Vision and touch
Humans will develop different perceptions when touching the fabrics without seeing them compared to touching and viewing the fabrics.
To examine the relationship between vision and touch, two experiments were conducted within different contexts. The third experiment allowed participants to physically see and touch the sweaters while the fourth experiment invited participants to touch the sweaters while blindfolded. A paired t-test was conducted on the results of experiment 3 and 4. Table 1 shows no significant relationship between the results of experiments 3 and 4 (p-value > 0.05). Regardless of the type of knitted fabric, there was no statistically significant difference.
As a result, the data appears to reject the premise of the first hypothesis. Despite being blindfolded, participants were able to perceive the tactile properties of knitwear as well as they did without a blindfold. These findings demonstrate the strong influencing power of physical touch as people evaluate fabrics. Regardless of vision, physical touch is the more important sense when evaluating tactile properties.
Tactile properties of knitwear cannot be accurately conveyed through digital photos and videos.
This hypothesis was examined in experiments one and three using a paired t-test (Table 2). In the third experiment, people can physically see and touch the sweaters freely. Conversely, the first experiment only offered visuals of the six sweaters for participants to evaluate on screen. As a result, statistically significant differences were identified in certain components of sample evaluations between both experiments: sample four in the evaluation of heaviness (p-value = 0.04) and sample four in the thickness evaluation (p-value = 0.03).
Further differences were identified in the evaluation of stretchiness and flexibility, which participants stated was the most difficult component to evaluate on screen. Among the six samples, samples two and five showed differences. Participants pinpointed sample two (p-value = 0.02), which is thin but dense, and sample five (p-value = 0.04), which is thick but loose, as the hardest samples to evaluate the actual feeling of the fabric. The same samples [sample two (p-value = 0), sample five (p-value = 0.02)] were the hardest samples to evaluate on the basis of stretchiness.
The results demonstrate that it is difficult to perceive the tactile properties of the fabric solely by reviewing them on screen, even if videos are also provided. Stretchiness and flexibility in particular are the hardest properties to discern through a computer screen without physical touch.
A limited haptic experience of the material’s surface will not increase the accuracy of the tactile evaluation.
In addition to the experiments used to evaluate the second hypothesis, another experiment was conducted to specifically determine if a surface haptic experience could reduce the uncertainty of perceiving fabric properties. Surface haptic devices are designed to help people evaluate the texture of fabric through a pad when they cannot physically touch the fabric. The second and third experiments were analyzed in a paired t-test (Table 2), and these results were compared to the results of the first experiment, which were obtained when testing the second hypothesis, to identify if a surface haptic experience can increase the accuracy of tactile perception.
The results indicated no significant differences between (p-value > 0.05) the evaluations of stretchiness and flexibility. The data show that a surface haptic experience can reduce the uncertainty in evaluating samples two and five, which were considered by participants as the most difficult fabrics to evaluate using only visual materials. However, significant differences were discovered in the heaviness of sample three (p-value = 0.01), and the thickness of samples two (p-value = 0.02) and five (p-value = 0.03). This result indicates that the surface haptic experience is helpful in evaluating the stretchiness and flexibility of fabrics, but it cannot assist people in evaluating the heaviness and thickness of fabrics.
Figures 3 and 4 display a comparison of the average scores on the evaluation of stretchiness and flexibility, respectively. The third experiment provides a reference value that shows the results from an actual haptic experience while also allowing participants to physically see and touch the sweaters. The figures confirm the difficulty in discerning the stretchiness and flexibility of the product using only visual materials on screen (experiment one). However, a surface haptic experience (experiment 2) can considerably increase the accuracy.
Qualitative data analysis
All participants were interviewed following the experiments. Interviews were recorded and transcribed verbatim. Iterative-inductive analysis of qualitative data involving open coding was conducted. First, the data were categories by the type of experiments. Examples of categories included tactile cues on screen (E1), tactile cues on a swatch with visual materials (E2), tactile cues in real touch experience of sweater (E3), and tactile cues when blindfolded (E4). In each category, data were divided in to 4 subtopics: thickness, heaviness, stretchiness, and flexibility. During the process of open coding, data were broken down in to pieces to discover relations, similarities, and differences. Then, axial coding was conducted to recombine the subcategories by its characteristics. Finally, selective coding was adopted to develop core categories and new concepts. To ensure the trustworthiness of this study, the authors and an expert who had PhD degree in clothing and textiles were involved in the entire process of coding. These three coders checked the application of coding to the data. To confirm the consistency between coders, the inter-rater reliability was calculated and the result was 97.2%. Microsoft Word and Excel were used to code and determine inter-rater reliability without the use of programmed coding software.
