Research Clarification
3.4 Clarifying Criteria, Main Questions and Hypotheses
initial model of the existing situation, i.e., the unsatisfactory situation with the support.
In summary, irrespective of the original research goal, initial models of the existing situation and of the desired situation including the preliminary success factors are necessary to clarify understanding and expectations, and select the type of research.
possible within the duration of the research project, ‘product quality’ is chosen as the preliminary Measurable Success Factor, and ‘high product quality’ as preliminary Measurable Success Criterion. This criterion needs further operationalisation in order to be able to be used, i.e., the terms ‘high’ and ‘product quality’ have to be defined in such a way that this can be assessed within the project. For further details on formulating operational definitions, see Section 4.5.2.
Figure 3.10 shows the Initial Reference Model based on the literature sources of the example and the alternative example. The model includes the preliminary Key Factor and the preliminary Success and Measurable Success Factors. Note that this model is simplified. In a research project, a Reference Model is likely to be more complex and to have more than one Success and Measurable Success Criterion.
Figure 3.10 Initial Reference Model including preliminary criteria
Based on the Initial Reference Model and the expectations, the Initial Impact Model is updated, and the preliminary Key Factor and preliminary Success and Measurable Success Criteria added, see Figure 3.11.
As the research project progresses, Measurable Success Criteria become more precisely defined and may change. Success Criteria usually do not change. For instance, the support developed may introduce new influencing factors, which may require new Measurable Success Criteria, or the development of a support may prove to be more time consuming than expected. As a consequence less time is available for evaluation, and fewer or even different criteria may have to be chosen.
When alternative Measurable Success Criteria are chosen, care should be taken that the corresponding Factors too are as closely linked as possible to the Success Factors.
use of DfR methods preliminary
Success Factor
product reliability customer
satisfaction market share
+ + +
[1]+
price
_ + _ 0 [2]
other factors other factors
[A]
[1]
[1] +
_
quality of product
__
[1]
maintenance cost
_ + +
warranty cost
+ ++
[4]
[3,4]
[3]
+
operating cost
+ + _
[3]
[5]
preliminary Measurable Success Factor
+ 0 project time left% of to improve
_
product- specificity of DfR methods
_ 0
+ [E]
[A]
preliminary Key Factor quality of
production
use of DfR methods preliminary
Success Factor
product reliability customer
satisfaction market share
+ + +
[1]+
price
_ + _ 0 [2]
other factors other factors
[A]
[1]
[1] +
_
quality of product
__
[1]
maintenance cost
_ + +
warranty cost
+ ++
[4]
[3,4]
[3]
+
operating cost
+ + _
[3]
[5]
preliminary Measurable Success Factor
+ 0 project time left% of to improve
_
product- specificity of DfR methods
_ 0
+ [E]
[A]
preliminary Key Factor quality of
production
Figure 3.11 Initial Impact Model with preliminary Criteria
3.4.2 Research Questions and Hypotheses
We often observe that PhD students present their work describing what they are doing or planning to do, but fail to state the research questions and hypotheses behind their work. When research questions are formulated, they are often very vague, too encompassing to be answered within one PhD project, and concerned only with the support to be developed (e.g., ‘how to assess reliability’). To undertake research, the formulation of the main research questions and hypotheses early in the project is essential. During the course of the project, these will be refined and elaborated on to focus the various stages of the research process.
A research question is a question for which no answer exists yet. Research questions can be formulated in various ways, such as: What are the characteristics of a successful product? How often do designers..? How do designers do..? What are the ways in which..? How long does it take to..? When does…? Why is…? The type of question determines the research approach and, in particular, the methods that can be used. The selection of the most suitable methods is discussed in Section 4.6. In our example, some of the research questions would be: What causes the lack of product reliability? How does product reliability influence maintenance cost?
How can we assess reliability in an early stage?
An hypothesis is a tentative answer to a research question in the form of a relationship between two or more concepts, or in our case, between two or more influencing factors, including the Success Factors. That is, an hypothesis is a claim
use of DfR methods preliminary
Success Factor
product reliability customer
satisfaction market share
+ + +
[2]+
other factors other factors
[1]
+ _
quality of product
++
maintenance cost
_ +
_
warranty cost _ __
_ _ _
preliminary Measurable Succsss Factor
+ + project time left% of to improve
+
preliminary Key Factor
assess reliability in early design
stages
_
+
price
operating cost
quality of production
use of DfR methods preliminary
Success Factor
product reliability customer
satisfaction market share
+ + +
[2]+
other factors other factors
[1]
+ _
quality of product
++
maintenance cost
_ +
_
warranty cost _ __
_ _ _
preliminary Measurable Succsss Factor
+ + project time left% of to improve
+
preliminary Key Factor
assess reliability in early design
stages
_
+
price
operating cost
quality of production
or statement about a characteristic of a situation, or a proposed explanation for a phenomenon. Hypotheses are tested as to whether they can be accepted or have to be rejected given the available evidence. In our example, an hypothesis behind the expected effect of the support is that ‘If a lack of reliability is detected in an early design stage, sufficient project time is left to improve the product’. Every link can be formulated as an hypothesis, e.g., ‘An increase in product reliability will increase the quality of the product’ (see Figure 3.11). Because this link is crucial in the Reference Model and based upon a reference from a different area of application, it would be important to investigate this hypothesis.
The main research questions and hypotheses can be derived from the research goal, the Initial Reference and Impact Models, and the related discussions. A detailed discussion on how to formulate research questions and hypotheses, so that they can be answered and verified, can be found in Section 4.5.2.