0LAUK0 2018Q1 Group 2 - Prototype User Testing

From Control Systems Technology Group

Jump to: navigation, search

This page is part of the research done by 0LAUK0 2018 Q1 Group 2, our main page can be found at PRE2018 1 Group2. During week 6 of the project, the tests were revised. The previous iteration of the tests can be found in the section "old tests".


Contents

Introduction

Once the design is ready, it needs to be tested by independent users. The monitor needs to be user- friendly, so a test plan should be made to check whether it is. The requirements are mainly about ethical and physical issues. The monitor should not cause ethical problems and it should be physically pleasant for the user to use the monitor. An idea for testing our monitor could be to place it in MetaForum, and let students and teachers use it. Again, here one can distinguish critical issues from high, medium and low issues. Any critical issues shall be dealt with first, then the high issues, etc. The goal is again to get zero critical and high issues and as less medium and low issues as possible. In the end, a justification of our device will follow.


Requirements

  • Screen not moving too slow, but not too fast neither. Optimal would be that once the screen starts moving, it will reach the correct position within ‘x’ seconds. It will move with a constant velocity (or as constant as possible). Screen will move in three parts; first sideways, then vertically and then horizontally.
  • Screen not too sensitive (an optimal responding time would be ‘x’ seconds).
  • As less noise as possible.
  • Cameras delete all frames made.
  • From a certain angle, it should be impossible to see what is on the screen (privacy).
  • It must be possible to operate the screen manually.
  • If the user has a wrong posture, the screen will give a warning. When the warning is not answered, the screen will turn off. (Good or wrong posture is determined by input parameters.
  • Screen moves by itself to adjust the posture of the user.
  • One needs a security code to be able to install and/or adjust the input parameters.


Revised tests

Responding to a Wrong Posture

The goal of doing these tests, is finding out what the preference of the user is, regarding how the monitor should respond when the user is having a wrong posture. The response that turns out to be most convenient will then be set as the standard response of the device. The other responses will still be available as custom settings.

Scenario:

The user is sitting behind the monitor, having a wrong posture.

Expected outcomes:

  • The screen will be lightened or dimmed, depending on whether the user is too close or too far away. If the user is too close, the screen will brighten up, if the user is too far away, the screen will dim.
  • The monitor will come up with a visual reminder (like a pop-up, a notification, etc.).
  • The device will play an audio reminder, a sample that starts to play when the user is in an incorrect posture.
  • The rumble motors in the chair will be activated and the chair starts to rumble (akin to rumble features in present modern video games).
  • The screen will move towards or away from the user, depending on whether the user is too close or too far away. If the user is too close, the screen will move towards the user, if the user is too far away, the screen will move away from the user.

First it should be tested whether these scenarios work at all (these tests could be performed by us), and then the users could be used to determine a favourite way of responding.

Monitor Moves Along

The goal of doing these tests, is finding out what moving speed of the monitor is the most convenient for the user. This speed will then be set as the default speed. The other speeds could still be available as custom speeds.

Scenario:

The user moves away an enough distance to not maintain an optimal position for the monitor.

Expected outcomes: The monitor will follow along with 1 cm/s, 2 cm/s, 3 cm/s, etc. First it should be tested (by us) whether these scenarios work in the first place. Then the users could be used to determine an optimal moving speed. An additional test could be made concerning the vibration of the monitor when moving (these tests could be performed both by us and the users).

Scenario:

The same as just before.

Expected outcome:

The monitor doesn’t vibrate when moving, the view of the monitor is not disturbed.

Unit tests

One of us will take place behind the monitor and do the following tasks:

  • Sit too far away; to be expected is that the monitor will move away from us in order to make clear that we are too far from the screen.
  • Sit too close; to be expected is that the monitor will move a little bit towards us in order to make clear that we are too close to the screen.
  • Sit in a wrong position; to be expected is that the monitor will at least have an internal warning such that it knows that our posture is incorrect.
  • Sit in a correct position and gently move to the right, left, forward, backward; to be expected is that the monitor will follow along.
  • Sit in a correct position and pick something up from the ground; to be expected is that the monitor will recognize this as a spontaneous movement and thus will ignore it.


Old Tests

Physical tests

Some of the tests that could be done regarding the requirements above will be omitted since that these already have been described in the first test plan (tests like making the actuator less noisy, installing custom made thresholds and thus operating the screen manually, etc.). Of course, everything described in the first test plan should still be valid when testing the device on the real users.

