Evidence based lighting, review of classroom case studies by Natalia Lesniak

Designers Light Forum

Evidence based lighting, review of classroom case studies

Natalia Lesniak, Ute Besenecker03/28/2017

AIA/HSW Credit

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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 ofhandling, 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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LearningObjectives

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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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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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 & assessment Goal: educate,

hypothesize, research, evaluate, and report

Vision: all healthcare environments created using EBD process

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The Center for Health Design (CHD) created EDAC (Evidence-Based Design Accreditation and Certification) Goal: to educate on the process, to identify research, hypothesize, implement, gather, evaluate, and report their results Mission: to develop a community of certified industry individuals through education and assessment Vision: a world where all healthcare environments are created using an EBD process


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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Our take on it: Evidence Based Design (EBD), is a practice collecting credible evidence to influence design decisions EBD is based on scientific analysis methodology emphasizing the use of data acquired in order to inform and influence the design process The goal of EBD is to bridge the gap between research and design practices

“The definition of insanity is doing the same thing over and over again, but expecting different results.” Albert Einstein


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

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Lets go into more detail on the next slide


“EBD took hold in hospital design because of the existing evidence-based medicine culture”David Watkins, FAIA, Founding Principal of Houston-based WHR Architects

EVERWHEREFOR EVERYTHING?

And now:

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Light’s impact on subjective impressions - John Flynn late 70’s The late Flynn’s seminal work—including his “Interim Study of Procedures for Investigating the Effect of Light on Impression and Behavior” (October 1973) and “A Guide to Methodology Procedures for Measuring Subjective Impressions in Lighting” (January 1979)—explores how different light sources are perceived by building occupants. Historically associated with healthcare architecture and now... Today increasing awareness of biological and physiological impact of lighting in offices, hotels, residences, schools,...: Making inroads into being part of the process for designing schools, office spaces, hotels, restaurants, museums, prisons, retail, and even residences Decisions about physical space are based on research and data

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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Today increasing awareness of biological and physiological impact of lighting in offices, hotels, residences, schools,...: Case studies in lighting, e.g. school classroom lighting Studies into: Energy efficiency and sustainability in real world applications Emotional responses and preference (e.g., mood, subjective impression) Visual perceptions (e.g., spatial brightness, color, contrast, glare) Visual performance (e.g., acuity, accuracy, speed) Acute, non-visual impact (e.g., alertness, cognitive and physical performance) Long term, non-visual biological effects of light (e.g., circadian entrainment)

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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The independent variable is the one that is changed. According to the Center for Health Design (CHD), the evidence-based design process includes eight steps: Define EBD Goals & Objectives Find Sources for Relevant Evidence Critically Interpret Relevant Evidence Create & Innovate EBD Concepts Develop a Hypothesis Collect Baseline Performance Measures Monitor Design & Construction Measure Post Occupancy Results Analyze and critically interpret

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

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school/classroom12

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In order to illustrate the process of EBD, some case study examples by researchers from different disciplines; all investigating lighting in classrooms/ schools, particularly into non-visual impact of light on circadian rhythm, and student performance

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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Why is everybody studying light in schools? Good illustration is first case study sample What happens if school children won’t get any blue light in the morning and during the day? 9 boys and 2 girls


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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Impact of light exposure on sleep onset in middle school children Avg. of 30 minutes delay after 5 day intervention (statistical significance) Absence of short wavelength light in daytime hours shifts circadian rhythm and delays sleep onset

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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So why is this happening? Let’s look at that, next slide


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Left side shows a typical daytime spectrum with energy at all wavelength of the visible spectrum, and the right diagram shows the spectrum when wearing orange glasses

Lack of blue morning light has an impact on children’s circadian rhythm.

What happens if we add blue light or use tunable light?


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So the lack of short wavelength blue light had an impact on the children’s body clock. Suggesting they would gravitate to sleep and wake up later. What would happen if blue light is increased in the morning?


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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Elementary School, 4th Grade control and test: 27 students (fifteen boys and twelve girls) each, avg. 10 years fluorescent lighting (5000 K) vs. LED (3500 K, 5000 K, 6500 K), 500 lux Data collection, every other day for two weeks Quantitative: arithmetic problems (medium-level difficulty), 2 min Qualitative: surveys to evaluate lighting for academic and recess activity (comprehension, concentration, visual comfort, and suitability), 10 min


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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Results: (Quantitative & Qualitative) 6500 K lighting was perceived as the most appropriate for academic activity 3500 K lighting received the highest average score for recess activity No change in control group performance percentage of correct answers was the highest in the 6500 K lighting limitations


