population and sampling

• population


  the large group of individuals who share specific characteristics that a researcher is interested in studying - doesn't refer to the general population so is sometimes referred to as the general population so is sometimes referred to as the target population
• sampling


  populations usually too large to study all of it so we select a sample from it that is representative of everyone - sample drawn from population will be representative of target population so generalisation of findings becomes possible (giving high population validity)
• bias and generalisation


  bias - under representing or over representing certain groups within a sample - e.g. too many younger people or too few males

  generalisation - extent to which findings from a specific sample can be applied to the population - made possible if sample is representative of the population