Soc 5 random sampling methods

  1. Systematic sampling (with a random
    • elements of the population are put into
    • a list and then every k th element in the list is chosen (systematically) for inclusion. To ensure against bias, the researcher selects the first individual at random.
  2. PROs and CONs
    Systematic sampling (with a random start)
    • PRO: simplicity in randomization, POP is evenly sampled
    • CON: can interact with a periodic trait w/in POP (ie, may only have Hispanics and not generalizable to the entire population)
  3. Stratified random sampling
    initially categorize subjects into groups (age, socioeconomic status, gender, etc.); then randomly select from the different strata (which do not include any overlaps).
  4. PROS and CONS
    Stratified random sampling
    • PRO: used for studying a particular population. Warrants more precise statistical outcomes.
    • CON: may require more administrative effort than a simple random sample.
  5. Cluster random sampling
    • (used when simple random sampling is almost impossible due to size of population)
    • select groups (church), then select individual subjects from each through choice of random sampling.
    • Usually population elements already grouped into subpopulations and lists of those subpopulations may already exist or can be easily created.
  6. PROS and CONS
    Cluster random sampling
    PRO: Quick, cheap and easy.

    • CON: least representative of population for probability sampling.
    • Possibly over or underrepresented cluster in terms of characteristics that can skew results of the study.
    • Possibly high sampling error caused by the
    • limited clusters included in the sample, which leaves a significant proportion of the population unsampled.
Card Set
Soc 5 random sampling methods