Findings from the interviews
All participants were interviewed following the experiments. In experiment 3 and 4, intuitive responses were found from participants. As participants were able to actually see and touch the sweater by hand in Experiment 3, there was no interesting finding from the interview. The power of touch was confirmed from the comparison of experiment 3 and 4. Although participants were blindfolded in experiment 4, participants felt very comfortable evaluating the tactile properties. It indicated that people could perceive tactile properties well when they were allowed to touch the product freely despite the absence of vision. Some interesting insights were determined from the interviews of participants in the first and second experiments where they were evaluating fabrics using visual materials on screen. Those insights are described below.
Evaluation of thickness and heaviness
The thickness of the yarn influenced the participants’ perception of heaviness. If the yarn appeared to be thick visually, participants assumed that it would be heavy. Conversely, if the yarn appeared to be thin, participants assumed it would be a light fabric.
I think heaviness and thickness go together. Since it is hard to feel the weight through the screen, naturally I look for thickness to evaluate heaviness (Participant 2).
Participants also agreed that the density of fabric affects perception if the thickness appears similar. The density of fabric is related to the opacity of sweaters displayed on the body. If the fabric is loose enough to determine the shape of the body through the clothes, it is considered thin and light. On the other hand, if the fabric has a high density that cannot be seen through, it is considered to be thick and heavy.
In addition to the density, the number of folds is also an important factor for the evaluation of heaviness and thickness. Participants commonly identified the shape, width, and number of folds as clues. As the model rotates in the video, the movement and folding of the fabric help in evaluating heaviness and thickness. If the fabric does not fold, it is considered heavy and thick. In contrast, if multiple folds are created as the model rotates, the fabric is considered light and thin. Large, wide folds are associated with thick and heavy fabric, whereas small, narrow folds are associated with thin and light fabric.
Participants also examined the edge of the clothing to determine thickness. If the edge of the sweater appears to be flat against the skin, the fabric is more likely to be considered thin.
Evaluation of stretchiness
The evaluation of stretchiness on screen depends on the density of the knitted fabric. If the fabric appears to be tightly knitted so you can’t see through it, it looks stiffer. Regardless of the same yarn being utilized, knitwear appears more stretchy when it is loose-knitted and you can see through it.
A participant highlighted that fabric memory can affect the perception of the sweater, especially when they have to evaluate through visual materials on screen.
…If I have experienced similar types of knitwear and I have a memory that it stretched well, it affects the evaluation. The previous memory makes me think that it can be stretched well, even if it does not look so (Participant 6).
Participants expressed difficulty in feeling stretchiness through visual materials in a non-touch environment. They just assumed that the sweater was stretchy if the fabric looks light and thin on screen. On the other hand, it was considered as non-stretch if it looks heavy and thick,
Folds were an important factor in the determination of heaviness and thickness as well. Participants agreed that if there are many narrow folds diagonally, the fabric would have more stretch. On the other hand, when there are no folds, the fabric is considered to be stiff.
Evaluation of flexibility
Participants commonly agreed that flexibility was related to the thickness and density of the fabric. If the fabric appeared to be thin, loose-knitted, and transparent, it is considered to be flexible. On the other hand, if the yarn is thick and the density of the fabric is high, it is considered to be stiff.
…Flexibility was the hardest part to evaluate. I think photos can’t deliver the feeling. Only videos can give a hint. How the clothes on the body behaves is the clue (Participant 4).
The thickness around the edge of the clothing as well as the shape, width, and number of folds are clues to help evaluate fabric flexibility. If there are many folds, the fabric is likely to be more flexible. Additionally, when the fabric appears light and thin, it is considered to be soft and flexible.