1. The user moves within response time and exceeding the maximum deviation.

Expected outcome: The screen will follow along after ‘a’ seconds (response time) and reach the correct position within ‘x’ seconds, moving with a (as far as possible) constant velocity.
Obtained outcome: …

2. The user is sitting behind the screen, having a wrong altitude.

Expected outcome: The screen will give a warning about the wrong posture of the user. If the user corrects his/her posture correctly, the warning disappears. If the user doesn’t correct his/her posture, the screen will turn off.
Obtained outcome: …

3. The user is sitting in a correct position for a ‘x’ amount of time.

Expected outcome: After a ‘x’ amount of time, the screen will adjust itself to a new optimal position.
Obtained outcome: …

Ethical Tests

1. The user uses the monitor for a ‘x’ amount of time, with the camera running.

Expected outcome: All frames the camera has made are deleted (instantaneously).
Obtained outcome: …

2. Someone stands behind the user and walks to the right/left, looking at the screen.

Expected outcome: From a certain angle, the screen will not be visible anymore.
Obtained outcome: …

3. The user wants to install/change his/her input parameters.

Expected outcome: The device asks for a personal security code in order to be able to get access to the input parameters.
Obtained outcome: …

Concrete Scenarios

Below the concrete scenarios can be found, that were to be executed. The first user test has actually been realised, the second user test could be executed in case of further investigation.

User Test 1

Permission is asked to an independent user to install our cameras on his/her laptop. Then, the user is asked to just make some homework, while sitting behind the laptop. We will film the user for about 30 minutes. From the frames that have been made, some conclusions can be drawn (assuming that our user is behaving like an average person) about which movements are frequently made by users and which positions are taken the most.

User Test 2

An independent user is asked to make some homework behind our monitor. The exercises will be attached to our monitor and the user can begin studying as he/she normally would do. While studying, the user is bound to move sometimes, or take some other positions. It will be tested whether our monitor responds correctly to the movements of the user. Afterwards the user will receive a survey where it will be asked what his/her experience with our monitor was (e.g. what was good, what was bad) and the user will be asked about what he/she would like to see improved to our monitor.

User Survey

To complete the second user test, this test could be followed by a survey where the user can state what his/her experiences with the device were. The user can give grades from 0 (really bad) up to 10 (really good).

  • 1. The monitor triggered me to sit in the correct position.

0-1-2-3-4-5-6-7-8-9-10

  • 2. The movements of the monitor didn’t distract/annoy me.

0-1-2-3-4-5-6-7-8-9-10

  • 3. If applicable, what about the monitor did distract/annoy you?

  • 4. After working one hour with the monitor, I have less RSI symptoms than when I’m working with a normal computer.

0-1-2-3-4-5-6-7-8-9-10

  • 5. I am comfortable working with this monitor, even when I know that a camera is watching me to register my movements.

0-1-2-3-4-5-6-7-8-9-10

  • 6. Is there anything you would improve to this monitor?

  • 7. I found it pleasant that the monitor adjusts itself to my posture.

0-1-2-3-4-5-6-7-8-9-10

  • 8. The text on the monitor was always good readable.

0-1-2-3-4-5-6-7-8-9-10

  • 9. What was your overall experience with the monitor?

0-1-2-3-4-5-6-7-8-9-10

  • 10. I would consider buying this monitor.

0-1-2-3-4-5-6-7-8-9-10

Proof of Effectiveness

One of the most important things in this project of course is to get proof of that our device will actually succeed in preventing RSI. If our device would not take the known actions for preventing RSI into account, it could become a failure. Therefore, it is important to have a justification of what our device does and why.

In order to maintain and promote ones health, a good balance between activity and rest is necessary. Rest pauses are helpful for recovery of load-induced strain and prevention of fatigue. (1) By giving the monitor a function to give a warning after the user has worked for a ‘x’ period of time, or when desired even shut down, this can be achieved.

The risk of RSI can be minimised by understanding the basic principles of good positioning. (2) This would be the positions as described before (screen at approximately 50 cm distance, maintaining the right viewing angle, etc.). By giving the device these positions as default settings, the risk of getting RSI should be reduced.

Forceful exertion often causes neck MSDs (Musculoskeletal Disorders). (3) Once the device takes the right position, the user can look relaxed to the screen, without exerting his/her neck. This problem could therefore be solved. Furthermore, neck MSDs could also be caused by maintaining a static posture. By taking initiative and adjust its position by itself, the monitor could help the user preventing this problem.

The above scenarios already show that in theory, the monitor should be able to solve all kinds of problems. This could be verified by testing the device out and if necessary approve it.

References

  1. Luttmann, A., Jäger, M., Griefahn, B., Caffier, G., Liebers, F. & Steinberg, U. Preventing Musculoskeletal Disorders in the Workplace. 2003. Retrieved from: [1]
  2. Hendrickson, M. Repetitive Stress Injury: Protect Your Hands Against Repetitive Stress Injuries. 2018. Retrieved from: [2]
  3. Bernard, B.P., Putz-Anderson, V., Burt, S.E., Cole, L.L., Fairfield-Estill, C., Fine, L.J., Grant, K.A., Gjessing, C., Jenkins, L., Hurrell, J.J., Nelson, N., Pfirman, D., Roberts, R., Stetson, D., Haring-Sweeney, M. & Tanaka, S. Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiologic Evidence for Work-Related Musculoskeletal Disorders of the Neck, Upper Extremity and Low Back. Retrieved from: [3]
Personal tools