used by people attending different types of educational institutions in 2001
• Means of transport used by people attending an educational institution

  • On foot
  • By bicycle
  • By motorcycle
  • By car as a driver
  • By car as a passenger
  • By mini-bus/taxi
  • By bus
  • By train
  • Other
• Types of educational institutions

  • Pre-school
  • School
  • College
  • Technikon
  • University
  • Adult education centre
  • Other
• Data versus Statistics
• Table 2: Means of transport used by people attending an educational institution by type of institution (numbers), 2001
• Data: Facts & figures collected, analysed and summarized for presentation and interpretation
• Statistics: The art and science of collection, analyzing, presenting and interpreting data

  
• Elements: Entities on which data is collected
• Variables: Characteristics of interest for the elements
• Observation: A set of measurements obtained for a particular element
• Variable: A characteristic of interest regarding the elements
• When collecting data ask yourself: What is the exact definition of each variable? In what unit of measurement is each variable recorded?
• Data set: A collection of data
• Statistics: Numbers that summarize data
• Climate of provincial capitals
• Variables


  • Temperature(oC)
  • Hours of sunshine
  • Rainfall(mm)
  • Number of rain days
  • Annual rainfall (mm)
• Elements


  • Eastern Cape
  • Free State
  • Gauteng
  • KwaZulu-Natal
  • Mpumalanga
  • Bisho
  • Bloemfontein
  • Johannesburg
  • Pietermaritzburg
  • Nelspruit
• Statistics


  The process of using data obtained from a sample to make estimates or test hypotheses regarding the population
• Assume


  To take for granted or without proof
• Descriptive Statistics


  Tabular, graphical, and numerical summaries of data
• Inferential Statistics


  The process of using data obtained from a sample to make estimates or test hypotheses regarding the population
• The process of using data obtained from a sample to make estimates or test hypotheses regarding the population
• Describe


  To give an account of in words
• Express


  To put (thoughts, feelings, etc.) into words
• Explain


  To make (something) clear or understandable
• Illustrate


  To clarify or explain by use of examples, analogy, etc.
• Portray


  To depict or represent in words
• Population: Is the set of ALL elements of interest in a particular study
• Sample: Is a subset of the population
• The purpose of this study was to examine how sap-flow is affected by different variables
• The objective of statistics is to make an inference about a population based on information contained in a sample from that population and to provide an associated measure of goodness for the inference
• Different types of writing can sometimes be distinguished by the lengths of the word used