Scientific Investigations

Students learn that the experimental method is a dynamic process influenced by initial observations, new evidence, unexpected results or phenomena arising from the investigation. They examine the interrelated roles of practical and secondary-sourced investigations. When conducting practical and secondary-sourced investigations, students use peer feedback to refine their investigative designs and report on their findings.

Students explore the importance of accuracy, validity and reliability in relation to the investigative work of a scientist. They examine the differences between a scientific investigation and a scientific report, recognising that although the report format follows a sequential order, the investigation need not.

Investigating Science Stage 6 Syllabus p.49


Practical Investigations to Obtain Primary Data

WHAT initiates an investigation?


research the factors that led scientists to investigate the following, including but not limited to:
– peptic ulcers (Marshall and Warren)
– plant growth (Von Helmont)
– microwaves (Spencer)

Click on the image to go to the Press Release

Click on the image to go to the Press Release


propose a reason for the scientists undertaking their investigations above by examining the type of data or information that they sought, for example:

– finding relationships or patterns in identified phenomena
– testing the conclusion of a previous investigation
– utilising scientific knowledge and understanding to make more accurate predictions and develop new technologies


determine the hypotheses that were tested in each of the scientific investigations above


describe where deviations from the traditional and linear models of scientific methodology were necessary in order to test each hypothesis in the investigations above


Different Types of Scientific Investigations

WHAT Type of methodology best suits a scientific investigation?


using examples, evaluate the objectives and data collected in an investigation by a recognised scientist or team of scientists, including but not limited to:

– Marshall and Warren and peptic ulcers
– Eratosthenes and Earth’s circumference
– Doppler and the Doppler effect
– Priestley’s experiments with oxygen


evaluate the methodology of the scientific investigations above by:

– justifying the method chosen based on the subject of the investigation and the context, for example: experimental testing, fieldwork, locating and using information sources, conducting surveys and using modelling and simulations

– evaluating the relevance of the investigation by considering the peer-reviewed literature in the area of study

– justifying the suitability of the type of data that is to be collected


Student Investigation


● develop a method most appropriate to test a hypothesis following observation

● justify the type of methodology used to test the hypothesis


Reliability and Validity

how is the integrity of a scientific investigation judged?


evaluate the design of the student investigation by:

– explaining the choice of independent, dependent and controlled variables with reference to the research question

– explaining the sample selection and sample sizes used for gathering data

– justifying the suitability of materials used based on their relevance to the research question, availability, cost, risk and familiarity of use

– assessing the ethics of conducting the investigation by considering confidentiality, humane treatment and animal welfare

– predicting an achievable time frame to conduct the investigation

– justifying working individually or collaboratively


conduct the planned investigation and collect, record and analyse primary data


draw a conclusion or conclusions, and suggest further investigation or research by:

– analysing the results and interpreting the data

– explaining the relevance of the findings of the investigation in relation to the inquiry question and hypothesis

– justifying the methodology and any changes made to improve the data collected

– describing potential beneficial and harmful consequences when the findings are applied to a real-world scenario


evaluate the validity of the investigation by determining whether the tests measured what they were intended to measure


evaluate the reliability of the investigation by determining:

– consistency of the results obtained

– measures taken to reduce error



what is the structure of an investigative report?


review a published and peer-reviewed scientific report to determine the conventions of writing a report on a practical investigation


use a sample of a published and peer-reviewed secondary source to identify:

– the purpose of the report

– measures taken to reduce error

– the language style used

– the presentation and structure of the report


compare and contrast the structures and functions of a scientific investigation and its written report


prepare a report on the student investigation that was carried out

Randomistas (online).jpg

Randomistas - Randomised trials

"We may not be aware of it but many of us have been taking part in so-called randomised tests.

They're carried out on us every day by political parties, supermarkets and search engines to improve existing services and create new ones.

And throughout history, randomised tests have been used in many endeavours from finding the cure to scurvy to discovering what policies improve literacy rates."

Source: 'Randomistas: How Radical Researchers Changed Our World' RN Breakfast Tuesday 6 March 2018 8:13AM


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