Tahira Reid

Impact of Product Design Representation on Customer Judgment

When researchers ask customers to judge product form during the design process, they often manipulate simplified product representations, such as silhouettes and sketches, to gather information on which designs customers prefer. Using simplified forms, as opposed to detailed realistic models, make the analysis of gathered information tractable and also allows the researcher to guide customer focus. The theory of constructed preferences from psychology suggests that the product form presented will influence customer judgments. This paper presents a study in which subjects were shown computer sketches, front/side view silhouettes, simplified renderings, and realistic renderings to test the extent to which a variety of judgments including opinions, objective evaluations, and inferences are affected by form presentation. Results show a variety of phenomena including preference inconsistencies and ordering effects that differed across type of judgment. For example, while inferences were consistent across form, opinions were not. An eye tracker identified differences in viewing strategies while making decisions. Associated data, such as fixation times and fixation counts, provide additional insight into findings.

Perceptual Attributes in Product Design: Fuel Economy and Silhouette-Based Perceived Environmental Friendliness Tradeoffs in Automotive Vehicle Design

The quest for improved fuel efficiency and environmental friendliness is transforming automotive vehicle design. In addition to new energy sources and management, new powertrain technologies offer increased flexibility in the spatial arrangement (packaging) and exterior shape (styling) of a vehicle. Design choices in packaging and styling are closely linked to consumer preferences, particularly those that influence consumers’ decisions about the objective qualities of a product (i.e., perceptual attributes). The ability to include perceptual attributes into a design optimization study is a valuable extension of the more traditional engineering approach that looks at only functional attributes. Previous work has studied the quantification of perceived environmental friendliness (PEF) in vehicle silhouette design. In this paper, empirically validated PEF silhouette attributes are included as constraints in a vehicle optimization model that maximizes fuel economy. Results indicate that there is a tradeoff between PEF preferences and the attainable fuel economy for a given vehicle, where increasing vehicle length leads to increasing PEF and decreasing fuel economy.

Enhancing Visual Thinking in a Toy Design Course Using Freehand Sketching

ABSTRACT Engineering graduates in advancing economies are not onlyexpected to have engineering knowledge, but also use them increative and innovative ways. The importance of visual thinkinghas been critical for creativity and innovation in design. How-ever, today’s engineering students are proficient in detailed de-sign tools but lacking in conceptual design and ideation, and en-gineering curricula needs to develop a more effective frameworkfor teaching visual thinking. In this paper, we report our effortsto embed principles of design thinking and visual thinking prac-tices, like McKim’s “seeing, imagining and drawing” cycle [1].We use a toy design course in mechanical engineering for ourpilot study as a scaffold for introducing these principles in anengaging, creative, and fun environment. We introduced free-hand sketching as a tool for visual thinking during the design andcommunication of concepts. We also report the impact of thesechanges through information gleaned from student feedback sur-veys and analysis of design notebooks. We use our findings topropose ways to provide the students with a set of balanced tech-niques that help them in visual thinking, communication, and de-sign. An improved implementation of this experience is discussedand future work is proposed to overcome barriers to thinking andcommunication.

A Methodology for Quantifying the Perceived Environmental Friendliness of Vehicle Silhouettes in Engineering Design

Methods from psychology and engineering are used to quantify subjective, or perceptual, design attributes of artifacts. A modeling framework of perceptual attributes suitable for inclusion in design optimization is presented. The framework includes stimuli development based on design of experiments, survey design, and statistical analysis of data. The proposed modeling method is demonstrated on a subjective attribute we call ‘perceived environmental friendliness’ using vehicle silhouettes as a case study.Copyright

Comparing Functional Analysis Methods for Product Dissection Tasks

The purpose of this study is to begin to explore which function identification methods work best for specific design tasks. We use a 3-level within-subject study (n=78) to compare three strategies for identifying functions: energy-flow, top-down, and enumeration. These are tested in a product dissection task with student engineers who have minimal prior experience. Participants were asked to dissect a hair dryer, power drill, and toy dart gun and generate function trees to describe how these work. The function trees were evaluated with several metrics including the total number of functions generated, the number of syntactical errors, and the number of unique (relevant and non-redundant) functions. We found no statistical, practical, or qualitative difference between the trees produced for each method. We also found some generalized findings through surveys that the most difficult aspects of using functional decomposition include identifying functions, choosing function verbs, and drawing the diagram. Together, this may also mean that for novice engineers, simpler methods, such as enumeration, should be taught prior to more complicated methods so students can grasp core concepts such as identifying functions and structuring function diagrams.

