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CHAPTER 3 The Aims and Objectives

Following the Introduction, you should look for a clear statement of the purposes of the current work. This statement can come in two forms: the aims of the study and the objectives.

 Aims are general statements about purpose. For example, the authors might wish to examine the attitudes of hospital nurses to colleagues with mental health problems.

 Objectives are specific questions, suggested by previous research or theory. For example, ‘Does taking the oral contraceptive pill increase the risk of stroke among women of childbearing age?' One particular sort of objective is to test an hypothesis.

Because the terminology of hypothesis testing is so widely used, we will start there.

HYPOTHESES

Often, studies will ask more than one question, so they will have several hypotheses. In these circumstances, you should look for a main hypothesis (Figures 3.1 and 3.2) and the other questions will form subsidiary or secondary hypotheses.

Figure 3.1 Statement of a study's main hypothesis.

Source: From Thompson et al. (2000), © 2000 Elsevier.

Figure 3.2 A study with two hypotheses.

Source: From Tebartz van Elst et al. (2000), © 2000 Oxford University Press.

There are important reasons why a study should have only one main question:

 If a study tests many hypotheses, then just by chance it is likely to produce positive results for some of them. (See Chapter 31 on hypothesis testing and the possibility of false‐positive results from multiple testing.)

 We can trust a negative result only if we know that a study was large enough; otherwise, there is a possibility of false‐negative results. Many researchers therefore make an estimate of sample size to help them decide how big to make their study so that they can avoid this sort of error (see Chapter 13). To do that calculation they need to know what the main outcome of interest is, and the main outcome will be chosen to test the main hypothesis.

There used to be a conventional way of stating a study's hypothesis, which involved the use of a null hypothesis and the description of a study set up to disprove or refute an hypothesis. Although this approach is still sometimes taught, you will almost never come across examples in papers. The null hypothesis was a way of stating a question in the form ‘situation A is no different from situation B'. It arose because certain statistical tests operate by testing whether an assumption of similarity is likely to be true.

The need to refute rather than prove an hypothesis is similarly based on a technical point – about the nature of scientific evidence. In fact, nearly everybody now states their hypotheses in a straightforward way, as an interesting question framed in everyday language. The English doesn't have to be difficult to follow for the science to be right!

OBJECTIVES THAT ARE NOT HYPOTHESIS TESTING

Not all questions are framed as hypotheses, even in quantitative research. For example, in a study examining the rate of antibiotic resistance among post‐operative wound infections the authors might have no definite rate in mind.

And many studies are not designed to test hypotheses at all – for example some are designed to generate new ideas and questions for future research. This is especially true of qualitative research, which is generally speaking more exploratory – asking a question when we might not know what answers to expect and where we don't want to measure something but to understand its nature. In other words, although qualitative studies do not usually test hypotheses, they are still designed to answer a question. For example, in the study illustrated in Figure 3.3 the researchers were asking the question: ‘What do people with progressive life‐limiting illness want to know about their condition – for example about its consequences and its treatment?'

Figure 3.3 The (structured) Abstract of a qualitative study, starting with an implicitly stated question.

Source: From Selman et al. (2009), © 2009 BMJ Publishing Group Ltd.

In other cases it can be harder to see exactly what the question is. For example, the study illustrated in Figure 3.4 talks about capturing experiences and views of service users and carers, which doesn't sound like an objective, but perhaps a general aim. However, if you read the rest of the paragraph in this Abstract it becomes clearer that there is a more specific question, if quite a complex one: ‘Is the idea of a patient career useful in helping us to organize our thoughts about how service users describe their experiences of mental health services?'

Figure 3.4 The aim of the qualitative study.

Source: From Jones et al. (2009), © 2009 Elsevier.

A particular type of objective is to develop new hypotheses for testing in future research, so‐called hypothesis‐generating. Sometimes hypotheses are generated by subgroup analysis and post‐hoc examinations of the data produced by quantitative research (Figure 3.5). Hypothesis generation of this sort should be regarded as unreliable, but, for all that, it may produce interesting ideas. Be careful to look out for it, because some authors present these as established results rather than ideas for future work.

Figure 3.5 New subgroup analysis in report of an RCT.

Source: Reproduced from O'Connor et al. (2017). Licensed under CC BY 4.0.

STUDIES WITH UNCLEAR OBJECTIVES

If you cannot find a mention of the study's objectives expressed as aims or specific questions, you may yet be able to find them expressed in less clear‐cut ways. Examples include ‘exploring associations' or (worse) ‘examining issues'. You will need to be particularly careful about studies with such vague objectives: because they are not asking a specific question, it is not easy to tell whether the results are meaningful. Quantitative studies with unclear prior questions can produce results that are due to chance – especially as a result of post‐hoc or multiple testing. Qualitative studies, when they start without a clear question, do not tend to produce misleading results as much as uninteresting ones.

As a final note, we want to say something about why we think it's worth so much effort to clarify the exact aims and objectives of a study. To do so, we will outline a small thought experiment. Suppose you are working as a general medical practitioner and a mother brings a child to you, saying she is worried that he is not growing and is shorter than all his peers. The appropriate initial response would be a piece of quantitative research to answer the question: ‘Is this boy short for his age?' You would measure his height, checking it against suitable norms.

Suppose now you see another child whose mother is worried that he seems unhappy and withdrawn, but she does not understand why that should be. You are likely to want to undertake some qualitative research – asking him in a relaxed and unstructured but purposeful way whether he does indeed feel unhappy, and if so why? In other words you match the design of your inquiry to the question you are asking. Now, it would be possible to have a chat with the first boy and ask him his experiences of growing up and being (perhaps) on the short side, and you could give the second child an age‐appropriate standardized mood rating scale. You will have produced results but not answers because in neither case would your method of inquiry be appropriate to your (or the mother's) specific prior questions.

These examples introduce another question often asked of researchers: where do the aims and objectives come from? Of course, the answer is often that they come from gaps in our knowledge or theories. However, another interesting possibility is that they come from, or at least are influenced by, the views and experiences of people with personal experience of the condition being researched. This is one of the main functions of what is often called Public and Patient Involvement (PPI for short) in research – making sure that the objectives of research and the way those objectives are met will be of relevance to the ultimate consumers of research findings.

We hope that when you read research reports you will therefore have in mind your own queries: are the aims and objectives clear, and is the researchers' chosen method the best one to meet their aims and objectives?