Unit 2 - Area of Study 3: Student-directed practical investigation
Design and undertake a practical investigation related to external influences on behaviour and draw conclusions based on evidence from collected data.
Examples of learning activities
How does sight affect perception of flavour?
The practical investigation builds on knowledge and skills developed in Unit 2 Area of Study 1 and/or Area of Study 2. Teachers must consider the management logistics of the investigation, taking into account number of students, available resources and student interest. The following questions require consideration:
- How much input will students have into the selection of the research question?
- To what extent will all students consider individual research questions, the same investigation question, or complete different parts to the same question so that class data can be pooled?
- How much input will students have into the selection of the type of investigation undertaken (laboratory work, literature review, observational studies, surveys or different combinations of investigation techniques)?
- How much input will students have into the design of the investigation?
- Is class data pooling a possibility?
Teachers could provide students with a template that structures the investigation into a series of timed phases. Students may subsequently adapt the template as a personal work plan in their logbooks.
Topic selection phase
In this detailed example, the investigation question was generated during a class discussion of the relationship between vision and taste, following a set of investigations undertaken in relation to visual distortions of perception and the location of taste receptors on the tongue. One student commented on a particular type of jelly bean that was yellow in colour but had a blueberry taste. Other students in the class reflected on further examples where the foods they ate had a different taste from what they had expected. A further student comment related to television commercial advertisements promoting a novel food product by showing ‘blindfold’ comparisons of the ‘new’ food versus the ‘old’ food.
From this discussion, students developed a number of research hypotheses for investigation. It was determined that each group would test their research hypotheses on children from different year levels at the local primary school. Students selected research hypotheses of interest and worked in groups to perform their selected investigations.
Sample hypotheses included:
- If taste perception is directly associated with visual cues, then the children in a Level 2 class who are given pink-coloured milk are more likely to describe it as being ‘strawberry’ flavoured than the children in a Level 2 class who are given yellow-coloured milk.
- If taste perception is directly associated with visual cues, then the children in a Level 3 class who are given milk that is flavoured with apple flavouring, with no colour change, are more likely to describe the flavour as ‘plain’ when asked to describe its taste.
- If taste perception is directly associated with visual cues, then the children in a Level 4 class who have not been blindfolded will be able to identify samples of fruit (apple, pear, orange, mandarin, strawberry and blueberry) more accurately than the children in a Level 4 class who were blindfolded.
- If sweetness is directly associated with visual cues, then the children in a Level 5 class who are given different samples of milk that vary in colour from cream to white are more likely to describe the creamier coloured milks as ‘sweet’ when compared with the whiter coloured milk samples.
Students may need guidance in:
- identifying the independent, dependent and controlled variables in the experiment, and operationalising variables
- ensuring that resources are available that meet the requirements of the investigation
- the use of deception in psychological investigations
- fitting the investigation into the time available, and developing a work plan.
Teachers should work with students to:
- evaluate and refine proposed hypotheses
- develop consent forms for the investigation
- identify safety aspects of undertaking experiments related to taste, particularly with respect to identification of possible food sensitivities and allergic reactions, and hygienic handling practices of the food being tested
- determine audience for final report presentation and report format.
Prior to students undertaking practical investigations, the teacher must approve student-designed methodologies. A possible general methodology for the experiment is as follows:
- Contact made with primary school to arrange consent forms to be completed and collected, and confirm times and venues for investigations.
- Students plan how the experiment will be carried out to ensure that possible confounding variables have been controlled.
- Students determine materials required, including quantities.
- Students set up a data-recording sheet.
- Students perform investigations, record and analyse results and prepare final presentation of report to a selected audience.
Students consider the data collected, report on any errors or problems encountered, and use evidence to explain and answer the investigation question. Other avenues for further investigation may be developed following evaluation of their experimental design and feedback from investigation participants.
The above phases could be recorded in the student logbook. The report of the investigation can take various forms including a written report, a scientific poster or an oral presentation of the investigation.