This document provides an overview of an evidence-based design forum on classroom lighting case studies. The presentation discusses evidence-based design and how it can be applied to the lighting industry. Several classroom lighting case studies are summarized that illustrate how data can be collected and analyzed to study the impact of different lighting designs and metrics. The case studies examined topics like the impact of blue light exposure and CCT on student performance, sleep, and preferences. Limitations of the studies are also reviewed. The presentation concludes with discussing collaboration needs and questions around evidence-based design practices.

1. Designers Light Forum
Evidence based lighting,
review of classroom case studies
Natalia Lesniak, Ute Besenecker
03/28/2017
AIA/HSW Credit
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2. Credit(s) earned on completion of this course will be reported to AIA CES for
AIA members. Certificates of Completion for both AIA members and non-
AIA members are available upon request.
This course is registered with AIA CES for continuing professional education.
As such, it does not include content that may be deemed or construed to be
an approval or endorsement by the AIA of any material of construction or
any method or manner of
handling, using, distributing, or dealing in any material or product.
___________________________________________
Questions related to specific materials, methods, and services will be addressed at the conclusion of this
presentation.
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3. Learning
Objectives
1. Gain an understanding of what is Evidence-based design
2. Identify the research & design methods for EBD
3. Gain an understanding what tools are available to collect and analyse information/data
4. Discuss and gain an understanding how EBD practices can be applied in the lighting
industry
At the end of the this course, participants will be able to:
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4. 1. What is Evidence-based design?
2. How can EBD practices be applied in the lighting industry?
3. What research & design methods are used in EBD.
4. Case study samples to illustrate tools available to collect
and analyze data.
5. Limitations to consider.
Objectives in Other Words
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5. 1. What is Evidence-based design?
The Center for Health Design (CHD) created EDAC (Evidence-Based
Design Accreditation and Certification)
Mission: community of
certified industry
individuals through
education & assessmentGoal: educate,
hypothesize, research,
evaluate, and report
Vision: all healthcare environments
created using EBD process
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6. 1. What is Evidence-based design?
Evidence-Based Design
(EBD) is the process of
basing decisions about the
built environment on
credible research to
achieve the best possible
outcomes in real world
application.
CHD, 2009-2017
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7. “The definition of insanity is doing the same thing over and over
again, but expecting different results.” Albert Einstein
1. What is Evidence-based design?
Evidence based design gives
the opportunity to:
1. identify a problem; theorize solution
2. create study to test a theory on site
3. evaluate results
4. apply an improved solution into the environment
5. post occupancy survey
6. new study based on the above
ImprovedBuiltEnvironments
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8. 1. What is Evidence-based design?
“EBD took hold in hospital design because of the existing
evidence-based medicine culture”
David Watkins, FAIA, Founding Principal of Houston-based WHR Architects
EVERWHERE
FOR EVERYTHING?
And now:
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9. 2. How can EBD practices be applied in the lighting
industry?
Studies into:
1. Energy efficiency and sustainability
2. Emotional responses and preference
3. Visual perceptions
4. Visual performance
5. Non-visual impact (acute)
6. Non-visual biological effects of light (long term)
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10. 3. What research & design methods are used in EBD?
o Define a goal and objective
• What specifically should be tested and improved?
o Get informed
• Background research to know what evidence exists already
o Develop a study design, intervention and test procedure
• Hypothesis how intervention would impact target user
• Define dependent and independent variables
• Data collection methods in line with hypothesis
• Be aware of confounds that might impact your data
o Collect data
• in existing condition (baseline)
• in new condition (test)
o Analyze and critically interpret
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11. 3. What research & design methods are used in EBD?
Quantitative data
Qualitative or quantitative data collection (or mixed methods)?
o Interviews
o Description, observation
o Photographs, video
Good for explorations, targeted to explore
questions, not tied to a particular hypothesis
Qualitative data
o Numerical / measured data
o Some questionnaires qualify
o Statistical analysis
Good for measurable evidence and repeatable
experimental data (based on average) 11

12. school/classroom
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13. 4. Case study samples to illustrate tools available to
collect and analyse data
Impact of light exposure on sleep onset in middle
school children
● 11 students (13–14 years)
Intervention:
● orange glasses from early morning until 3 pm,
for five days
Data collection:
● Saliva to test for changes in circadian timing,
Friday before and Friday after
Figueiro, Mariana G., and Mark S. Rea. "Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students."
