L2 | SAMPLING PROCEDURE AND SAMPLE

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Cards (32)

  • SAMPLE
    • portion or part of the population that is representative of the population
  • RESPONDENTS
    • individuals or groups of people who actively serve as sources of information during data collection.
  • SAMPLING
    • method or process of selecting respondents or people to answer questions meant to yield data for a research study
  • POPULATION
    • bigger group from where you choose the sample that possess some common characteristics
  • SAMPLING FRAME
    • to mean the list of the members of such population from where you will get the sample
  • PROBABILITY SAMPLING
    • every member of the population has a known chance of participating in the study.
  • NON-PROBABILITY SAMPLING
    • not each population member has a chance to participate in the study.
  • HISTORY OF SAMPLING
    • traced back to the early political activities of the Americans, in 1920 when Literary Digest did a pioneering survey about the American citizens’ favorite among the 1920 presidential candidates.
    • very first survey served as the impetus for the discovery by academic researchers of other sampling strategies 
    • categorized into two classes: 
    • probability sampling 
    • non-probability sampling. (Babbie 2013)
  • ADVANTAGES OF SAMPLING (BROWN, 2006)
    1. Makes the research of any type and size manageable
    2. Significantly saves the cost of the research
    3. Results in more accurate research findings
    4. Provides an opportunity to process the information in a more efficient way
    5. Accelerates the speed primary data collection (Dudovskiy, 2016)
  • PROBABILITY SAMPLING METHODS
    • Simple random sampling
    • Systematic random sampling
    • Stratified random sampling
    • Cluster random sampling
  • PROBABILITY SAMPLING METHODS
    • all the members of an entire population have a chance of being selected. 
    • also called as scientific sampling
    • commonly used in quantitative research.
  • SIMPLE RANDOM SAMPLING
    • all the members of the population are given an equal chance of being selected.
    • unbiased way of selection
    • samples are drawn by chance.
    • various ways of obtaining samples through simple random sampling (Treece & Treece, 1986)
    • roulette wheel
    • fishbowl method
    • use of table of random numbers.
  • FISHBOWL METHOD
    1. The sampling frame, or a list of all the subjects or elements of the population in question, should be prepared.
    2. All the names of the subjects or elements should be written down on strips of paper (one name per strip of paper).
    3. The strips of paper with the listed names are then placed in a bowl or container.
    4. Samples can be drawn as desired.
  • SYSTEMATIC RANDOM SAMPLING
    • selecting every nth element of a population, 
    • (e.g every 5th, 8th, 9th, or 11th element until the desired sample size is reached.)
  • STRATIFIED RANDOM SAMPLING
    • The population is divided into different strata (groups), and then the sampling follows. 
    • Age, gender, and educational qualifications are some possible criteria used to divide a population into strata.
  • CLUSTER RANDOM SAMPLING
    • used in large-scale studies
  • CLUSTERS
    • representative samples of the population as a whole. 
    • After it’s established, a simple random sample of the clusters is drawn and the members of the chosen clusters are sampled.
    • Sampling procedures are difficult and time-consuming.
  • NON-PROBABILITY SAMPLING METHODS
    • CONVENIENCE SAMPLING
    • PURPOSIVE SAMPLING
    • QUOTA SAMPLING
    • VOLUNTEER SAMPLING
    • SNOWBALL SAMPLING
  • NON-PROBABILITY SAMPLING METHODS
    • disregards random selection of subjects.
    • subjects are chosen based on their availability or the purpose of the study, and in some cases, on the sole discretion of the researcher.
    • not a scientific way of selecting respondents
    • commonly used in qualitative research.
  • CONVENIENCE SAMPLING
    • choosing respondents at the convenience of the researcher
    • also called accidental or incidental sampling.
  • PURPOSIVE SAMPLING
    • involves handpicking subjects, usually to suit very specific intentions. 
    • also called judgmental sampling.
  • QUOTA SAMPLING
    • somewhat similar to stratified sampling, 
    • The population is divided into strata, and the researcher deliberately sets specific proportions in the sample, whether or not the resulting proportion is reflective of the total population. 
    • Commonly done to ensure the inclusion of a particular segment of the population.
  • VOLUNTEER SAMPLING
    • people who self-select into the survey. 
    • Often, these folks have a strong interest in the main topic of the survey.
  • SNOWBALL SAMPLING
    • does not give a specific set of samples
    • achieved by asking a participant to suggest someone else who might be willing or appropriate for the study.
    • true for a study involving an unspecified group of people.
    • Dealing with varied groups of people such as street children, drug dependents, gang members, informal settlers, and street vendors. 
  • STRATEGIES TO OBTAIN A QUALITY SAMPLE
    1. Focus on the study
    2. Find a representative sample
    3. Determine a recruitment strategy
    4. Consult with the community to identify and recruit potential participants
    5. Avoid selection bias
    6. Do not give up after the first attempt to recruit a potential participant
    7. Allow flexibility in the process
  • FOCUS ON THE STUDY
    • Make certain that the research question is feasible and the study answers a question with clear variables.
  • FIND A REPRESENTATIVE SAMPLE
    • Determine the necessary addition and omission criteria for the study population such that findings can exactly generalize or identify results to the target group.
  • DETERMINE A RECRUITMENT STRATEGY
    • Spell out a plan to identify and enroll study participants. 
    • may entail screening or establishing criteria for number, location, and sampling method.
  • CONSULT WITH THE COMMUNITY TO IDENTIFY AND RECRUIT POTENTIAL PARTICIPANTS
    • Study existing infrastructure to discover venues of contacting suitable samples. 
    • Researchers must also be considerate and receptive to the recommendation of local experts and leaders.
  • AVOID SELECTION BIAS
    • also essential to recruit a fitting comparison group.
  • DO NOT GIVE UP AFTER THE FIRST ATTEMPT TO RECRUIT A POTENTIAL PARTICIPANT
    • Follow-up using various communication strategies, including personal, written, or electronic messaging. 
    • Importance of personal contact should not be undervalued.
  • ALLOW FLEXIBILITY IN THE PROCESS
    • If existing recruitment strategies are resulting in inadequate enrollment of participants or modifications are made in criteria of participants, the solution may be to change the sampling plan.