Ergonomia IJE&HF, 2005, Vol. 27, No. 1 , 53–60
Visual tests in design practice Jan Nuckowski Visual Communication Department, Faculty of Industrial Design, Krakow Academy of Fine Arts, Poland
Abstract Certain design problems make it necessary for visual communication designers to objectively verify their decisions. Visual tests constitute a reliable and well proven method of such verification. Methods in use comprise: test of maximum distance legibility, test of visual precise analysis, test of progressive vision, test of inclination, test of vibrating table, test with a movement simulator, and with a tachistoscope. Key words: rational design methods, visual tests, visual environment
Address for correspondence: Jan Nuckowski, Faculty of Industrial Design, Academy of Fine Arts, ul. Smoleńsk 9, 31-108, Krakow, Poland e-mail: zenuckow@cyf-kr.edu.pl
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54 1. Introduction The issues discussed in this paper constitute a significant part of the curriculum taught at the Visual Communication Department of the Industrial Design Faculty at Krakow Academy of Fine Arts. Since the beginnings of the Department (1972), its founders and staff have placed particular emphasis on searching for and applying rational methods of design. In research and teaching activities defined in this way, special attention is paid to visual tests which are a method of a multifaceted verification of visual communication elements. This is the topic to be outlined here. In professional practice, there are cases when the essence of the problems to be solved poses a challenge to visual communication designers, who, in order to face the challenge, have to pursue a special course of action (Otręba, Pluta, Nuckowski 1985a). These are design issues, the solution of which can influence safety, health, and even life of addressees/users of visual communication. It suffices to imagine poorly designed signs of technological installations in a factory which produces substances whose major components are chemicals hazardous to people. A deficient signalling system or inadequate signs used in various types of transportation can serve as another example of a case when the intuition of a designer does not suffice to arrive at an optimal solution. In such cases design methods which the Department endorses prove indispensable. These are procedures based on rational premises, which allow us to adapt the visual environment to our perceptive capabilities. It is imperative to have a stage of the verification of design decisions at which we exclude any possible mistakes to the extent moving beyond standard requirements. Another case which demands a special course of action is a situation when the design/project developed is addressed at a large number of recipients who are additionally under emotional pressure. A railway station, an airport, a hospital or any health
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Visual tests in design practice care unit can serve as an apt example. Misunderstandings and mistakes arising in such circumstances can prove both extremely costly and dramatic. Likewise, a special course of events can be required in a case in which the correctness and aptness of the project are decisive for the financial success or failure of a product which is being introduced on the market. Thus an unclear or inadequate packaging design can lead to a marketing fiasco. These are only a few examples of circumstances in which designers cannot rely solely on their intuition. Professional responsibility demands that all of their decisions should be verified on the basis of methods and procedures which enable us to test and check design concepts beyond all doubt. This paper aims to describe research techniques which facilitate the making of objective design decisions, which allow the adaptation of the physical properties of a visual communication message, or its component parts, to the requirements which the object in question has to meet. The research techniques presented here originated in varies disciplines. Most of them stem from the field of experimental and engineering psychology, some of them have been drawn up by institutions specializing in market research, others have been developed with the contribution of staff of our department. Simplifying for the purpose of clarity, we could divide the research techniques mentioned into the following: – psychological tests, – visual tests, also called physiological tests. The first category of tests focuses on examining people’s preferences, attitudes or opinions relating to the material which is being tested. The second category of research techniques is concerned with the sphere of relationships of the physical features of the objects examined. These features are treated as stimuli which trigger off specific physiological activities, i.e. visual perception. Visual tests enable the researchers not only to determine the presence or absence of a