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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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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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Malmo Elementary School Changed CCT and light level throughout day Activating: 6500K, 600lx Calming: 2700K, 250lx Dialogue: 2700K, 400lx Neutral: 4000K, 500lx high in morning and after lunch, lower afternoon and late morning Results: qualitative Lighting appreciated by participants with some recommended alterations Liked high CCT and brightness to concentrate Liked low CCT and brightness to relax comments Change too quickly (noticeable, distracting) 6500K light increased headaches in 10% pupils


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

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Teachers used CCT & light level as pedagogical tool. Lower CCT & lux = calmer/more quiet students Limiations: Too many variables to deduct clear results CCT and light level always changes together Lighting changes are noticeable and evaluated as distracting Unexpected limitations of technology at the time Lighting in classroom very different from corridor Predominantly subjective comments and qualitative measures (valuable) Addition of quantitative methods and more stringent protocol could have added valuable information comment: study's objective was to explore. CCT/light level was used as a pedagogical tool.


• Cool morning light of high brightness is appropriate for academic setting.• Lighting equipment and controls still have limitations

No quantitative data and focused analysis

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• Quantitative Data to confirm subjective observations?

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Keis, et al. "Influence of blue-enriched classroom lighting on students Ѳcognitive performance." Trends in Neuroscience and Education 3, no. 3 (2014): 86-92.


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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High intensity blue-enriched light improves high school students‘ cognitive performance both acutely (1 day) and long-term (5 weeks)


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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High intensity blue-enriched light improves high school students‘ cognitive performance both acutely (1 day) and long-term (5 weeks)


• Blue-enriched white light correlates positively with improved performance.

o Both, quantitative data and qualitative data

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5. Limitations to consider

• Conflicts of interest

• Knowledge gaps

• Cost

• Uncovered impact of light

• Lighting metrics o CCT only estimates white light color appearanceo Same CCT’s can have varied spectrum and impact on visual

and non-visual systems

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Novelty factor Be critical of conflicts of interest Who funded the study? Knowledge gap between researcher and applications/designers Study results often difficult to translate to wider applications Design community unaware of studies Knowledge gap b/w medical/manufacturer research and lighting research Some med researches lack full understanding of light Lightings’ value is difficult to monetize as its ubiquitous Focus is on immediate payback�Cost of system installation, maintenance Full extent of lighting impact on people is only being uncovered recently Lot of research does not connect yet to design Lighting metrics understanding, e.g. CCT vs spectrum in above studies


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Same CCT can have different spectra and appearance


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

VλMelλ

White LED

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Photopic

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Shortcoming of CCT particularly relevant in evaluating non-visual impact of light While vision based on cone receptor sensitivity, photoreceptor responsible for non-visual impat has different sensitivity


• 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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Use of lighting metrics that are based on 2-degree field-of-vision, however exposure is full-field Use of 2d screen pictures as substitute for real immersion Use of CCT (or x,y) as substitute for spectral information

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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Interdisciplinary collaboration in the best remedy, to avoid limitations

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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EBD buzzword, so we wanted to discuss relevance of a structured approach, encourage open interaction between design and scientific research and use of mixed methods, depending on the objective

Question and Discussion?

[email protected]@lsgc.com

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Questions? You can also email us

mailto:[email protected]

mailto:[email protected]

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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This concludes The American Institute of Architects Continuing Education Systems Course

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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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„Color is an event that only takes place through a network of exo-relations between the molecular endo-composition of the object, Take any of these elements away and color puffs out of existence. As such, color, as an exo-quality is a genuine agency of these three agencies being woven together. It is not the cup that is colored, but rather the entanglement of these agencies that produces color as an event.” Monochromatic narrow-band light performs differently from polychromatic broadband light.

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 201337

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Human beings are inherently rhythmic, many body functions are regulated by a “master clock” which influences:�NON-VISUAL EFFECT OF LIGHT •Sleep/wake cycle, Hunger/ digestion, Thermoregulation, Rise and fall of bloodstream hormone levels Entrainment happens predominantly through light/dark cycle (evolved with day/night rhythm) •In 24/7 darkness, rhythm on average 24.25 hrs •Individual differences Master clock resides in Suprachiasmatic Nucleus (SCN) •Responsible for hormone secretions CIRCADIAN Rhythm most sensitive to short wavelength light 470-480nm (Blue)

https://www.researchgate.net/journal/1741-7015_BMC_Medicine


• 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 t238

Barkmann, et al. "Applicability and efficacy of variable light in schools." Physiology & behavior 105, no. 3 (2012): 621-627.

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Higher intensity, blue-enriched daytime light improves student concentration and reading over 4 weeks (3rd grade and 10th grade)

Evidence based lighting, review of classroom case studies by Natalia Lesniak

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