Introduction                                            Summary
                                                    Procedure                                                Conclusions / Recommendations
                                                    Participants                                              Appendix

Introduction

    The recent increase in popularity of health and fitness products has produced countless devices to measure one's body composition.  One such device is the Omron Body Fat Analyzer Model HBF-301, which is a hand-held device that reports body fat percentage in just seven seconds.  The purpose of this report is to describe the results of a usability test of this device on individuals aged 27 to 80 years old and to discuss individual reactions to the body fat analyzer.  This report follows the further research recommendations made by Amy Pierce, a student who performed a similar test in Fall 2002. (http://www.bsu.edu/web/ampierce/usability.htm).  

For more information about the Omron Body Fat Analyzer Model HBF-301, please visit the following web sites:
http://www.omronhealthcare.com/wellness/bodyfatanalyzers/hbf_301pp.html
http://www.omronhealthcare.com/PDF/Product_Sheets/Wellness/HBF_301.pdf


Procedure

    Five individuals were recruited and tested at the home of one of the participants.  Each participant was read the Usability Script.   Since the purpose of this test was not to discuss body composition, the participants were ensured that they were not required to discuss their results with the tester or other participants.  Once the participants' questions had been answered, the tester asked three Pre-test Questions to determine individual characteristics and familiarity with the product. (Pre-test question #2 was used to ensure the accuracy of the body fat measurement and was not used in the usability test analysis).


The participants were asked to perform five tasks using the Omron Body Fat Analyzer Model HBF-301.  Tasks 3 through 5 were read verbatim from the instruction manual.  

Task #1:  Turn the device on.
Task #2:  Program the device.  (This involved four steps):
                              a.  Input your height.
                              b.  Input your weight.
                              c.  Set your age.
                              d.  Confirm gender.
Task #3:  Wrap your middle finger around the electrode grooves.  With your thumb and index finger, securely grasp the upper portion of the electrode.  Wrap your ring and little fingers around the lower portion of the electrode.  Now press your palms firmly against the electrodes.
Task #4:  Stand with your feet shoulder width apart and arms straight out in front of you at a 90 degree angle.  
Task #5:  Start the device.

Following the test, the participants were asked four Post-test Questions.


Participants

The chart below indicates the participants' responses to the pre-test questions.  Since the device uses a small electric current to measure body fat, anyone with a pacemaker, who was pregnant, or had other concerns about using the device was not allowed to participate.

Participant	Gender	Age	Exercised vigorously, showered, drank alcohol, or drank water in the past hour?	Ever used body fat analyzer before?	If yes to analyzer, which make and model?
1	M	27	No	Yes	Omron HBF-301
2	M	57	No	No	N/A
3	F	80	No	No	N/A
4	M	60	No	Yes	Unsure
5	F	58	No	No	N/A

Summary

    The participants thought aloud as they used the device and were willing to discuss their reactions to the product.  Participant #2 stated that he rarely read instructions for technical devices, so he was comfortable attempting to use the product for the first time without having read the manual.  Two of the participants had some confusion when asked to turn the machine on because they were unsure of whether to press the "start" button or the "on/off" button.  There was also some confusion on the first step by one of the participants because nothing indicated that he needed to press "set" to begin programming the device.  One participant got stuck when asked to set his age because it was unclear to him that the number that was flashing was age.  Another participant was discussing his thoughts so openly with the observer that the machine "timed out" and turned off automatically during his testing and he had to start over and reprogram the device.  Two of the elderly participants had difficulty grasping the device correctly due to arthritis in their hands.  Despite these difficulties, most found the analyzer to be fairly easy to use.  One participant even offered to purchase the analyzer from the tester!


Conclusions and Recommendations

    When asked to rate the user friendliness of the body fat analyzer on a scale from 1 to 5 with 5 being the easiest, the average response was 3.6.  Answers were varied when asked about specific areas of difficulty while using the analyzer.  One participant stated that he had to guess what to do since he did not have instructions.  Another participant discussed his annoyance with having to start over when the machine automatically turned off during his testing.  The 80-year-old female participant thought that the device registered too high a percentage of fat and had difficulty grasping the device due to arthritis in her hands. The fourth participant stated that it was unrealistic to expect people to know their height to the nearest 1/4" and weight to the 1/2 lb.  The fifth participant also had difficulty grasping the device correctly due to arthritis in her hands.

    When asked how easy it was to read the display with 5 being the easiest, the average response was 4.6.  One participant commented that it was very easy, another commented that the bottom figures should be as large as the top figures, and a third participant simply stated that the type could be a little larger. Overall, the participants were satisfied with the display unit.

    Several recommendations were made by the participants for the Omron body fat analyzer.  Participants 1 and 3 suggested that the start button be placed where it can easily be reached while grasping the device. It was also suggested that the device include BMI (body mass index) measurement as well.  Participant 2 suggested that instructions be printed on the bottom of the device and that the display flash to warn that it is about to automatically turn off.  Two of the participants suggested that the gripping be made more user-friendly for those with arthritic hands.  Another participant suggested changing the increments for height and weight to the nearest whole inch and pound.  

    With the rapidly aging baby boomer population in America, creators of devices such as this will have to consider the ability of elderly people to use their products.  Even the youngest of the baby boomers may have some arthritis that will have to be taken into consideration when using certain products.  This is something that may have already been taken into consideration since there are now bathroom scales that measure both weight and body fat percentage without the user having to grasp anything.  Omron has also created updated models that may be more user-friendly for elderly people.  Information on one such  model can be found at the following web site: http://www.omronhealthcare.com/wellness/bodyfatanalyzers/hbf_306pp.html.  
   
    Following this usability test, several recommendations for this model of the body fat analyzer come to mind.  First, the start button and power button should switch places so that the start button is within comfortable reach of the thumb while grasping the device.   It would also help if the directions for using the device were on the display.  For example, "Press 'set' to begin" could be on the display after the power is turned on.  It would also be helpful for the display to list the recommended range of body fat percentage so that the user is better able to interpret their own results.  Another suggestion would be for the device to calculate Body Mass Index (BMI) as well.  BMI is calculated by dividing weight by height.  Since the device needs this information anyway, it should be simple to program it to use that information to calculate BMI.  This would be valuable information for the user because it is possible for a person to have a healthy body fat percentage, but a high BMI, which would indicate an increased risk for disease.  The reverse is also possible, so both numbers would be useful.
   
    Future researchers may test the effectiveness of this device in motivating people to develop a more healthy body composition.  Further, the study could reveal what people learn from the device and what, if any, lifestyle changes the users actually make after learning their body composition.  

Appendix