What our activity was:
Two tests, the first comparing one cold soda and one warm soda (one either sprite or 7up), the second comparing one flat soda and one carbonated soda. We had the kids taste and then choose which they preferred, discuss why, and then if they thought it was fair test, and why or why not. The table below shows their choices for the two tests and their initial reactions on fairness before any discussion.
What some of the kids said:
|Test 1||Test 2|
|Lyric||A – not fair, one pop was flatter||A – not fair, one pop was flatter|
|Shania||B – not fair, taste flatter||A – not fair b/c 1 was flat|
|Anastasia||B – not fair, temperatures were different||A – B is not carbonated, not fair b/c flavor was taken from B|
|Test 1||Test 2|
|Hannah||B – colder, more flavor, tangy, not fair b/c 1 warm, 1 cold||A – B tastes like water, fair b/c both cold|
|Jhade||B – not fair, 1 warm, 1 cold||A – fizz, fair b/c both cold|
|Aslan||B – Its colder||A – not fair|
|Demari||B – colder, fair because you don’t know which soda is which||A – fair because temp was the same and you couldn’t tell which soda it was|
|Test 1||Test 2|
|Hadaree||B – sweeter, not fair||A – B tastes like H2O, not fair 1 was flat|
|Liam||B – tastes limeyer, not fair b/c 1 cold, 1 warm||A – B is flat, not fair|
|Jiren||B – colder, not fair b/c 1 cold, 1 hot||A – not fair b/c 1 was flat, but they were cold|
|Miss Leo||B – colder, not fair, 1 warm, 1 cold||A – not fair, 1 flat, 1 carbonated|
Liam- It’s unfair because one was cold and one was warm. Make it fair by making both of them cold. (Test 1)
What this tells us about the students’ prior knowledge:
As we can see from the comments documented above, overall, the students had a basic understanding of fair testing. They were able to notice that variables such as temperature and carbonation could not differ within the same experiment if we are testing between 2 different sodas (this would create too many variables in one test). A few students thought that once the first variable (coldness) was “fixed” in the second test, it made the second test fair. It took some discussion with their fellow campers and us to decide that maybe the second test was also unfair. The students’ ability to identify variables that differed between the two cups of soda led to further discussion on what should be changed to make the test ‘fairer’, and we elaborated on what exactly constitutes a fair test.
Demari at first thought that the tests were fair. After continuing to provoke critical thinking via inquiry on the idea of fair tests and engaging the students in discussion with their peers and our group members, Demari changed his mind and concluded that these tests actually were not fair.
One group (Anastasia, Shania, Lyric) got as far as discussing what role opinion plays in fair testing. Being that this entire experiment was based on opinion for a preferred taste, the entire experiment was an expansion of an unfair test. We came close to concluding what types of tests may be appropriate in science, specifically using measurable (quantitative) data. The term “fact” arose a few times, but we did not get a chance to elaborate. Shania even made a statement along the lines of everyone has a different opinion, so we cannot use opinions in such tests.
Some students approached the testing with a bias toward one soda (particularly Anastasia and Shania debated over their preferences). They were determined that they would be able to figure out which soda was which, and they would be able to tell which soda was their favorite by taste. However, when they experienced the flat and warm sodas, they immediately chose the sodas that were closest to their cold, carbonated, crisp drinking states.
Most students had some idea that in a fair test, there should only be one changing variable (though only one group I believe mentioned that specific word.) If some didn’t voice that thought at first (some did say that a test was fair at first because you could not tell which soda was which because we re-labelled them), after hearing the other kids talking about why they thought it was unfair, they agreed with the other students. It should be fairly simple to help them see how taking samples at the beach is related to the soda testing- that there should only be one variable changing.
What we can do with this knowledge at camp:
After discussing with students what they might be interesting in testing for the beach project, we can ask students what variables might play a critical role in influencing the prevalence/quantity/state of this component. For example, we can refer to the fair test experiment at Horizons to explain why testing on different days, at different time of day, etc. might affect the temperature or other measurable variables of the water, and in turn, why this might affect our data collection and analysis.