Population and Sample

• Population


  It refers to the complete group of people being the target population of a study.
• Sample


  It refers to a part of a population as representatives to generalize the conclusion
• Nursing students


  If your target population are college students in a certain university, what can be an example of your sample?
• Sampling Techniques


  These are methods used to select a group of individuals or items from a larger population for the purpose of research.
• Sampling techniques can be divided in two categories.
• There are five types of random sampling or probability sampling: simple random sampling, stratified random sampling, cluster sampling, systematic random sampling, and multi-stage sampling.
• There are four types of non-probability sampling or non-random sampling: convenience sampling, snowball sampling, judgement or purposive, and quota sampling.
• Random sampling involves selecting individuals in a way that there is an equal chance of each individual being chosen.
• Random sampling 


  This category of sampling is achieved through selection methods like lottery.
• Random sampling provides a representative sample when the population is homogenous and well-defined.
• Simple Random Sampling


  This type of sampling is the most basic random sampling wherein each element of the population has an equal probability of being selected.
• Simple Random Sampling

  This type of sampling is usually represented by unique identification numbers written on equal-sized and shaped papers, and selected using the lottery method.
• Simple Random Sampling

  In this type of sampling, numbers are selected to decide which elements are included as the sample.
• Steps when using the simple random sampling:

  1. Using the Slovin’s Formula
  2. Assigning the numbers to each member of the population
  3. Writing the numbers on the pieces of paper having the same size and shape.
  4. Putting all the folded pieces of paper in a bowl or box.
  5. Selecting the pieces of paper from the bowl randomly.
• Systematic Random Sampling 


  This type of sampling uses a list of the population and selecting individuals based on the kth consistent intervals.
• When using the systematic random sampling, to get the kth interval, divide the population size by the sample size.
• Systematic Random Sampling


  This type of sampling is less time-consuming than simple random sampling and can be easily implemented with ordered lists.
• Steps when using the systematic random sampling:

  1. Giving out random numbers
  2. Getting the kth interval
  3. Choosing a random start
• Stratified Random Sampling


  This type of sampling involves dividing the population into subgroups or strata based on certain characteristics.
• Stratified Random Sampling


  This type of sampling involves randomly selecting from each stratum in proportion to their representation in the population.
• Stratified Random Sampling ensures representation of various subgroups within the population, leading to increased precision and accuracy of estimates.
• Cluster Sampling


  This type of sampling involves dividing the population into clusters or groups based on their geographic location.
• What are the two types of stratified random sampling

  Proportionate and Disproportionate
• Multi-stage sampling


  What technique is used when clusters are too large and there is a need for a second set of smaller clusters to be taken from the original clusters.
• Convenience Sampling


  This type of sampling involves selecting individuals that are readily available and accessible to the researcher.
• Convenience sampling is often used for its convenience and ease of implementation, but may lead to biased results due to the non-random selection.
• Convenience sampling is commonly used when time and resources are limited.
• Purposive or Judgement Sampling


  This type of sampling involves selecting individuals based on a specific criteria by the researcher’s judgement or purpose of the study.
• Purposive or Judgement Sampling


  This type of sampling is commonly used when the researchers seek to include participants who possess characteristics relevant to the study.
• Purposive or Judgement Sampling


  This type of sampling is used in qualitative research, case studies, or when studying hard-to-reach populations.
• Snowball Sampling


  This type of sampling involves participants who meet the criteria of the study and asking them to refer for other potential participant.
• Snowball Sampling


  This type of sampling is often used when studying hidden or stigmatized populations where traditional methods of sampling are impractical.
• Snowball sampling is used for accessing hard to reach populations.
• Quota Sampling


  This type of sampling involves choosing individuals according to quotas, or categories that represent specific characteristics of the researcher’s study.
• Quota Sampling


  This type of sampling occurs when the researcher is interested in a particular strata.
• What are the three most common measures of central tendency?

  Mean, Median, Mode
• Mean


  It is the most widely used measure of central tendency.
• Mean 


  This measure of central of tendency is computed by adding all the values in the data set and dividing the it by the number of values.
• Median


  This measure of central tendency is known as the middle value.
• Mode


  This is a type of measure that refers to the value that occurs most often.