The role and influence of meaning of function in design of artifacts

Transcription

1 The role and influence of meaning of function in design of artifacts - From the viewpoint of 'Prototype' Shengxi FAN*, Hisataka NOGUCHI ** * Chiba University C/o 1-33 Yayoi-Cho Inage-ku Chiba-shi Chiba-ken JAPAN, shengxi@dart1.ti.chiba-u.ac.jp **Japan Advanced Institute of Science and Technology C/o 1-1 Asahidai Tatsunokuchi-machi Ishikawa-ken JAPAN, hnoguchi@jaist.ac.jp Abstract: In the form making process of the design thinking, how functional meaning of the form was captured, and how it was expressed in the form are important problems. In this research, the thinking process of connecting function and form was analyzed in an experiment. In the experiment, the existing office type chairs, dining room type chairs, and object type chairs were disassembled into parts and put them random on the paper as two-dimensional drawings. The subjects were assigned to choose freely the given parts, and to design three different types of chairs. The results of the experiment were analyzed from the viewpoints of the kinds of selected parts, the relationship between the selected parts and change of selections in the thinking process. Then, the following things were clarified. 1. There was a form which symbolized each function of chair, and the parts tended to be selected predominantly as a typical part in such a meaning. 2. The form was structured as a functional unit through the relations between parts. 3. The transformation of form was performed with compatibility to keep functional rationality. 4. Comprehensive evaluation was related to the required function. 5. From the result of this experiment, it seemed in novice designer that, in the early stages of image generation, they tended to pick up parts which symbolized the function of each type of chair as the start point of design. Key words: Design thinking, Relation of parts and the whole, Meaning of function, prototype 1. Introduction This research aims to understand how meaning of function is captured by designer in the form-making process of the artifacts, and what kind of intellectual activity this process is, on the ground of method of cognitive science. This research focused on the evolving process of the form making from the viewpoint of 'Prototype'. The authors expect to have clues for understanding the structure of creative design thinking processes and for promoting the design creativity. 2. Method of research A design experiment was conducted to analyze the design thinking process. The subjects of the experiment were about 80 design students of Chiba University. The task they were assigned 1

2 was to design three different types of chairs by using a given set of parts of existing chairs. Then, the experimenters observed and analyzed their thinking processes based on the collected drawings and sketches. 2.1 Selecting the subjects of the experiment As the design thinking is depended on the personal knowledge, it is influenced by the experiences, educations and all other backgrounds of designer. To make that kind of influences minimum, the subjects were selected from the same class of design students. The another reason of selecting the subjects from design students was that the main interest of this research was in the fostering of design creativity, then the authors put more weight on the novices than the expert designers. 2.2 On the design assignment Design of the chair contains various design factors to be investigated. Especially, there are typical implications in the relations between a part and another part, a part and the whole, and the functions and forms. As chairs have long design history in human life, there are enormous existing instances of their design, and enormous people have prototypes of them, which may make it easy to develop the experiment. Moreover, some other experiments about chair design which relates to this research were already undertaken, which will make it easy to compare them with the results of this experiment on the same horizon, not only the analysis of this experiment deepened vertically. 2.3 Outline of the experiment. At first, seven existing chairs were chosen for making parts list from them, including each two typical chairs in office type, dining room type and object (artistic) type, and also one neutral type. Those selected chairs were broken down to parts in each, and the two dimensional line drawings of each part were listed with number-indices on the paper at random. The subjects were instructed to choose freely parts from the parts list and to design three different types of chairs in each as follows. (1) Office type chair (2) Dining room type chair (3) Object (Artistic) type chair The required conditions were put indices to each part and not to change the shape and proportion of each part. Any set of parts allowed to use except double use of the same set of parts in different type chairs. The given time was 1 hour and 40 minutes. Two experienced design educators evaluated the results of experiment in 5 grading evaluations of each evaluation items as follows. (1) Usability (2) Aesthetics of form making (3) Originality (4) Way of using parts (5) Generalized evaluation 2

