Test Method

The subjective garment evaluation study is based on the approach developed by Norman Hollies at Gillette Institute. This wear trial approach gathers human responses to test items while participants follow a schedule of specific activities. A customized test protocol is developed to include periods of physical activity alternating with periods of rest in both moderate and mildly warm climatic conditions. Prior to donning the test ensemble and beginning a test session, there is a preconditioning period where evaluators, upon arrival, sit quietly for 15 minutes to come to a relaxed state. An important part of the activity routine is the exercise period that produces a sweat-wetted-skin condition.

Outlined in the table below is a representative test protocol of our standard wear trial procedure.

*Designed to produce sweat: treadmill walking/ running, group aerobics with a video

The test garments are randomly assigned to evaluators so that different types are worn in each test session. This practice assures that more independent ratings are obtained. Additionally, evaluators are instructed not to discuss the test garments or their ratings. A customized evaluation form is designed to obtain ratings of comfort and sensory tactile properties for each of the periods outlined in the protocol. Customarily, the first three items on the evaluation form require evaluators to rate overall comfort, warm-cool feeling, and softness of the material. Normally, rating values of these items range from 1-7 as they appear on the evaluation form with 7 representing the most comfortable, coolest, and softest garment.
Descriptor terms are selected to be representative of the fabric properties that are most relevant for the test garment application. The descriptors are stated negatively because individuals are better able to discern degrees of tactile unpleasantness than degrees of tactile pleasantness. Values of 1-5 are assigned in these ratings with 1 = "totally" and 5 = "no sensation" (do not sense any negative quality). Higher values denote a more desirable quality.

The table below contains a list of suggested descriptor terms with an associated physical property of the garment fabric.

Evaluators

Typically 30 - 40 participants are used in a study depending on whether the study is for males or females or a combination of both. Evaluators are obtained from the North Carolina State University, T-PACC subject pool which includes persons, primarily students, who through a screening process are determined to be healthy nonsmoking individuals between 18 and 35 years of age. Considered first are experienced evaluators who have participated in previous studies. All evaluators receive an initial orientation regarding the requirements of being a wear trial participant.