How to Create Theory of Design

  1. Format of Presentation of Design Theory
  2. Preparing Design Theory
En Español  In
Finnish   Contents

In the figure below, design and production are shown as streams of knowledge which originate from descriptive research, are refined into design theory and continue finally as a product development project.

Research of design

The diagram indicates also the division of research activities around products into different groups:

The diagram above does not imply that design were impossible without the help of a well sorted design theory. On the contrary, there is always the traditional method of design without any explicit theories. Moreover, it is to be noted that even the most complete theory cannot foresee every possible problem of design. The designer must be free to work even in such a way that a researcher would find irrational; and it should be left to the designer to decide if he wants to use the theoretical tools provided by the researcher.

Format of Presentation of Design Theory

Design theory is a collective denomination for all the permanent knowledge that is intended to assist the design of various new products. This information has mostly been gathered by a great number of research projects. Corresponding to the usual approaches of research, the information is essentially of two types:

  1. Nomothetic knowledge, i.e. general rules that have been gathered from several different products. To this group belong:
  2. Idiographic knowledge which actually concerns only individual products but is nevertheless suitable to be generalized to other products as well:

All the above types of study are discussed more in detail in Format of Presentation of Design Theory on the page Arteology and Theory of Design.

Preparing Design Theory

Developing design theoryDesign theory is based on research, but in this case the research aims not only at describing the object nor explaining why and how it has attained its present state. These descriptive insights may be useful as a basis for design theory, but more essential for the design of new objects is to evaluate whether the present state of things is good or bad, and to specify in which respect we should ameliorate the object of study (or other, similar objects). This latter type of research is called normative. Let us take a closer look at its logic.

As already the diagram above indicated, normative research is done in two contexts: either on a general level in the purpose of producing universally applicable theory, or on the level of a specified practical problem or project. The latter case shall be discussed not here but on separate www-pages titled Developing an Activity and Developing a Product.

The procedure and methods of normative study differ from Descriptive research mainly because the practical goal is present throughout the process. Another usual difference is the participation of the users of the results, which means that many procedures will have to be repeated until the result becomes acceptable for all. Moreover it is usual that the operations will more or less merge to each other, in other words the process does not divide into so clear phases than is common in descriptive study.

It might seem that logically the most explicit procedure for amelioration would be to proceed in stages: first to describe the present state of things, then to discuss its strong and weak points, then agree on the points which shall be corrected, and finally plan the method of correction. Such a procedure (the so called "rational planning" process) is not very common in the practical study of products. The process seldom starts from impartial description because normally a recognized need of improvement is the very starting point of a normative project and it tends to permeate all its stages.

Anyway, at least in principle it is possible to discern a few subsequent logical phases in the process of preparing design theory:

  1. The initial decision about launching the project, made by an organization capable of financing the study and of implementing its proposals. The decision reflects a preliminary opinion on the need and importance of development and its estimated scope which can, of course, be corrected later.
  2. Planning the scope of development: the approximate extent of practical changes or of new products; the population of people who are expected to benefit from these, and the general principle of sampling: who are the people whose opinions shall steer the development? See below.
  3. Evaluative description of the present state of things where the existing problems and inconveniences are defined and assessed. Potential methods for gathering data are explained under the titles Studying Static Objects and Observation, and for collecting people's opinions about them, Interrogating Methods. Suitable analysis methods are Normative Case Study , Normative Comparison , Normative Classification , Normative Study of Variables and Normative History.
    The present state is preferably described as a model; it will help in the subsequent operations. Examples of normative models can be found in Methods Engineering , Action Research and Design Driver.
  4. Defining the target state tentatively. If you made a model of the initial state of the object it will give a good basis for these plans, see below.
  5. Planning the procedure of development tentatively. Outlining preliminary proposals of how the renovation can be accomplished.
  6. Testing phase: putting the proposals to practice tentatively in small scale (for example, with the methods of Evaluating a Design Proposal). Gathering and analysing feedback and setting up the final proposal. Do not forget possible side effects to outsiders. It may be necessary to gather the wishes and views of various stakeholders in the development project and try finding a consensus.
  7. Decision-making and practical realization will not be discussed here because the researcher seldom can partake in them. The task of the researcher is to formulate his recommendations so that they suit the prevailing administrative procedures and the degree of participation, if applicable. Sometimes it can be useful also to forecast the future development in the case that no intervention is done; on this basis it will be possible to consider how rewarding the project will be and is it worthwhile to continue it.

Whose point of view is used? Normative research aims at improvements, which means that it includes evaluation of the present state of things and also of the direction of future development. By definition, evaluation is only possible from somebody's point of view. It thus at once becomes necessary to define whose point of view is used in the evaluation.

One obvious group of potential evaluators are the future users or employers of the required improvement, for example the expected customers or users of a product that shall be developed, or those people who are now suffering from problems that could be alleviated with the help of research and development. The difficulty is that the consequences from normative research and development are often visible first in future years, which restricts the possibilities of finding competent evaluators. Often the best available substitute for the population of future beneficiaries of development is simply the current (adult) population of the country, region or city where the research is done. Sometimes you can add the demarcation of socio-economic class: school children, students, young people, those living alone, young couples etc. up to pensioners. Language, sex and prosperity are also potential partitions.

