• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The Advantages and Disadvantages of Quota Sampling Compared to Random Sampling

Extracts from this document...


The Advantages and Disadvantages of Quota Sampling Compared to Random Sampling


Quota sampling is a non-probability sampling method, compared to random sampling methods, which are known as probability sampling methods. Examples of probability methods are stratifying sampling, cluster sampling, systematic sampling and simple random sampling. When a sample needs to be taken from a population, the issue of which type of sampling method to use arises; probability or non-probability. Since we are looking at specifically quota sampling, we need to define it. Quota sampling involves stratifying a population into mutually exclusive sub-groups, as if using the stratified sampling method. However, the difference is, in quota sampling, judgement is used instead of randomness to select units from each stratum. The number of sampling units chosen from each stratum is based on proportion. Random sampling is defined as when every unit in the population has a probability of being chosen. For a random sample to be carried out, there also needs to be a sampling frame.

Advantages of Quota Sampling

Although quota sampling is criticised heavily by academics, it does have its advantages. The biggest case for it is that is incredibly cheap to carry out. Travel

...read more.


(Moser & Stuart, 1953).

We have to also consider the possibility of bias erupting within the quotas at an individual level, leading to misrepresentations of the population. Take for instance; there is a quota for over 60 year olds. If the interviewer only finds people who range from 60 years old to around 65, then there is no representation of people who much older than 65 (Moser & Stuart, 1953).

Another example may be that the interviewer doesn’t like to travel to certain places, therefore only interviews people from a certain area, leading to selection bias in the sample. Random sampling doesn’t have this problem; “Random selection is the only selection mechanism in large-n studies that automatically guarantees the absence of selection bias (Epstein & King, 2002).”

Quota sampling also has the problem of non-response bias, a form of selection bias (selection bias is a non-sampling error). If somebody refuses to be a part of a study, then quota sampling allows the interviewer to go and find the next person who is willing, which results in data that is not wholly representative of the population. The reason for this is, that non-respondents probably have certain characteristics, and because the data obtained from the sample will not represent them at all (it will only be representative of respondents)

...read more.


(Moser & Stuart, 1953).

To conclude, there is never going to be a complete dismissal of a particular sampling method. Quota sampling has no theoretical structure; however practicality outweighs its negatives. If a researcher is looking for, “results derived from theoretically safe sampling methods,” then it is safe to say that quota sampling is out of the question (Moser & Stuart, 1953). If there are time and cost constraints to a researcher, then quota sampling can be convenient.



Epstein, L & King, G. (2002). The Rules of Inference. University of Chicago Law Review. 69 (winter), p1-209.

FAO Corporate Document Respository.  Sampling in Marketing Research. Available: http://www.fao.org/docrep/w3241e/w3241e08.htm. Last accessed 6th December 2010.

Lyman Ott, Mendenhall, Scheaffer, (2006). Elementary Survey Sampling. 6th ed. Canada: Thomson.

Moser & Stuart. (1953). An Experimental Study of Quota Sampling. Journal of the Royal Statistical Society. 116 (4), p412-413 & p387-340.

Tansey, O. (2007). Process Tracing and Elite Interviewing: A Case for Non-Probability Sampling. PS: Political Science & Politics. 40 (4), p770.

...read more.

This student written piece of work is one of many that can be found in our University Degree Statistics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Statistics essays

  1. Research Methods.

    While quantitative research is being more objective, qualitative research tends to have more subjective interpretation and mass detail for later analysis. Moreover, procedure is emphasized in quantitative study, replication and other tests of reliability become easier. Nevertheless, the measures of qualitative research may be taken to make research more reliable

  2. Why are longitudinal studies desirable and why are they difficult to undertake?

    It has been argued that missing data represents a problem for two main reasons. For example, it has been proved that item non response data can lead to a huge amount of loss of available sample size for data analysis.

  1. Quantitive Methods - questions and answers

    What is the probability that it receives no 'hits' for a given two minute interval? ? = average number of hits per 2 minutes = = 4 P (0) = = = 0.0183 2. What is the probability that it receives exactly 3 'hits' for a given two minute interval?

  2. Does the data indicate that the revised (one week) forecast is significantly more accurate ...

    From Statistical Table 5, with v = 6 + 5 = 11, tcrit=2.201 As calculated previously, A=0.1126, B=0.0823, and pooled standard deviation of sample equals to ==0.0211 tcalc = tcalc = = 2.593 Therefore, tcalc tcrit H0 There is significant difference between the outputs of the two filters.

  1. Explaining Research Methods Used by Social Scientists.

    These interviews can also be formal or informal. Questionnaires are almost all in the form of a written interview and the questions are usually pre-set. The advantages are that the questions can be open ended or multiple choice. A large sample is needed to make their conclusions useful and so could be more representative of the public making them more convincing.

  2. Using Statistical Methods to Investigate the Seashore Habitat of Shellfish and Flora + Fauna

    Another method was stratified sampling. These involved measuring a whole area and then collect fractions of data from every part of the area. This would probably be the most accurate way to collect my data but it is extremely time consuming for a whole area of rocky beach.

  1. How statistical interpretation can cause data to appear misleading

    "Data can be presented in three forms: text, tables and figures" (Williams and Wragg (d), 2004 p.102). Figures are used to establish trends and patterns, although they can be very misleading if not interpreted incorrectly; regularly the title is not specific to the results in the figure and so the

  2. Hypothesis method

    Even when choosing a probability level of 95%, there is always a 5% chance that one rejects the null hypothesis when it was actually correct. This is called Type I error, represented by the Greek letter ?. It is possible to err in the opposite way if one fails to reject the null hypothesis when it is, in fact, incorrect.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work