Usability testing is conducted for products to determine two items; utility and usability (Nelson, 2000). Nelson (2000) stated that utility is determined by how the product functions (can it do what it is intended to do), while usability "is the question of how well users can used that function" (Nelson 2000). To determine how well people can use a particular function of a products requires the usability test to include the following parts.
1. Focusing the test on the users (participants in the actual test)
2. Having the participants use the product in the test
3. Having participants accomplish a task
4. Having participants decide if and when a product is easy to use ( Dumas & Redish, 1999)
For this particular usability test the Strait-Line Laser Tape was chosen to evaluate. This usability test was designed to produce data that will determine both the effectiveness and efficiency (critical elements in a usability test) of the Laser Tape (Jordan, Thomas, Weerdmesster, & Clelland, 1996). The Strait-Line Laser Tape is a tool that is used to make volume, area calculations along with addition of various measurements possible with out the use of a tape measure. The Laser Tape consist of a laser, ultrasonic sensor, screen, and interface (these components are outlined in product description). The usability test preformed for this product is an attempt to uncover any issues that a potential consumer might encounter while using the Laser Tape. One of the most important aspects of usability testing is putting the product in the hands of test subjects (Usability Testing) which is the ultimate goal of this particular usability test. Each of the exercises in this usability test is designed to collect data on how subjects interact with the product (Laser Tape).
The methodology used to complete the usability test for the Strait Line laser tape consisted of first obtaining volunteers to participate in this test. Participants were selected by randomly asking people who were passing by the testing facility if they would like to take part in a usability test. The only requirement is that the people who did volunteered had to be a legal adult (18 years or older). People were asked until a small group of participants were formed (seven volunteers), which was considered a fair number for this particular usability test (U.S. Department of Health & Human Services, 2009).
Before beginning the actual usability test, participants were given a brief questionnaire (Pre-Test Questionnaire)to determine a rough profile of the participants. Some questionnaire questions were developed to gain an understanding about the participants in the test. Questions like "Do you rent or own your home" or "do you perform any home repairs yourself" may give in site as to how interested a participant may be in this product (a person who may do their own home repairs may be more interested in a product than a person who rents their home).
Other questions had to do with the participants understanding of measurements. While it was not critical to the usability test if participants understood how to read a tape measure, understanding that measurements exists in feet and inches (as this was what the product was set to in this usability test) was critical to understanding what needed to be done in the usability test and what information was displayed on the Laser Tape's screen.
The questionnaire also included a question about age that was non-age-specific, but rather was used to determine a range of ages of test subjects.
After completing the "Pre-Test Questionnaire, participants were led into the testing environment (one at a time) and asked to complete three tasks. The first being, to compute the area of a give space, second compute the volume of a give space and last, add several measurements to produce one overall measurement. The administrator of the usability test led each participant through theses test (area, volume and addition of measurements). The administrator did not lead the participants to answers but rather pointed to the distances (marked by letters and numbers in the testing environment) and answered any questions that participants had. If a participant was completely stumped on how to operate the device (laser tape) the administrator did make suggestions to keep the test moving forward and to keep the frustration level to a minimum. Notes about each test were recorded in the same manner on a scripted "Observation Data" form.
Upon completion of the test, participants were thanked and asked if they had any questions for the test administrator about either the test or the product they were testing. Participants were again reminded that their name would not appear on any published information and any personal information (i.e. name) would be kept confidential.
The product picked for this usability test was the Strait-Line Laser Tape produced by Newell Rubbermaid under the name of Irwin Tools. The laser tape has three main functions, which are; calculate the area of a given space, calculate the volume of a given space and to add various measurements. This device also has the means to store and retrieve measurements using a memory input and memory recall functions ( these functions were not included in this usability test). The laser tape does not actually use a laser to "read measurements" but rather uses a laser to aid in the identification of what point needs to be measured and then sends a "wave" out of its "ultrasonic sensor" which bounces off the target and back to the laser tape, which then produces a measurement. A complete description of the product along with the directions for use can be found by clicking on the following link. Laser Tape
A pre-test survey was conducted of those people who choose to take part in the usability test for the Laser Tape. The following data was derived from the Pre-Test Questionnaire
1. 8/8 people who elected to take part in this usability test owned their home.
2. 5/8 subjects stated that "general maintenance" was the level of home maintenance that they preformed while 2/8 stated that their level was at the "moderate level and one subject fell into the "extensive" category (please refer to the pre-test questionnaire for categories explanations).
3. Level of comfort when reading a tape measure, 6/8 subjects felt very comfortable while 2/6 were somewhat comfortable.
4. 5/8 subjects thought that they would purchase a product that helped them make measurements, while 3/8 stated that they would not.
5. 4/8 of the subjects stated that they could recall the formula for calculating volume, while 4/8 said they could not.
6. 7/8 subjects stated that they could remember the formula for computing the area of a give space.
7. The range of ages of people who choose to participate in this usability test ranged from 30 to 60 years of age.
8. 5/8 people who took part were female, while 3 were men.
Results from this Usability Test resulted from the observation of people (volunteers) while performing pre-planed test in a controlled atmosphere. The atmosphere in this particular test is a "classroom" type room with ample of overhead lighting and a bank of windows on the East side of the room which provided natural light. A diagram of the testing environment can be found in the appendix or by clicking the following link, "Testing Environment".
