In a previous blog, I wrote about how best to draw a sample. In the blog, I briefly described the difference between a select and a random sample. There is a substantial difference between the two.

In a random sample, everyone in the focus population has an equal chance of being in the sample. This sample is also called a probability sample or random selection. There are several methods for doing a random sample:

• Single random sampling: the lottery method, you randomly select a number of people. This can be done manually or by computer.
• Systematic random sampling: you choose a random number and then go through your list in steps, for example, 20-120-220 etc.
• The cluster or bunch sampling: the list is divided into several clusters. And then, a group is chosen at random.
• The quota sampling: In advance, it is known how many respondents are needed; when that number is reached, the data collection stops.

In a select sample, not everyone has a chance to be in the sample group. The results apply only to the group being studied. There are a number of selective sampling options:

• Snowball sampling: At first, one person is talked to; this person is asked if they know anyone who would also be interesting to talk to. And so on until the sample is large enough. When doing this, make sure you approach people with different perspectives; otherwise, your sample is flawed. Use this method when conducting interviews.
• The convenience sample: the researcher approaches people from his circle or the circle of colleagues until the sample is large enough. Of course, this sampling method is not fully representative because the respondents are chosen on insignificant factors (would know).
• Stratified sample: you divide the population into different groups. A representative number of respondents are chosen from each group.
• The two or multi-stage sampling: a sample is first drawn from several main categories. After this, a representative number of respondents are chosen from the selected main categories. For example, first a number of cities are determined, and from these cities, a neighborhood and then a street per neighborhood. This method is not a good reflection of the population.

From the conversations I have with various people who do research stems some confusion about the term research methods. There are theories on which you can conduct a research study, and you have multiple ways of collecting data.

In my blogs, I regularly talk about research methods, referring to the various ways of collecting data.

Once you have clarity about your research questions, you examine what information you can collect and how. There are many different methods to do this. You have qualitative research methods and quantitative research methods. Qualitative research methods are not about facts and figures but rather about how and why. Quantitative research methods are more about facts and figures that can be compared. Also, check out my blog about the difference between qualitative and quantitative research methods.

There are all sorts of research methods. My overview blog of different research methods lists different ways. Also, be creative with the ways you collect data. Look beyond the standard practices of research and make interesting combinations.

Once you have chosen a research method, thorough preparation is essential. Look at what you need per method and take the time to set up your measuring instrument properly. Discuss it with colleagues and test the measuring instrument before using it.