This document provides recommendations for subjectively evaluating sensory experiences. It discusses different test setups and stimulus methods, including single stimulus and double stimulus studies. Single stimulus continuous quality evaluation was found to stress participants and an indirect voting device is recommended. Double stimulus studies like degradation category rating and double stimulus continuous quality scale were found to be more suitable for assessing sensory enhancements. Combining stimulus methods requires caution to avoid biases.

1. RECOMMENDATIONS FOR THE
SUBJECTIVE EVALUATION OF
SENSORY EXPERIENCE
Benjamin Rainer, Christian Timmerer,
and Markus Waltl

2. TABLE OF CONTENTS
 Introduction
 Motivation
 Test Setup
 Single Stimulus Studies
 SSCQE + ACR
 Double Stimulus Studies
 DCR
 DSCQS + single stimulus

3. INTRODUCTION
• Multimedia enriched by sensory effects like wind,
vibration and light
 For quality degradations by lowering the bitrate of the actual video
sequence
 For genres like action, documentary, commercial, and sports
 Intensity of emotions are influenced
• Passive emotions are decreased
• Active emotions are increased

4. MOTIVATION
 How has the test setup and design to be, for subjectively
assessing the QoE of sensory experience?
 Which stimulus methods are useful for subjectively
assessing sensory experience?
 Single stimulus?
 Double stimulus?
 Does mixing up single stimulus and double stimulus end
up in a bias when assessing sensory experience?

5. TEST CONDITIONS, TEST SETUP, AND
TEST DESGIN
 In-Lab assessments
 Setup according to ITU-R BT.500-11/13
 Ergonomic placement of keyboard, mouse and seat
 Test setup

6. TEST CONDITIONS, TEST SETUP, AND
TEST DESGIN
 Textual introduction
 Each participant is presented the same introduction
 Allows for training phases
 Includes demographic questions aswell as the possiblity for the
participants to give feedback
 Supports different test methods

7. SINGLE STIMULUS EVALUATION -
SSCQE + ACR
 Single Stimulus Continuous Quality Evaluation
with categorical rating scale
 Combined with an Absolute Category Rating (ACR)

8. SINGLE STIMULUS EVALUATION -
SSCQE + ACR
 24 Participants
 11 female
 13 male
 Assess whether sensory effects unmask quality degradations
 Quality in terms of bitrate
 Dedicated voting device
 Stressed the participants for the SSCQE part
 No intiuitive handling of the voting device
 More intuitive voting devices should be used
• Indirect devices e.g., EEG
 Assessing Sensory Experience with SSCQE is not recommended

9. SINGLE STIMULUS EVALUATION -
SSCQE + ACR
Earth Sequence Babylon A.D. Sequence

10. DOUBLE STIMULUS EVALUATIONS -
DCR
 Degradation Category Rating
 Double stimulus with a categorical scale
• veryannoying (1), annoying (2), imperceptible (3),
littleenhancement (4) andbigenhancement (5)
 Assess the enhancement of sensory effects
 No randomization of reference and test condition
 Reference can be easily identified (no effects)
 25 Participants
 12 female
 13 male

11. DOUBLE STIMULUS EVALUATIONS -
DCR

12. DOUBLE STIMULUS EVALUATIONS -
DSCQS
 Double Stimulus Continuous Quality Scale
 Modified by combining it with a single stimulus
• After each stimulus presentation emotion rating
• Double stimulus for the enhancement of QoE
 The rating scale for emotions and the
enhancement in QoE was on an interval of
[0,100]

13. DOUBLE STIMULUS EVALUATIONS -
DSCQS
 In total 68 participants
 36 female
 32 male
 Conducted at three sites
 AAU (Austria)
 UOW (Australia)
 RMIT (Australia)
 For identyfing a bias of the combined test method studies from UOW
and RMIT were used

14. DOUBLE STIMULUS EVALUATIONS -
DSCQS
 No significant difference between the means of RMIT and UoW

15. CONCLUSIONS
 Single stimulus method with categorical rating
scales are suitable for assessing the sensory
experience
 SSCQE may stress the participants, the voting
device plays an important role
 Even with an intuitive voting device particpants may be
stressed due to effects and the task of the continuous
voting
 Indirect voting devices such as EEG should be used

16. CONCLUSIONS
 The DSCQS was modified to fit the needs of an
subjective quality evaluation in the domain of
sensory experience
 The DCR method was used as defined, only the
rating scale had to be changed slightly (from
impairment to enhancement)
 When combining stimulus methods caution is
advised that no bias is introduced

17. THANK YOU!
QA