The results of this test were recorded by the person conducting the test on the Observation Data sheet. This sheet insures that reactions to how the subjects reaction to each of the tested areas are recorded in the same manor. The following is the data results that was recorded during the usability test for the laser tape.
1/8 subjects could turn the laser tape on without difficulties,1/8 subjects turned the laser tape on but pushed a lot of buttons first before turning it on while 5/8 subjects could not turn the product on with out the help of the test administrator.
The most common things the subjects did (when determining how to turn it on) was to turn the laser tape from side to side and over looking for an "ON" button or switch.
4/8 subjects could set the laser tape to the "area" mode, while 3/8 subjects could not set the device to calculate area. From observation it seems as though users did not see both the screen and the interface at the same time to know if they were in the area mode.
7/7 subjects could produce measurements with this device to either calculate area volume or others.
1/8 subjects placed the laser tape in the correct manor so as to produce a accurate measurement (as outlined on the device). 6/7 subjects did not hold the device in the proper manner which resulted in incorrect measurements. Many of the subjects (all but one) placed their back to the point from which they wanted to measure and held their arm out to obtain a measurement. Others thought that they had to bounce the laser off one point to another to produce measurements.
The laser tape turns itself off after 30 seconds of non-use. 7/7 subjects remembered how to turn the device back on once it had shut itself "off".
6/7 participants could set the laser tape to the mode to calculate volume, 1/7 could not.
7/7 subjects could not perform this function. 7/7 subject repeatedly pressed the +/= button to set the laser tape in the mode to add measurements. Each time they did so the screen produced an Err message which led the subjects to press other buttons to switch the mode.
This did not present any issues with any of the test participants.
6/7 subjects did not see the molded impression at the handle end of the device which reads "Measure From Base".
5/7 subjects had difficult time reading the screen at the same time when either making measurements or placing the device in a different mode
Participants were asked to perform three exercises in this usability test; the first being to calculate the area of a give space, the second to calculate the volume of a give space and last, to add three measurements (measured in length) to produce one overall measurement. The following table represents two sets of data; the first (outlined in yellow) are the actual measurements recorded by the test administrator, the second set (outlined in light blue) is the data recorded by the test participants.
|Actual Calculations||109.125 Sq Ft||9432.225 Cu Ft||49' .333"|
Addition of Measurements
|1||117'.54Sq Ft||974.33 Cu Ft||49.5|
|2||87.83Sq Ft||688.97 Cu Ft||44.5|
|3||108.72Sq Ft||899.82 Cu Ft||48.7|
|4||91.28Sq Ft||419.18 Cu Ft||46.7|
|5||72.76Sq Ft||315.07 Cu Ft||43.6|
|6||110.65Sq Ft||982.0 Cu Ft||49.5|
|7||99.75Sq Ft||909.35 Cu Ft||48.9|
Four major problems arose when conducting the usability test for the Strait-Line Laser Tape which were;
1. Turning the product "ON".
2. Setting the "base point" of the laser tape at the point at which measurements need to be taken from.
3. Setting the device to "add measurements".
4. Accuracy of measurements.
1. Since the "Read" button is the actual "ON" button, a solution that would aid the consumer in knowing where to find the "ON" key would to add the word "ON" under the word Read on the Read button such as the following:
2. Getting an accurate measure with this device starts with the placement of the device, all but one subject's measurements were skewed because of placement of device. Many of the subjects stated that they could not or did not see the "Measure from Base" imprint at the base of device. One possible reason for subjects overlooking this key piece of information is that the color of the imprint is the same as the base. Having the imprint a different color may solve this issue. The following is an example of the difference coloring the imprint may make (color was added by test administrator)
|No color added||Color added (by test administrator)|
7/7 subjects were not able to set this device to mode to add measurements. When the subjects tried to get this device into this mode they pressed the +/= button which produced an Err reading. The Err reading let the user know they had made a mistake but did not lead them to a solution. With this being one of the main functions of the laser tape a separate key for this function like the area or volume key would make this function more assessable. Another possible solution would produce a message on the screen like "Hold Read Key" or something that would lead the user to the correct method to get the device in the desired mode.
Many of the subjects had errors in their measurements mainly due to not placing the device in the correct position (as noted above). This was mainly due to the fact that subjects did not see the "Measure From Base" molded into the handle. Even if the subject did place the device in the correct manner to obtain measurements the Strait-Line Laser Tape might not have given correct measurements. Apparently this product has had some issues in reading accurate measurements as noted by the customer reviews of this product hosted by amazon.com . It is not known whether these people who posted their comments on Amazon's web site knew that the laser tape had to be placed correctly in order to obtain accurate measurements.
Dumas, J. S., & Redish, J. C. (1999). A practical guide to usability testing. Exeter [u.a.]: Intellect.
Jordan, P. W., Thomas, B., Weerdmesster, B. A., & Clelland, I. L. (1996). Usability Evaluation in Industry. Bristol: Taylor Francis
Nielsen, J. (2000) Usability engineering. San Diego [u.a.]: Kauffman
U.S. Department of Health & Human Services. (2009, January 22). Learn about Usability Testing. Retrieved February 12, 2010, from Usability.gov: http://www.usability.gov/refine/learnusa.html#participants
Usability Testing. (n.d.). Research-Based Web Design & Usability Guidelines. Retrieved February 14, 2010, from Usability Testing: http://www.usability.gov/pdfs/chapter18.pdf