3 3. Discussions on the results and analyses 3.1 On the prototype of the parts The number of parts given to the subjects was 54. The total numbers of 1245 parts chosen by each subject were collected and put in order by the types of chairs in relations with the parts and the corresponding chairs. As the result, it was found that there were obvious differences of distribution of selected parts in three types of chairs. The distribution was concentrated to the typical parts in each type, or parts of specific and characteristics shapes. For example, it was in such cases as the typical shape of the leg part of office chair, the straight lined structure of the dining room chair, and curved parts of the object type chairs. Those selections of concentrated parts showed the subject s interpretation of the basic concepts of three types of chairs in the intensive use of parts in each type. There were not chosen parts in each type other than the concentrated ones. For example, they were part No.43 and No.25 in the office chair, and part No.6 and No.54 in the dining room chair, and part No.6 in the object type chair. Selected frequency Fig.1 distribution of selected frequency of parts in three types of chairs It can be thought that the given parts indicated the relations between parts and the whole shapes in each existing chair, but the subjects thought them as the symbolic shapes of each category as a whole. In other words, the parts that concentrated in a certain type were indicated the characteristics of prototype of them. Then, it can be said that the characteristics of prototype in each type of chair existed as the characteristics of form of the parts. 3.2 On the power of meaning of prototype in relation of its function Generally saying, a conceptualized object is memorized and recollected as a whole image of the object. In the expression form of the concept, if it has no predicate part like as Chair, it implies generalized prototype of the object. In this experiment, the expression form of the concepts had predicate parts like as Office type, Dining 3

4 room type and so on. In this case, there was, at first, the generalized concept of Chair as the common part of the concept, and then the concepts of predicate parts Office type and Dining room type and so on were added on the common part. In other words, there were two layered concepts: basic concept layer of the chair and the concept layer which included the three predicated types of chairs upon it. The concentrated parts in each type chair indicated the typical parts of the each type. As the result, it was found that there was difference in the points and distributions of selected parts. In case of Office type, the selections were concentrated in several parts but in case of Dining room type, the selections were widely distributed. In case of Object type, a certain part was frequently selected but the other selections were most widely distributed. From the viewpoint of meaning strength of type expression, the strongest one was the Office type and the weakest one was the Object type. In relations of those results, the averaged number of selected parts in a designed chair was different: in Office type it was 6.4, in Dining room type it was 8.3 and in Object type it was 8.6. The number of selections in the most frequently selected part in each type was as follows: in Office type it was 13, in Dining room type it was 25 and in Office type it was 21. As mentioned above, it was found that the power of expression of prototype concerned with the strength of the meaning of function in each type. Fig. 2 The example of the use of the parts 3.3 On the process of the structuralizing by prototype In the original chairs, which included frequently selected parts in the experiment, there were parts that used as a pair and/or a set. In the parts list given at the start point of the assignment, the parts were arranged in the same layout as the original chairs in some case and not the same layout in other case. However, there was a tendency that the parts were separated from the set and used individually. The authors consequently understood that the subjects recognized the parts as the minimum unit. And at first a pair and/or a set of parts were treated separately, then in the next step, they were put in the new relations of a part and another part. Generally speaking, a simple geometrical form of the artifact contains the functional meaning respectively. The functional meaning corresponds to the basic concept of the artifact. From the viewpoint of morphology, some 4

5 parts in this experiment belong to the similar form. Though the basic functions of such parts correspond to the three types of chair theoretically, selected parts were concentrated to the certain type of chair, and they used as a part of different type chairs. Therefore, the result showed that the relations of part and part built the meaning of part in certain concept of chair. The mutual relationship of the actually selected parts was analyzed. From the result, a tendency was found that if certain parts were selected, then the parts which related to those parts were selected. Especially, in case of the chair, which had strong meaning of the function, there was remarkable tendency of structuralizing the relations of part and part around the characteristics of prototype. The combination of some selected parts could be seen in the selection of such related parts. Comparing the degrees of concentration of the parts selection in the three types of chairs, the Office type was in the highest rank, and the Object type was lowest one and no typical combinations. In case of the Dining room type, the range of combination was wide, and it seemed that it was not the relation of certain part but attention paid to the relevance of all selected parts. 3.4 On the change of the parts between the sketch and the final work This experiment went through two steps to grasp the thinking process of the subject's image formation and the conversion. The first half was took for sketch drawing and gathered all the sketches at the middle term of the task. After gathered sketches, copied them and back to the subjects, the second half was paid for making elaborate final works. Comparing each work in the final stage with the sketch of the middle term, the following things became clear. (1) The parts of high selection rate were used as a part of basic structure of chair and not changed their position through the task. (2) The parts changed during the task were mainly used as the components of aesthetic expression or simply as connections of part and part. (3) The change of images concerned with the strength in meanings of function. In case of strong meaning function, variation of form seemed to be restricted by the functional meaning and varied in the range of similar forms. (4) A change to the different form was done with the change in the related parts, and the development of the part was done with the parts. Such a change often related to the Aesthetics of form making. That results showed a tendency of the subjects thinking that the typical part was, at first, used as a base for thinking in the early stages of the image formation. The typical parts satisfied a fundamental design requirement through the selection of the parts, and it can be said that the operations for more effective change became possible. 3.5 Structuralizing the typical model by the typical parts For preparing the assignment, three types of existing chairs were chosen, in which two original forms were selected: one was the typical style and the other was a variation of it. The subjects seemed to have tendency that they concentrate to select the typical model in doing the assignment. Comparing with the number of selections of parts in typical models and the variations of them, there was apparently difference between them. In case of Office type, the number of the prepared parts chosen from typical model was 5 and the number chosen from variation was 13, and the number of subject s selections from them was 131 and 71. In case of Dining room type, 5

