Sampling in mixed research builds on your knowledge of sampling in quantitative and qualitative research. Typically, the researcher will select the quantitative sample using one of the quantitative sampling techniques and the qualitative sample using one of the qualitative sampling techniques.
Sampling in mixed research can be classified into “mixed sampling designs.”
Mixed sampling designs are classified according to two major criteria:
The first criterion is called time orientation. Time orientation is provided by the answer to this question: “Do the quantitative and qualitative phases occur concurrently or sequentially?”
In a concurrent time orientation, the data are collected for the quantitative and qualitative phases of the study at approximately the same time. Both sets of data are interpreted during data analysis and interpretation.
In a sequential time orientation, the data obtained in stages; the data from the first stage are used to shape selection of data in the second stage.
The second criterion is called sample relationship. Sample relationship is determined by answering this question: “Is the relationship between the quantitative and qualitative samples identical, parallel, nested, or multilevel?”
In an identical sample relation, the same people participate in the quantitative and qualitative phases of your study.
In a parallel sample relation, separate quantitative and qualitative samples are drawn from the same population and they participate in your study.
In a nested sample relation, the participants selected for one phase are a subset of the participants selected for the other phase.
In a multilevel sample relation, the quantitative and qualitative samples are selected from different levels of a population.
You can combine these two criteria just discussed—time orientation (which has two types) and sample relationship (which has four types)—to form eight mixed sampling designs:
(1) identical concurrent
(2) identical sequential
(3) parallel concurrent
(4) parallel sequential
(5) nested concurrent
(6) nested sequential
(7) multilevel concurrent
(8) multilevel sequential.
For reference, these eight sampling designs are described (but you do not need to memorize them!):