Assessment focuses
AF2, AF3, AF4
Context
After discussion about the work of Northumbria Water in getting water from the Kielder Reservoir to our homes, pairs of pupils were each given a tablespoon of mud from the school field and they mixed this with 200 ml of water. They were asked to get the muddy water as close to ‘drinkable’ as possible, without using any further water.
A wide selection of materials was available. This included:
- sieves
- several kinds of fabric
- high and low quality filter paper
- funnels
- beakers
- buckets.
The evidence
At the top of the page, there is a photo of a persons hand holding a beaker filled with brown liquid.
Under this photo the child has written the following notes:
Filtering
Professor Scott and I were presented 1 tbl school field mixed with 200ml water. To clean it we used the following equipment:
sieve
fabric (2 kind)
cheapr filter paper
Top quility filter
funnel
beaker
Under these notes the child has drawn a filter diagram, with annotations, to represent how they filtered the water. The child has drawn a 2D beaker with lines that represent a funnel and filter paper at the mouth. The child has drawn mud rapoped in the filter, a drop of water coming out of the funnel, and sediment at the base of the beaker. The following annotations have been written:
Sediment [a line points to the sediment at the base of the beaker]
Cleaned water [a line points to the drop of water coming out of the funnel]
funnel [a line points to the funnel at the mouth of the beaker]
filter paper [a line points the filter which appear just above the funnel]
mud trapped in filter [a line points to mud trapped in the base of the filter]
beaker [a line points to the beaker]
Under the filter diagram, the child has written the following notes:
'A filter works by leaving most. A filter works by cleaningwater by little hole in it and gets rid of the mud.
A filter works by trapping mud in it and lets water through by little holes.
After filtering we left our water to stand for a few days. This helped clean the water even more because the mud particles fell to the bottom by gravity pulling it donw.
My result-:'
The child has drawn an illustration of a rectangle with annotations. About one fifth of the left hand side of the rectangle is coloured in, the rest is blank. The annotations around the rectangle read:
Before clearning [a line points to the far left hand side of the rectangle]
Drinkable [a line points to the far right hand side of the rectangle]
our filter water [a line points to an area of the rectangle, about four fifths of the way across. Closer to 'drinkable' than 'before cleaning']
Under this illustration the child has written:
I would have improved my result by using U to filter papers to clean even more.
Teacher's notes
Ciaran and his partner used the equipment in a logical sequence, starting with coarse filtering and finishing with the high quality filter paper, and cleaned the water significantly. He explained that he and his partner agreed on a filtration approach and decided together the order in which they would use the various filters.
Next steps
Work on water-borne diseases, including information research in which pupils act as ‘specialists’ on different infections, linking with work in geography and Personal, Social, Health and Economic Education (PSHEE).
Assessment summary
Ciaran uses abstract ideas about particles when describing water purification, linking technological applications to underpinning science. He uses appropriate forms of scientific language and is able to justify the use of particular items of equipment in their appropriate order.