6 the numbers of the prepared parts were 10 and 8, and the numbers of subject s selections from them were 141 and 107. In case of Object type, the numbers of the prepared parts were 6 and 4, and the numbers of subject s selections from them were 74 and 38. With those ratios of selections from typical parts and the variations of them, it was found that there was a tendency of taking priority in selection of typical parts, and also a tendency of realizing the characteristics of whole shapes each prototype from typical parts of them. 3.6 On the evaluation of the subjects works As the result of comparison with the rank order of comprehensive evaluations on the subjects works and the rank order of selection ratios of the parts, there was a tendency that, in case of parts were selected from those of high ranked selection ratio, the results of the comprehensive evaluation of final works were also in high rank. In other words, it can be said that, in case of novices design thinking, to take a prototype as a clue made high possibility of success in the final design. In the evaluations in this experiment, at first, the evaluators graded in 5 for each evaluating item: Usability, Aesthetics of form-making, Originality, Way of using parts, and made generalized evaluation upon those results of grading. From the result of the Factor Analysis on the evaluations, it was found that the amounts of factor loading were different by the powers in functional meanings of each type. In case of Office type, the amount of factor loading was the highest in item Usability and the lowest in item Originality. In case of Dining room type, the amount of factor loading was also high in the item Usability but the highest item was Way of using parts. In case of Object type, the amount of factor loading was the highest in Originality but that in item Usability was lower than those in the other items. From the comparison of evaluations in all items in three types of chairs, it was found that the amount of factor loading of the item Aesthetics of form-making was in the same 3 rd ranking in all types of chairs, and the item Way of using parts was in the highest rank in Dining room type, but in 2 nd rank in other types. As mentioned above, in the selection ratio of parts, Fig.3 factor Loading of chairs of three types Office type was in the highest rank, but in the generalized evaluations, Dining room type was in the highest 6

7 rank and Object type was in the lowest rank. In other words, thinking characteristic of prototype was effective method for novices in all cases to bring out reasonable design, but it seemed to act oppressively for creative thinking. 3.7 On the categorization of the prototype As mentioned above, the result of the design of the artifacts can be thought that it concerns with the functional interpretation about the given concept. The development of the prototype can be done by the functional semantic interpretation in following three different categories. (1) A prototype upon the rigid selection of concentrating to the specific parts and/or related parts of them as seen in case of Office type. (2) A prototype upon the concentrated selection of some parts but various variations in the combination of them as seen in case of Object type. (3) A prototype upon the characteristic pattern in the combinations and structures of selected parts but not concentrated to specific parts as seen in case of Dining room type. Specific parts Office type chair Prototype of artifacts Specific parts And Related parts Dining room type chair Characteristic pattern Object type chair Fig. 4 The development of the prototype 4. Conclusion In generally, choosing an element at random is the method of avoiding preconceived idea. However, in the early stages of image generation, the subjects often selected at first a typical and functional part as a base. They seemed to use the typical parts as a clue to grasp a function of chair. In other words, the prototype of certain type of chair was embedded in the characteristics of the parts. But, the way of dealing with the characteristics of parts was different in interpretation of functional meanings of three types of chair. Therefore, the evaluation of creativity on the final work was varied by those differences. 7

8 5. Perspective The nature of design thinking process is the creation. The characteristic of the creative thinking is producing a fresh solution in deviated search from the stereotyped way in the process of thinking. How contribute the knowledge and experience of a prototype to creative design is the problem. As for them, to investigate the relation between the prototype and ability of thinking free from the established concept is important. From the viewpoint of education the research is also important on the possibility of promoting such ability. References 1. Finke RA, Ward TB, Smith M. Creative cognition, MIT Press, (1996). 2. Suzuki H. Ruiji to shikou (Similarity and thinking), Kyouritu syuppan, (2001). 3. Nagai Y, Noguchi H. Relations between Creativity and Student Design s Thinking types Observed in Sketch Drawings: On the Role Drawings in Creative Design Process (1), Bulletin of JSSD, 48(4), (2001). 4. Nagai Y, Noguchi H. Relations between Creativity and Abstraction Level of Thinking in Creative Design Process: On the Role of Drawings in Creative Design Process (2), Bulletin of JSSD, 48(4), (2001). 5. Purcell T, Gero J. Drawings and the design process, Design studies, 19(4), (1998). 6. Scrivener AR. Structure in idea sketching behaviour, Design studies, 19(4), (1998). 8