teacher notes

Links to other areas

Technology: look at different gardening tools and determine their intended purposes and the main features. Create own gardening tool for a specific purpose.

English: procedural writing

Maths: Graph experiment results

Teacher Notes re: Experimental development

To help develop an understanding of fair test I follow the following process:

1. Make it clear what we are actually trying to find out
We are trying to find out which soil sample holds the most water

2. Brainstorm a list of variables (things that can be changed)
Soil type, amount of water, placement of water, amount of soil, height from which water is dropped etc

3. Have students choose one of those variables around which to develop an experiment
In this case we will only be changing the type of soil we are using. In other cases students may have several options to choose from.

4. Students then list all the variables that will change and all the variables that will stay the same
Changing variables (There should only be one thing written in here)
Variables to stay the same

5. Students then develop a hypothesis from here. They will be using language and ideas that are relevant to them
Thicker soils will hold more water
Water will flow more easily through sandy soils
The browner the soil the more water it will hold

6. The experiments are then developed around these hypotheses stressing the need to maintain a fair test by only changing the one variable in the list.

Note: In some cases I have demonstrated an experiment that is totally unfair. You may perform this experiment where you have different amounts of soil and water, you drip water onto some soils and pour it onto others etc. whatever you do you make it obviously unfair and then discuss the problems associated with this before the students start developing their own experiments.

Assessment and evaluation
Work is evaluated according to criteria decided upon by the class as to what are the main features that need to be included in a procedural text. This is then used as a guide and a checklist to evaluate performance. What follows is an example of a list of features determined upon by the class before planning and presenting their experiments.

To successfully complete this task you need to include:

A list of equipment
Your hypothesis
Clearly numbered steps
Sentences starting with action verbs
Diagrams (where appropriate)
Your results – set out in a clear, easy to follow form
Conclusions – what did your experiment prove
An explanation of how you kept your test fair
An evaluation of your experiment. How successful was it? What might you change? Why?