Testing sunscreen, an activity for grade 8

Thanks to Adam, the idea was his. It is based on the fact that tonic water contains quinine which fluoresces under ultraviolet light.

Tonic water (L) and tap water (R) lit by an insect electrocuter

This is a learning activity for grade 8 kids. Its intended outcomes are:

• Safe behaviour relating to sun exposure
• ie. declarative knowledge about SunSmart behaviour which is applied in daily life
• Declarative knowledge about sun exposure and health
• Declarative knowledge about the spectrum and ultraviolet
• Scientific method
• Experimental design
• Problem solving

http://commons.wikimedia.org/wiki/Image:Regenbogen_%28NASA%29.jpg

Requirements, tonic water, tap water, 2 glasses, glass plate, sunscreen : no screen, low SPF, SPF30+. Sunlight and incandescent light but MUCH better with a UV source like an insect killer.

This is a lesson based on guided discovery by the kids.

LESSON
Hi kids, what do you know about SunSmart ?
Prompt the kids as required, they should be able to quote the key messages:

• Slip - Clothing
• Slop - Sunscreen
• Slap - Hats
• Seek - Shade
• Slide - Sunglasses

Why do you do this?
Prompt till you elicit that sun exposure can cause health effects including skin cancer.

What is it about sunlight that does this?
Question their understanding further and elicit or explain that UV rays are the reason and that they are part of the spectrum and "more purple than purple" and hence invisible.

Hey kids, we have this really neat way of testing for ultraviolet light, the quinine in tonic water glows blue under ultraviolet light. Pour a glass of tonic water and tapwater, under sunlight there is a faint blue colour.

How do we know that the ultraviolet is making the blue colour and its not just blue water?
Wait for suggestions...
Would a different light be a way to test?
If you are lucky they will suggest artificial light. Chose incandescent lighting, well away from windows. Not fluorescent lighting, it contains UV. The blue colour is absent or very faint. At this point the kids should be convinced that a characteristic of sunlight causes the blue colour.

If you are lucky you will have an insect electrocuter or other blacklight source.
Kids, can you suggest anothe light source? Move to UV source. Wow it is really amazing!

OK kids we have 3 samples of sunscreen we want to test, any suggestions?
Typically they will suggest dissolving the sunscreen in the water, if you have time, try it, we didn't. Then they will suggest smearing it on the glass. We had a glass plate which we hinted at its use by looking hopefully at it, the kids got the hint and designed the experiment.

Glass plate smeared with 3 unidentified products, the kids were able to correctly identify moisturiser, SPF15 and SPF30

Becoming a teacher, knowledge, skills and issues, Colin Marsh

Becoming a teacher, knowledge, skills and issues, Colin Marsh

Chapter 3

Piaget (1896-1980)

A schema is a concept or framework that exists in an individual's mind. When new information causes cognitive disequilibrium or cognitive conflict, it can be resolved by assimilation or accommodation.

Learning Stages

• Children think differently at various stages

• Learning requires active involvement, mentally or physically

• Children build their own cognitive structures (my bold emphasis)

• Children think differently to adults

Sensori-motor (0-2)

Preoperational (2-7) – use symbols

Concrete operational (7-11) – still concrete thinking

Formal operational (11+) - abstract thinking , adults may never achieve in some domains

The book discusses Piaget's criticisms but cognitive load theory and explicit instruction are not mentioned.

also see:

Why Minimal Guidance During Instruction Does Not. Work: An Analysis of the Failure of Constructivist,. Discovery, Problem-Based, Experiential, and ...

Bruner

Factors in the development process

• React directly to stimuli

• Information and storage using a symbol system (language)

• Ability to describe past and future

• Systematic interactions with tutor/adult

• Language to communicate with others

Stages

• enactive – learning by doing

• iconic – imagery but not language

• symbolic – language logic and mathematics

Teachers should combine concrete, symbolic and pictorial representations (my bold)

Discovery learning. See Kirschner, Sweller and Clark above.

Vygotsky

Social constructivist – social interaction is the major determinant of learning

The ZPD is the point of optimum learning. "the distance between the actual developmental level as determined by independent problem solving and the level of potential development as determined through problem solving under adult guidance, or in collaboration with more capable peers" (Vygotsky, 1978, p. 86)

Scaffolding

Development stages (around speech)

• non verbal (0-2)

• merging thinking and speech

• Egocentric (overt) speech

• Egocentric speech becomes overt

(Following on my interest in game based learning, does the ZPD need to be provided by real people? Do peers need to be more capable or will numerous peers do OK? When a game gets as detailed as World of Warcraft, does the ability to match challenge to ability serve a similar role? Can in game agents including AI provide a ZPD?)

Other theories, Erikson, Kohlberg,

Chapter 4

Intrinsic motivation

Motivated students “are likely to be students who are confident about their own self worth” Does this explain the apparent failure of constructivist teaching to disadvantaged groups?

I would have liked the relationship between play and learning to be mentioned here.

"Games are thus the most ancient and time-honored vehicle for education. They are the original educational technology, the natural one, having received the seal of approval of natural selection. We don't see mother lions lecturing cubs at the chalkboard; we don't see senior lions writing their memoirs for posterity. In light of this, the question, "Can games have educational value?" becomes absurd. It is not games but schools that are the newfangled notion, the untested fad, the violator of tradition. Game-playing is a vital educational function for any creature capable of learning."
Crawford, The Art of Computer Game Design

and me on Johnson, Everything bad is good for you. pp1..62

Strategies to encourage intrinsic motivation

• novel situation

• personal anecdote

• challenging questions

• contradictory information

• unfamiliar examples

• case studies

I would add to this list teacher modeling good learning behaviour

“there is such a thing as becoming a good learner and therefore … teachers should do a lot of learning in the presence of the children and in collaboration with them.”

What is Logo? Who Needs It? by Seymour Papert Logo Philosophy and Implementation© Logo Computer Systems Inc. 1999

Extrinsic rewards, gold stars etc do significantly undermine intrinsic motivation.

Motivation declines in grades 7-9 but rises again in year 11 as a result of career motivation.

• Warmth and enthusiasm
• Meaningful goals
• Fostering climate
• Maintaining equity

At p44, simulations and games are mentioned see me at http://tonyforster.blogspot.com

My list

• Relevant challenge
• Authentic challenge
• The right tools SEE flow
  
• A collaborative environment ZPD