SILO 2.3 (DRAFT)

Year 2, Term 3: Fair tests

Focus: Variables Scope and sequence: Variables, Fair tests

Learning intention: Students identify questions of interest and define variables to guide their investigations and presentations of relevant data.

NSW Syllabus
Australian Curriculum (version 9.0)
"A student gathers and organises data, displays data in lists, tables and picture graphs." (MA1-DATA-01)
"Students learn to acquire data for categorical variables through surveys, observation, experiment and using digital tools; sort data into relevant categories and display data using lists and tables." (AC9M2ST01)


Introduction to the topic

This video (3:41) is a good introduction to the three main types of variables, namely:

Independent variable: The thing you change

Dependent variable: The thing you measure

Control variables: The things that stay the same.



 

Fair tests

Cows Moo Softly


http://downunderteacher.blogspot.com/2012/01/freebie-science-variables-and-job-roles.html

Independent variables 

In science experiments, the independent variable is the thing that you change.

Dependent variables

In science experiments, the dependent variable is the thing that you measure.

Control variables

In science experiments, the control variables are the things that remain the same.


More on fair tests

This video (3:45) has a good example of a fair test using some common kitchen ingredients such as baking soda and three different types of vinegar.




Projectile activity

The following activity involves air rockets but it would be more precise to call these 'rockets' projectiles. This is because there is no fuel to keep the rocket moving after the initial launch force provided by your foot pushing down on the air as shown in the short video (0:08) below.


The image below shows that 45 degrees should give you the longest distance.


(Source: https://stickmanphysics.com/stickman-physics-home/two-dimensional-motion/projectile-motion/ © https://stickmanphysics.com/)

The projectile below is set to launch at 40 degrees.


Activity steps:



  • Was this a fair test?

  • Why/why not?


  • Which elements of the air rocket activity fit the criteria for fair tests?

  • Which elements cannot be easily controlled?


Reflex activity

This activity can be done in pairs using a ruler, paper and a pencil.


Correlation across data sets

Sometimes there might seem to be correlations across data sets which are best described as coincidences such as in the following example:


By Tyler Vigen, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=48043945

 


 

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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