Scientific Method and Design (Engineering,...)

This part assumes you have read the first two sections — What is a problem? The Process of Design — in An Introduction to Design.

Design and Science
What is the connection between design and science? Broadly defined, a designer is anyone who tries to improve a product, strategy, or theory. Since the overall goal of science is the designing of improved theories about nature, science is just a special type of design, devoted to solving one kind of problem. But when we are studying the methods used by problem solvers over a wide range of areas, it is useful to distinguish between two types of objectives: the designing of products or strategies (which I'll call design) and the designing of theories (which is science).

As described above (in The Process of Design), goals and predictions and observations can be compared in three ways: two are the main strategies in design, and one is the main strategy in science,

In science our overall long-term objective is to search for the truth, to develop theories that are accurate representations of reality. During this search our most useful thinking tool is a reality check that compares observations with predictions.
In conventional design the main objective is to develop an improved product or strategy, and our most useful tools are quality checks that compare goals with observations, or goals with predictions. Although in design it may be useful to get feedback about theories by comparing predictions and observations, this is not the central focus of action, as it is in science.

Despite these differences in objectives and methods, there are many similarities. In both activities, there is goal-directed "design action" with a creative generation and critical evaluation of ideas, plus experimentation (mental and physical) to produce the predictions and observations that (as you can see in the diagram) are a central part of the thinking process. { When scientists design theories, what are the goals? }

2 and 3. In these two new sections we'll begin with summaries of process (in scientific method and design method) before moving into comparisons of science and design.

2A. The Process of Science
In scientific logic, as in daily life, you use reality checks to decide whether "the way you think the world is" corresponds to "the way the way the world really is." ... A physical experiment allows observations of what nature actually does, and a mental experiment lets us make predictions about what nature will do. In a reality check, scientists compare OBSERVATIONS with THEORY-based PREDICTIONS. If a theory fails in a reality check because its predictions do not match observations, scientists can reject the theory. ... Most philosophers think that, according to formal logic, we cannot prove a theory is either true or false, but we can develop a rationally justified confidence in our conclusions. .....
The diagram below has three main elements: OBSERVATIONS, PREDICTIONS, and THEORY. If you study the diagram and the summary above, it should make sense. Notice the arrows pointing away from theory (because a theory is used for making predictions, as explained above) and toward theory (because observations are used to generate a theory, as explained below).

2B. The Process of Design
The first step in solving a problem is recognizing that it exists. You recognize a problem when you understand the way a situation is now, and you can imagine a future in which things have changed and improved. Or maybe you can imagine a future in which things have changed but have not improved, and you want to avoid these changes. Either way, if you want to take advantage of your opportunity to make a difference, you will generate and evaluate ideas-and-actions that help you make progress toward solving the problem.
Imagine that you are trying to design a product, and your overall objective is "an improved refrigerator."
You define your quality-GOALS by defining the desirable properties of a satisfactory product. In this case, what kind of "improvements in the refrigerator" do you want? Your goals are based on your knowledge of what is, and your imagination about what could be.
Usually, the search for a solution begins by remembering old products, by searching your own memory and our collective memory (in books, websites,... and in other people) for existing products. For each old product, you collect OBSERVATIONS of the product's properties, and ask "How closely do these known properties match my goals for the properties of a satisfactory product?" In this question, you are comparing observations with goals in a quality-check that lets you determine how well a product meets your quality-goals, which are your criteria for defining quality.
You can widen your range of options by imagining new products. Usually, a new product is invented when, guided by goals, you begin with an old product and make changes. Based on what you know about the old product and new changes, you can do mental experiments to predict the properties of a new product. Or you can predict the properties of an old product in a new situation. In either case, you use your PREDICTIONS by asking "How closely do the predicted properties match my quality-goals?" In this quality-check, you are comparing predictions with goals.
You can also gain knowledge by testing a product (old or new) in a physical experiment that lets you make OBSERVATIONS about properties. Then you can ask, "How closely do the known properties match my quality-goals?" In this quality-check, you are comparing observations with goals.
Design Decisions: You use quality checks (by comparing quality-goals with observed properties or predicted properties) to evaluate each potential product, old or new. Eventually, you may find a product that satisfactorily achieves your goals, and you consider the problem solved. Or you continue searching, or abandon the search.

The same process of action-and-logic is used for designing a product or strategy. But the process is different for designing a theory in science.

3. Comparing Design and Science
If we define design as the designing of products or strategies, and science as the designing of theories, how are design and science related? What are the similarities and differences, in process and purpose? The actions-and-logic used in design and science are summarized in this diagram:

DESIGN Method: During the process of design, you set quality-GOALS for desired properties, use physical experiments to make OBSERVATIONS, and use mental experiments to make PREDICTIONS, so you can do QUALITY CHECKS either by comparing observations (of known properties) with goals (for desired properties) or by comparing predictions (of expected properties) with goals (for desired properties). If you want to understand design method better, study the diagram and this brief summary to get an overview of "the big picture" and then re-read the previous section about The Logic of Design.
SCIENTIFIC Method: During the process of science, as explained earlier and shown in the diagram, OBSERVATIONS (from physical experiments) are used to imaginatively generate a THEORY, which can be used with if-then logic (in a mental experiment) to make PREDICTIONS, so you can do a REALITY CHECK by comparing observations with predictions, to test whether "the way you think it is" (assuming the theory is true) corresponds to "the way it really is."
Comparing Process: The methods used in science and design are related, yet different. The three elements of thinking — goals, observations, and predictions — can be compared in three ways. Two comparisons (of observations with goals, and predictions with goals) are used in design for quality checks. One comparison (of observations with predictions) is used in science for a reality check.
Comparing Purpose: In design, the main objective is to develop a product or strategy, to invent or improve something that is humanly constructed. In science, the main objective is to develop theories, to understand nature that (I think) is divinely constructed.
Comparing Process-and-Purpose: In design, we use quality checks to decide whether a particular product (or strategy) satisfactorily achieves our quality-goals for the product (or strategy). In science, we use reality checks to test whether a theory corresponds with reality, whether it is true. The process is different because the purpose is different.
Comparing Overlaps: Often, the results of science can be applied in the designing of products or strategies, but this is not the main objective of science. During design it may be useful to improve a theory that is being used while developing a product or strategy, but theory development (which is the main objective in science) is not the main objective in design.
Comparing Cousins: Although it can be interesting to compare science with a wide range of design fields, it seems most immediately useful to compare science with its closest cousin in design, which is engineering. Comparing objectives, we see that science tries to understand nature, while engineering tries to improve technology. Notice the two differences: understanding versus improvement, and nature versus technology. But there are also similarities, interactions, and overlaps. The understanding gained by science is often applied in technology, and science often uses technology, especially for making observations but also in other ways. Sometimes in science or engineering — for example, when we try to understand the chemistry and physics of combustion in automobile engines — we study the behavior of nature in the context of technology. And because the definitions we're using distinguish between science and design on the basis of purpose-and-process (objectives-and-methods), not careers, a scientist sometimes does engineering, and an engineer sometimes does science.