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J. Nuckowski particular stimulus but also to measure its strength, intensity as well as other characteristics. In the first place, these tests serve the purpose of measuring the impact force of specific elements of visual communication. They do not inquire into the psyche of addressees. The subsequent part of the paper concentrates on this type of tests. The majority of tests presented here consist in the recreation, under laboratory circumstances, of situations or conditions which can take place in reality. It would be superfluous to explain in detail that visual messages are perceived from various distances and under changeable visibility conditions (fog, natural or artificial light) or that their location in relation to the observer is not always optimal. Each of such situations does not enhance the perception of visual communication, in fact, it becomes a moment of a critical verification. The authors of these visual messages should be aware that reality will be not always favourable for their visual communication messages. Therefore, it is essential to verify beforehand to what extent the messages designed would remain unaffected by such situations. The research techniques enable us to verify the compatibility of identification and legibility of complete messages, or their elements, with the legibility hierarchy which is assumed, designed and desired. Another aspect is relevant here. The majority of devices used for visual tests are equipped with appropriate scales. However, this does not mean that we arrive at absolute values as a result of our measurements. Scales are (or can be) a matter of convention and they can be adjusted to the character of the object tested. Therefore, visual tests are referred to as comparative tests since they consist in the comparison of two or more objects, or of specific features of the same object. 2. Methods in use In practice we encounter two types of testing devices called mechanical and projective respectively (Favre 1969; Otręba, Pluta,
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55 Nuckowski 1985b). The former makes it possible to display real objects, including three dimensional ones, whereas the latter makes use of different forms of two-dimensional presentation, e.g. by means of slides. In the tradition of the Department, the belief in the superiority of mechanical devices persists. The list of visual tests begins with a maximum distance legibility test. It is conducted by means of a distance-meter. The meter enables us to demonstrate the objects examined under conditions of changing distance between the object and the person participating in the test; in fact under a changeable viewing angle of an image (Fig. 1). It makes it possible to determine the maximum legibility distance of the visual message or its component parts. As a rule, the real distance between the object and the test participant is recorded. In this case, as in the following group of tests, to arrive at reliable results, five to seven persons should participate in the test.
Fig. 1. Test of maximum distance legibility (as percived by participant).
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Fig. 2. Test of visual precise analysis with use of visuoscope (as percived by participant).
Fig. 3. Test of progressive vision (as percived by participant).
The test of visual precise analysis enables us to display the objects examined under conditions of changeable image sharpness (Fig. 2). It is conducted by means of a visuoscope. The effect of image blurring or haze is achieved by inserting a focusing screen (ground glass) between the object examined and the test participant. A special scale registers the position of the screen, enabling us to read the object examined. After calculations, test results are given as percentages strength of visual influence of tested object.
The test of progressive vision consists in the presentation of objects examined under conditions of changeable light intensity (Fig. 3). It is conducted by means of a visuometer. The moment at which the test participant is able to read (identify) the message presented is recorded. Test results are calculated in lux.
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Fig. 4. Test of inclination (as percived by participant).
Fig. 5. Test with vibrating table (as percived by participant).
The test of inclination consists in the presentation of objects examined at an angle changing with relation to the axis of observation (Fig. 4). It is conducted by means of a visuo-angle-meter. The device registers the inclination angle of a (two-dimensional) object which makes it possible to read the message communicated.
The test of a vibrating table enables us to display the tested object under given vibration conditions. It is conducted by means of a visuo-vibrator. It is mainly applied to verify the legibility and reading speed of texts written in a given font (Fig. 5). The test is carried out at a programmed amplitude and frequency of vibration. Mainly the test is used to examine a readability of types. Time necessary for reading the text is recorded.
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Fig. 6. Test with movement simulator (as percived by participant).
Fig. 7. Test with tachistoscope (as percived by participant).
The test with a movement simulator. It is conducted with a device for simulating rectilinear movement in a given plane with the speed of the motion being controlled. The test makes it possible to observe types of apparent distortion of the object moving (Fig. 6). Observation results enable us to correct the objects tested in such a way that such deformations are prevented.
The test with a mechanical tachistoscope. It is a device which enables the display of the objects tested during an adjustable exposure time, from a very short one, under 1/1000 of a second, to a few seconds or more (Fig. 7). The tachistoscope is used to conduct a number of tests: visibility and legibility test, identification test and spontaneous draw attention test. An adequately conducted test provides a wealth of significant information about the product tested. The test enables us to determine the time needed to notice, recognize, read and finally identify the visual message or its elements. Depending on the type of a test, five to seven or even over ten persons should participate in it.
