RESSAMPLING QUIZ

• Sampling

  The process of selecting units (e.g. people, organizations) from a population of interest so that by studying the sample we may fairly generalize our results back to the population from which they were chosen
• Sample


  A smaller group of members of a population selected to represent the population
• Census study


  When the entire population will be sufficiently small, and the researcher can include the entire population in the study
• Advantages of sampling

  • Reduces cost
  • Reduces time
  • Provides greater accuracy
  • Allows study of inaccessible populations
  • Provides greater speed
• Sampling method

  A procedure for selecting sample members from a population
• How to execute sampling method

  1. Define target population

  2. Select appropriate target population
• Categories of sampling methods

  • Probability sampling
  • Non-probability sampling
• Probability sampling


  • Every member of the population has a known chance of participating in the study
• Non-probability sampling


  • Sampling group members are selected on non-random manner, therefore not each population member has a chance to participate in the study
• Probability sampling methods


  • Simple random sampling
  • Systematic random sampling
  • Stratified random sampling
  • Cluster sampling
  • Multi-stage sampling
• Simple random sampling


  The purest form of sampling under the probability approach since it provides equal chances of being picked for each member of the target population
• Systematic random sampling


  A list of every member of the population is created, the researcher randomly selects the first sample element from the first k element on the population list, then selects every kth element on the list
• Stratified random sampling


  The population is divided into groups, based on some characteristic, then within each group, a probability sample is selected
• Cluster sampling


  Every member of the population is assigned to one, and only one group, a sample of clusters is chosen, using a probability method, only individuals within sampled clusters are surveyed
• Multi-stage sampling


  The researcher selects a sample by using combinations of different sampling methods
• Non-probability sampling methods


  • Quota sampling
  • Purposive sampling
  • Volunteer sampling
  • Convenience sampling
  • Snowball sampling
• Quota sampling


  Identifies strata like stratified sampling, but it also uses a convenience sampling approach as the researcher will be the one to choose the necessary number of participants per stratum
• Purposive sampling


  The researcher selects participants according to the criteria he/she has set
• Purposive sampling


  • Advantages: most cost-effective and time-effective, may be the only appropriate method available if there are only limited no. of primary data sources who can contribute to the study

  Disadvantages: vulnerability to errors in judgment by researcher, low level of reliability and high level of bias, inability to generalize research findings
• Volunteer sampling


  Made up of people who self-select into the survey, often these folks have a strong interest in the main topic of the survey
• Volunteer sampling


  • Advantages: not time consuming, minimal effort required

  Disadvantages: volunteer bias, results cannot be generalize
• Convenience sampling


  Made up of people who are easy to reach, used when there are only a few available members of the target population who can become the participants in the survey
• Snowball sampling


  Used when the desired sample characteristic is rare, it may be extremely difficult or cost prohibitive to locate the respondents, achieved by asking a participant to suggest someone else who might be willing or appropriate for the study
• Slovin's formula


  A formula used to determine sample size
• Online sample size calculator


  A tool used to determine sample size
• Adherence to the sample size is important - participants less than the sample size leads to low representativeness of the target population, participants over the sample size may cause a diminished rate of enhancement in the precision of the survey outcomes