Paper instructions:
Extended Experimental Investigation
Rationale:
Micro-organisms are vital to humans and the environment, but some are harmful to us. These are commonly referred to as germs. “Germ” is a catch-all term for these invisible organisms, mainly bacteria, fungi and viruses, which cause disease. Germs in the home can show up where you least expect them, despite good efforts by most to keep their homes germ free, over 65% of colds, 50% of all cases of diarrhea and 50% – 80% of food-borne illnesses are caught in the home, and common household items are often to blame.
Research/Focus Question:
Task Summary:
Your task is to carry out a long term experiment of your own design to investigate one of the following:
• the cost effectiveness of a cleaning or disinfecting product on the destruction of microbes commonly present in our environment
• the control of a unicellular or invertebrate organism that is of concern to public health
• the nature of the surface on population density and types of organism present.
• the effect of storage/preservation conditions on the growth of unicellular organism that is of concern to public health.
The focus is on planning and problem solving using primary data generated through experimentation by the student.
- a planned course of action
- a clearly stated research question giving a purpose and aim to the investigation
- descriptions of the experiment showing evidence of modification or student design
- evidence of primary and secondary data collection and selection
- the execution of the experiment/s
- data analysis and discussion
- evaluation and conclusion/s with justification
- the presentation of the discussion and findings.
Length:
Approximately 1500 words 2000 words where depth of topic warrants
Materials:
JOURNAL [complete as the investigation proceeds]
1. Do research to find what science says about :
a) factors that affect the ………… and why each has the effect it does. (Refer to theory that relates to the concepts that explain the factors that affect …………
b) the effect of your variable and how science explains its effect. Make initial notes here. Include diagrams as needed and record sources below.
Bibliographic details:
Author Year Title Other details (resource type)
2. Which option will you investigate?
3. Write an AIM for the investigation :
4. What hazards are there in this experiment and what will be done to minimise them?
5. Which specific factor do you wish to investigate? (This will be your manipulated variable)
• Which variable/s are you going to measure (your dependent variable)?
6. What is your hypothesis about how your factor will affect the ………… as it is changed in a specific way (describe)?
7. Which variable/s are you gong to keep the same to make the test fair (your controlled variables)? For each, describe exactly how you will control it. (maximum of 5 variables)
i) It needs to be controlled because It will be controlled by
ii) It needs to be controlled because It will be controlled by
iii) It needs to be controlled because It will be controlled by
iv) It needs to be controlled because It will be controlled by
6. You will gather data for 3 –4 different conditions and repeat the experiment.
Design a table that will contain
• the results for 3 – 4 trials for your variable
• a place for the calculation of average measured result for each value
9. Plan the order of actions that you will do; paying particular attention as to when and how you will make measurements in the sequence of steps METHOD
Perform the experiment and enter the data in the table above
10. Make inferences from your results. What do your results tell you? Is there a major relationship, pattern or trend in your results? If, so describe it.
11. What did you find out about your hypothesis? Was it supported, unsupported or were the results unclear and inconclusive?
12. What difficulties or doubts about the results did you have in doing this investigation? (Look at the variation in the results to consider the precision achieved, were any unexpected?)
13. Explain how you could improve each of the following and justify why
a) design of the investigation
b) the method that was used
c) the reliability of the results