Neuro endocrinology letters 31, no. 1 (2010): 92.
pm
x 5 days
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14. 4. Case study samples to illustrate tools available to
collect and analyse data
Impact of light exposure on sleep
onset in middle school children
Results:
● Avg. of 30 minutes delay
(5 day intervention)
● statistical significance
Figueiro, Mariana G., and Mark S. Rea. "Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students."
Neuro endocrinology letters 31, no. 1 (2010): 92.
Cumulative frequencies of DLMO for the students
before and after the orange glasses intervention.
Before After
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15. Let’s look at the spectrum more closely...
What was learned? Next Step?
Absence of blue morning light has an impact on children’s circadian rhythm
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16. What was learned? Next Step?
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17. Lack of blue morning light has an impact on children’s circadian rhythm.
What happens if we add blue light or use tunable light?
What was learned? Next Step?
ImprovedBuiltEnvironments
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18. 4. Case study samples to illustrate tools available to
collect and analyse data
Elementary School, 4th Grade
• 2 groups: control and test
27 students (ave. 10 yrs old)
• fluorescent lighting (5000 K)
vs.
• LED (3500 K, 5000 K, 6500 K)
• 500 lux
Data collection
• arithmetic problems, 2 min
• surveys to evaluate lighting for academic
and recess activity, 10 min
Choi, Kyungah, and Hyeon-Jeong Suk. "Dynamic lighting system for the learning environment: performance of elementary students."
Optics express 24, no. 10 (2016): A907-A916.
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19. 4. Case study samples to illustrate tools available to
collect and analyse data
Results:
● 6500 K – most appropriate for academic
activity
● 3500 K – highest ave. score for recess
activity
● % of correct answers was the highest in the
6500 K lighting
Experimental design is important
● Study tested CCT in morning
● Only listed CCT
● What about other lighting metrics?
Choi, Kyungah, and Hyeon-Jeong Suk. "Dynamic lighting system for the learning environment: performance of elementary students."
Optics express 24, no. 10 (2016): A907-A916.
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20. What was learned? Next Step?
ImprovedBuiltEnvironments
Cool appearing morning light appropriate for good academic performance.
no other lighting characterization than CCT
Can this be validated in another setting?
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21. 4. Case study samples to illustrate tools available to
collect and analyse data
Malmo Elementary School
• Changed CCT and light level throughout day
• high in morning and after lunch, lower afternoon
and late morning
Data collected:
• Interviews and questionnaires
Results:
• Liked high CCT and brightness to concentrate
• Liked low CCT and brightness to relax
Karlsson, Tove . 2015. Evidence based design of light characters and automatic light variation, for a classroom in Malmö.
Master’s Thesis, Lighting Laboratory, KTH, Royal Institute of Technology, Stockholm.
o Activating: 6500K, 600lx
o Calming: 2700K, 250lx
o Dialogue: 2700K, 400lx
o Neutral: 4000K, 500lx
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22. 4. Case study samples to illustrate tools available to
collect and analyse data
Limitations:
• Too many variables
• Multiple variables change together
• Lighting changes are noticeable/distracting
• Corridor light remained the same
• Only qualitative results
Exploratory study that would benefit from focused
quantitative follow-up
Karlsson, Tove . 2015. Evidence based design of light characters and automatic light variation,
for a classroom in Malmö. Master’s Thesis, Lighting Laboratory, KTH, Royal Institute of Technology, Stockholm.
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“I think that it is primarily active mode that works in class.
[...] I find it difficult to see when I should use "calming
light" during lessons.” Teacher

23. What was learned? Next Step?
• Cool morning light of high brightness is appropriate for academic setting.
