Quantitative Research Solutions |
The aim of quantitative research is to determine how one thing (a variable) affects another in a population. Quantitative research designs are either descriptive (subjects measured once) or experimental (subjects measured before and after a treatment).
Keywords: Reduction, control, precision, measurable
Report statistical analysis.
Basic element of analysis is numbers
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THE SAMPLE
You almost always have to work with a sample of subjects rather than the full population. But people are interested in the population, not your sample. To generalize from the sample to the population, the sample has to be representative of the population. The safest way to ensure that it is representative is to use a random selection procedure. You can also use a stratified random sampling procedure, to make sure that you have proportional representation of population subgroups (e.g. sexes, races, regions). |
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Quantitative Research Approaches |
Descriptive or observational
case
case series
cross-sectional
cohort or prospective or longitudinal
case-control or retrospective
Experimental or longitudinal or repeated-measures
without a control group
time series
crossover
with a control group
Postal Surveys
Face to face interviews
Online Surveys
Panels/Structured Group Interviews
Questionnaire Design
Telephone Interviewing |
SAMPLE SIZE
How many subjects should you study?
Notice that for very large correlations you need a sample size of only 50 or so (This sample size would reduce the ability to say something about whether the variable in question is affecting the responses), but to nail a correlation as being small to very small, (i.e.to be able to say with some confidence that the variable in question is being influenced) you need at least 400 depending upon the size of your sample frame. |
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