Beside the beneficiaries of development who often voluntarily participate in the development project there can be people who inadvertently have to endure some side effects of the project, for example the pollution from a new product or its fabrication. It will seldom be possible to enumerate these "stakeholders" in a development project or to have direct contact with them. In principle, these people are often included in the populations that have been defined on the basis of a geographical area (as mentioned above) but in practice the people that are going to receive the side effects seldom are aware of the fact in advance. Instead, you might consider inviting representatives from environmental or consumer associations to participate in evaluation.

A third important population are those people whose participation will be needed in the development phase. In product development, these include people in the manufacturing and marketing divisions of the company, if they are known. However, when developing theory of design these people are seldom known. Instead, you might wish to invite specialists of the pertinent new technology to participate in the project, but the difficulty is that the specialists of a given technology almost never belong to a definite population that you could enumerate and select a proper sample of it. Examples of potential sources of specialists are given under the title Populations of evaluators.

The general alternatives and available procedures for demarcating a population of study are discussed elsewhere. If the target population turns out to be very large, it may be advisable to pick out a sample of it. All these operations have to be done carefully, otherwise you risk getting bias or tendency in your results. A tendency is in principle the same thing as a systematic error, which means that afterwards it will be almost impossible to remove it from the data.

Compressing the opinions. No matter how meticulously you define the people whose evaluations shall dictate the direction of practical operations, it sometimes turns out that these evaluations are more or less in conflict. Evidently each subjective evaluation is based on individual values and personal beliefs which in turn depend on the social environment and on the person's various earlier experiences. In descriptive sciences this variation is often welcome and interesting and the normal practice is then to collect the variable opinions of people and find out which groups of people agree with each opinion, do these groups correspond with existing social classes and which are the social and psychological reasons for supporting each opinion.

As a contrast, in normative study which is expected to point out the optimal or the most acceptable strategy to be used for subsequent practical operations a large variation in opinions is a nuisance. Of course, there are many questions on which nearly all people agree, for example the functionality, safety and ecology of products and procedures, and disputes are not likely on these questions. However, in other questions the preferences may differ and it becomes difficult to select the goal for practical action.

The normal initial situation in normative study is that many alternative practical strategies are conceivable, and often each alternative has supporters among people, but circumstances allow only one strategy for realization. The researcher needs in this situation methods for compressing the distinct opinions into one collective resultant which then determines the choice of practical actions. In the following there are some approaches which you can use to attain such a consolidation. (Their methods are explained on the page about Normative Research.)

Note that the very concept of compressing people's opinions is somewhat crude. A personal opinion is something which a researcher cannot always profoundly understand, let alone competently modify. That is why the output from any of the above methods for compressing should be used with caution. It could be advisable to test the proposed compromise with a renewed questionnaire or a few thematic interviews with persons from either the original sample or from the target population.

Transition from descriptive theory to normative one. The methods of normative research are mostly similar to the usual methods of descriptive gathering of empirical data, their analysis and evaluation. The main difference is that one or more variables or attributes of the object of study have to be recorded not only objectively but also as evaluated by people, and the associations between objective and subjective values of attributes have to be analyzed. Usually no very sophisticated analysis methods are necessary.

If there is earlier disinterested theory on the object that you wish to develop, it is usually advisable to use it as a basis for your normative work. The logical transformation from description to norm starts typically from an invariance of change found by descriptive research. The form of such an invariance is usually one of the following:

A disinterested invariance of change having been found, it is usually simple to rewrite it into the normative format of an instruction of design (or of other activity):

"If you want A, and believe the situation is B, you should do X"

In a development project the target is usually not only achieving a certain result, but also doing it without unnecessary effort and cost. In other words, the practical process should be optimized. The possible benefits should be compared to the likely costs without forgetting eventual harmful consequences, either.

How to present design theory. An optimal settlement for all parties having been found, the last task left for the researcher-editor is to give it a serviceable written form. The presentation style of design theory should be flexible and suited to all the phases of design. During the first stages of design, fairly rough tools will be needed, and for the finishing touches, more detailed ones.

A simplified, approximated technical norm can sometimes be more useful in practice and thus finally in fact more effective than a more exact but more impractical version of the same norm. On the other hand, too much simplification can lead to a loss in the desired effect: often it would be too simple to assume e.g. that the user of the product is an "average" person because, to be exact, no user ever is.

When a standard or other instruction of design is being set up, the binding power of each instruction and of each subdivision should be clearly stated. E.g. the following categories are quite different as to their binding capacity:

It would, however, be clumsy to complement each sentence with a phrase which defines the binding power of this sentence in the text. Instead, you can use typographical symbols, such as font, color and placement of text. For example, in the National Building Code of Finland all the pages have one wide and one narrow column, and the text is printed in a number of different fonts. The meaning of these is as follows:

In the instructions, it may be well grounded to indicate their period of validity, or, alternatively, there should be a procedure to cancel obsolete instructions.

It goes without saying that it must be indicated who has issued the instruction, because this indicates the binding power of the instruction.

En Español  In Finnish   Contents

August 3, 2007.
Comments to the author:

Original location: http://www2.uiah.fi/projects/metodi