Quantitative research in almost all cases requires a large-scale study.

Large-scale studies

There are several key concepts that we need to consider when looking at samples, and these are:

In order to determine your sample, you have to take all the above into account, in terms of the make-up of your sample. This of course depends upon what you are wishing to study.

For example, if you are looking at the efficiency of a particular nursing care on reducing the anxiety of elderly men in hospital for a prostatectomy, then your sample will obviously be made up of :

Now you can decide who will make up your sample, so write this into your own research proposal.

Sampling criteria

Within that group above, you will need to determine your inclusion and exclusion criteria. 

In the example above, you may wish to include only those who have a wife/partner, etc., and exclude those who live on their own (possibly because your intervention may well require the co-operation and involvement of a close relative to support the intervention.

You may also wish to exclude those men who are not fully aware and articulate enough to take part in the intervention - or those who cannot speak English well, etc.

Whatever inclusion and exclusion criteria you use, you must, as always be able to provide a rationale for both the sample and the inclusion/exclusion criteria.

So now it is time to formulate the criteria for your own research (either actual or virtual) and write it into your own research proposal.

Method of recruitment

How are you going to recruit your sample?

First of all you need to make sure that your sample is the correct type to answer your hypothesis or research question, and that you have used the correct type of sample. From chapter 7 of the accompanying book, you will note that there are  2 major classes of samples:

Probability samples, which usually include random samples, can be divided into:

Non-probability samples include:

So, you have decided what type of sample you want/need to answer your research question or prove/disprove your hypothesis - how do you recruit the participants?

Well, there are various ways, but all of them need a 'gatekeeper'. Gatekeepers are people who have access to your population/sample and can help you also to access them. Examples of gatekeepers are:

There are many more potential gatekeepers, and it is important that you work through them initially as they can smooth your way in terms of contacting your potential participants, and also give a degree of authority and support for you and your research study.

Either you or your gatekeeper could initially contact the potential participants to find out if they are interested in taking part in the research. Often, because of data protection and patient confidentiality issues, it is often advisable to allow the gatekeepers to make the initial contact, and you can do the follow up if the potential participants intimate that they are interested in taking part.

At this stage there are several documents that you need to prepare and have ready for the potential participants, including:

All the above needs to be written in your research proposal so that the people who will grant you permission to go forward with the research know exactly how you will recruit the participants and the safeguards that you have in place to prevent undue pressure being put on the potential participants.

Potential Problems

In this section you have to assess whether or not there could be any problems arising with the sample you are going to use for your research. For example, is there any inherent bias or perhaps a lack of representativeness within your possible sample.

In other words, you have to reassure the people from whom you are hoping to get permission to do your research that you have thought about this and identified any such problems, and also you have identified how you can deal with (or at least minimise) these problems. On the other hand, there may not be any, but it is still a good idea to say this in your proposal, so that you have shown that you have thought about it.

Health and Comfort of the Subjects

Within this section, as with the section above on potential problems, you have to convince that you have considered this very important aspect of the due care and attention that you need to pay to the needs of your sample.

This can include the risk of potential physical and/or psychological harm that may arise within your sample as a result of your research. Again, you may be certain that there is no risk of any harm arising from your research, but you need to mention this, and also generally look at how you intend to ensure the comfort of your sample.

Remember that for the duration of your research (and to some degree after the research is completed), the people who make up your sample are your responsibility in terms of anything that may occur as a result of your research study.

Your proposal

Having considered all the above, now you can start to think about your potential research in terms of these issues. Although it may seem complicated from all that has been written above, in actual fact it is quite simple - you just need to think about your research hypothesis or question and that will guide you in the determination of your sample.

So now make some notes under all the headings above, and then before writing your completed section on your sample(s), look at the example from a quantitative research proposal that we keep returning to so that you can see how it can be written.



Think about the research that you are proposing to undertake. Have you thought through your sample make-up, number and inclusion/exclusion criteria? To help you, click on the icon below to look at the research question and hypothesis in the example of a qualitative research proposal that we are using as a guide.




Now that you have planned the strategy for the determination and recruitment of a sample for your own research (either actual or virtual), you can write it into your own research proposal.