EVALUATING THE BOTTOM-UP METHOD FOR FUNCTIONAL DECOMPOSITION IN PRODUCT DISSECTION TASKS

The purpose of this study is to continue to explore which function identification methods work best for specific design tasks. Prior literature describes the top-down and bottom-up approaches as equivalent methods for functional decomposition. Building on our prior work, this study tests the bottom-up method against the top-down and enumeration methods. We used a 3factor within-subject study (n=136). While most of our diagramoriented metrics were not statistically different, we found statistical support that: 1.) students reported that the dissection activity was more useful when using bottom-up, and 2.) that student engineers committed many more syntax errors when using the bottom-up method (by listing parts instead of functions). We believe that both these results are due to the increased focus on individual parts. We do not know if an increased attention to the parts would increase novelty or fixation, and recommend future studies to find out.

Impact of Product Design Representation on Customer Judgment With Associated Eye Gaze Patterns

Researchers often use simplified product form representations, such as silhouettes, sketches, and other two-dimensional representations of products, to examine customer preferences. While these simplified representations make the analysis procedure tractable, for example linking certain design manipulations to certain preferences, the reality is that people evaluate more sophisticated product representations during purchase decisions. This paper presents the results of a study where two groups of people were shown either computer sketches and front/side view (FSV) silhouettes or simplified renderings and realistic renderings of cars and coffee carafes. Human judgments measured included opinions, objective evaluations, and inferences. Results show a variety of phenomena including preference inconsistences and ordering effects. Data collected from an eye-tracker help to elucidate these findings.© 2012 ASME

Understanding the Utilization of Information Stimuli in Design Decision Making Using Eye Gaze Data

Research on decision making in engineering design has focused primarily on how to make decisions using normative models given certain information. However, there exists a research gap on how diverse information stimuli are combined by designers in decision making. In this paper, we address the following question: how do designers weigh different information stimuli to make decisions in engineering design contexts? The answer to this question can provide insights on diverse cognitive models for decision making used by different individuals. We investigate the information gathering behavior of individuals using eye gaze data from a simulated engineering design task. The task involves optimizing an unknown function using an interface which provides two types of information stimuli, including a graph and a list area. These correspond to the graphical stimulus and numerical stimulus, respectively. The study was carried out using a set of student subjects. The results suggest that individuals weigh different forms of information stimuli differently. It is observed that graphical information stimulus assists the participants in optimizing the function with a higher accuracy. This study contributes to our understanding of how diverse information stimuli are utilized by design engineers to make decisions. The improved understanding of cognitive decision making models would also aid in improved design of decision support tools.Copyright

Reducing Sketch Inhibition During Concept Generation: Psychophysiological Evidence of the Effect of Interventions

This research investigated the effect of warm-up activities on cognitive states during concept generation. Psychophysiological tools including electroencephalography (EEG) and galvanic skin response (GSR) were used along with self-report measures (NASA TLX). Participants were divided into 3 test conditions: 1) no warm-up activity; 2) simple warm-up activities; 3) sketchinhibition reducing activities. All participants did the same short design task. Results show that those who did a warm-up prior to ideation had a decrease in stress, especially for those who were not personally familiar with the design problem. The art activities especially improved engagement for younger participants. We also saw that females who used the art-based activities reported lower mental workload during ideation and greater pride in their sketches. However, the warm-ups did not produce any difference in the number of ideas or other metrics of performance. These preliminary results indicate that warm-up activities, especially the art-based ones, help reduce inhibition by calming the cognitive state.

Informing Early Design via Crowd-Based Co-Creation

Customer inputs in the early stages of design can potentially lead to completely new outlooks in concept generation. We propose crowd-based co-creation as a means to this end. Our main idea is to think of the customer as a source of initial design concepts rather than a means for obtaining preferences towards designer-generated concepts. For analyzing a large collection of customer-created prototypes, we develop a framework that focuses on generating hypotheses related to customer perception of design attributes. We demonstrate our approach through a web interface to gather design requirements for a computer mouse, a bicycle seat, a pen holder, and a cola bottle. This interface was used in a crowdsourcing study with 253 users who represented potential end users for these products. Results from this study show that web-based co-creation allows designers to capture a variety of form and function-related design requirements from user-created virtual prototypes. We also found that such studies can be instrumental in identifying innovative product concepts, and gaining insights about how user perception correlates with product form. Therefore, we make the case that customer creation through distributed co-creation platforms can reinforce concept exploration in future early design processes.Copyright