• Lighting equipment and controls still have limitations
No quantitative data and focused analysis
ImprovedBuiltEnvironments
• Quantitative Data to confirm subjective observations?
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24. Keis, et al. "Influence of blue-enriched classroom lighting on students Ѳcognitive performance." Trends in Neuroscience and Education 3, no. 3 (2014): 86-92.
4. Case study samples to illustrate tools available to
collect and analyse data
Quantitative data study:
• 58 high school students
• Impact of blue-enriched daytime white light
• LED 14,000K + 4000K vs
• Fluorescent 3000K /4000K
Standardized tests for:
• Cognitive performance
o processing speed
o concentration
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25. 4. Case study samples to illustrate tools available to
collect and analyse data
1 day 5 weeks
Keis, et al. "Influence of blue-enriched classroom lighting on students Ѳcognitive performance." Trends in Neuroscience and Education 3, no. 3 (2014): 86-92.
Test Results:
• Less errors
• Faster test processing
• Higher cognitive performance
Questionnaire results:
• Standard lighting preferred
• But test lighting better for academic
performance and alertness (keep)
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26. What was learned? Next Step?
• Blue-enriched white light correlates positively with improved performance.
o Both, quantitative data and qualitative data
ImprovedBuiltEnvironments
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27. 5. Limitations to consider
• Conflicts of interest
• Knowledge gaps
• Cost
• Uncovered impact of light
• Lighting metrics
o CCT only estimates white light color appearance
o Same CCT’s can have varied spectrum and impact on visual
and non-visual systems
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28. 5. Limitations to consider
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29. 5. Limitations to consider
What metrics and data collection might have
been more meaningful?
• Spectrum vs. CCT
• Melanopic - Photopic ratio
Andersen, Marilyne, John Mardaljevic, and Steven W. Lockley, 2012
Melanopic
Vλ
Melλ
White LED
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Photopic

30. 5. Limitations to consider
• CCT based on central fovea (2 degrees)
• Light Level based on central fovea (2 degrees)
Photoreceptors involved in non-visual impact are predominantly present in
periphery of the retina
This is 2°
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31. Collaboration
Interdisciplinary collaboration necessary to advance lighting research &
evidence based lighting:
• Medical researchers and practitioners
• Lighting researchers in human factors and technology
• Cognitive and visual neuroscientists
• Lighting manufacturers
• Lighting designers
• Consider and consult specific user group
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32. Evidence-based DESIGN? (Buzzword?)
● Is certification necessary (EDAC)?
● Is research method education necessary in the design
disciplines?
○ Good designers ALWAYS do research
■ Methods vary from discipline to discipline
○ Studies are typically limited to a particular set-up and
hypothesis
■ might not be as generalizable as many might think
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33. Question and Discussion?
natalia@LumenArch.com
ubesenecker@lsgc.com
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34. 1. What is Evidence-based design?
2. How can EBD practices be applied in the lighting industry?
3. What research & design methods are used in EBD?
4. Case study samples to illustrate tools available to collect
and analyse data.
5. Limitations to consider.
Objectives revisited
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35. This concludes The American Institute of Architects Continuing
Education Systems Course
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36. Wait wait, what is…
SPD, non-visual effect of light, a circadian rhythm?
•Radiant energy capable of exciting the retina and producing a visual sensation.
•The visible portion of the electromagnetic spectrum extends from about 380 to 780 nm
(IESNA definition)
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37. Wait wait, what is…
SPD, non-visual effect of light, a circadian rhythm?
Hickie IB, et al. "Manipulating the sleep-wake cycle and circadian rhythms to improve clinical management of major depression“ BMC Medicine 11(1):79 · March 2013
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38. 4. Case study samples to illustrate tools available to
collect and analyse data
• Higher intensity, blue-enriched daytime
light improves student concentration and
reading over 4 weeks (3rd grade and 10th
grade)
Quantitative data focused studies:
Impact of blue-enriched
daytime white light Control Group
Intervention Group
Control
Intervention
t1 t2
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Barkmann, et al. "Applicability and efficacy of variable light in schools." Physiology & behavior 105, no. 3 (2012): 621-627.