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J. Nuckowski To conduct a test correctly, the same conditions as for the first participants should be recreated for the following participants. In most cases five to seven participants suffice. Only in a few cases shall the number of participants increase to over ten. A special recruitment of persons willing to participate in the test is not essential, however, there might be cases when specific limitations and criteria are introduced. Each test begins with the simulation of conditions least favourable for perception and then, gradually, the conditions are improved. The choice of test depends on the features of the object to be tested and on a set of information which a research program has to supply. Generally, single tests are conducted and only in special cases, when the object is of particular significance, is the number of tests increased. Visual tests provide a maximum objectivization of all forms of visual information. Their aim is to adapt physical properties of a visual communication message, or its components, to the requirements that have to be fulfilled by a given object, be it a warning sign, a signalling device, a control desk or an item of verbal information. These are only a few examples of numerous cases in which objects can or even should undergo a verification procedure of visual tests. Moreover, it is relevant to note that visual tests can be applied to new solutions not only in their final stage of completion but also in intermediary stages when the solutions are still “work in progress.” Likewise, already functioning objects should be verified when questions arise as to whether they adequately fulfil their tasks. Some of the described methods can be applied in the initial stage of problem analysis, thus looking ahead to and specifying the design problem 3. Example of testing procedure Finally, I would like to give an example of how visual tests are put to practice. It is a part of a complex study conducted in the Department of Visual Communication as an answer to the request put forward by a cos-
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Fig. 8. Examples of cosmetics packaging used in “spontaneous draw attention test”.
metics manufacturer. The study was carried out by the team of the Department staff including Jan Nuckowski, Ryszard Otręba and Władysław Pluta. An integral part of the study was a set of visual tests, including a spontaneous draw attention test. Such a test is conducted by means of a tachistoscope. In this case three cosmetics packaging boxes were tested, two of which were already in use and the third one which was newly designed (Fig. 8). The boxes were displayed in pairs in the following sequences: 1-ab, 2-ac, 3-ba, 4-bc, 5-ca, 6-cb. In initial experiments, before the beginning of the testing session, one common time period for all exposures was set. The test participants saw the tested products six times and each time they were asked the same question, “Please point to the packaging which has attracted your attention.” The pairs of the packaging boxes presented were rotated and thus the first person saw the sequences in the order 1, 2, 3 ...6, the second person – 2, 3, 4 ... 1, the third person – 3, 4, 5 ... 2 and so on. 50 persons, 25 men and 25 women, participated in the test, The recruitment of test participants according to sex was to determine whether there exist relevant differences between male and female preferences. The reasons for particular answers were not investigated. The analysis of test results, however, allowed us
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Visual tests in design practice to provide justified suggestions as to which preferences led respondents to give particular answers. Test results were presented in a table. They recorded the number of indications per packaging box. The test showed that the new packaging box received the majority of indications (Fig. 9). The methods and devices presented here are applied in research, teaching and design work conducted by the staff of the Visual Communication Department of the Industrial Design Faculty at Krakow Academy of Fine Arts. Such an approach to new tasks and challenges contributes to our deep conviction that we co-participate in the creation of optimal and ergonomically correct conditions for the development and functioning of people in their visual environment.
Fig. 9. Results of “draw attention test” – percentages of indications by male and female subjects.
References Favre JP, 1969, Color sells your Package. ABC Verlag, Zurich. Otręba R, Pluta W, Nuckowski J, 1985a, Techniki i urządzenia stosowane w wybranych badaniach wizualnych. Problemy obrazowania informacji pomiarowej. (Techniques and equipments used in some visual tests) Prace Naukowe Instytutu Metrologii Elektrycznej Politechniki Wrocławskiej, Wrocław. Otręba R, Pluta W, Nuckowski J, 1985b, Application of video technology and devices to selected visual tests. Design for information. ICOGRAPHIC, vol II/6, London.
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