Members of the sample are drawn at random from the population of interest.
The spread of values between the minimum and maximum values in a distribution of values.
In measurement, the extent to which a measure produces the same results each time the same measure is taken (in the same way). Reliability is important in deciding whether the results of a piece of research are accurate.
Conducting a piece of research more than once to see if the same results emerge. Replicability is important in deciding whether the results of a piece of research are accurate.
A sample that accurately reflects the population from which it is drawn.
Is a process of investigating, exploring, studying, examining or looking into something in a systematic way.
The way the research will be undertaken, including population to be studied, the type of sampling, the research methods that will be used and the way the results will be analysed. Research design should reflect the type of data and information required from the study.
Knowledge acquired through a systematic and transparent process of enquiry.
Procedures for conducting research studies and gathering and interpreting data. Some examples of research methods are questionnaires, interviews or focus groups.
A method of accumulating knowledge that involves several distinct steps. Identifying a problem, defining that problem in terms of a question that is capable of study, developing a plan to answer the questions, gathering data according to prescribed practices, and drawing conclusions from the data.
An adjective applied to a statistic or a statistical procedure which implies that the value of the statistic or the outcome of the procedure will be relatively unaffected by the presence of a small number of unusual or incorrect data values.