Solving Scientific Problems: Depth Studies (HSC SSCE Biology): Revision Notes
Solving Scientific Problems: Depth Studies
What are depth studies?
Depth studies are your opportunity to work like real scientists by investigating questions, developing hypotheses, gathering evidence, and communicating your findings. Throughout your Biology course, you'll complete investigations that help you develop both scientific skills and deeper understanding of biological concepts.
When performing a depth study, you will pose questions about biological phenomena, develop hypotheses to answer these questions, and then seek evidence to support or challenge your ideas. This evidence might come from conducting your own experiments (primary data) or from researching what other scientists have already discovered (secondary data). You'll analyze data, often using mathematical or graphical representations, and communicate your findings to appropriate audiences.
The knowledge in biology can be organized into five major concepts: form and function; similarity and diversity; stability and change; systems and interactions; and patterns, order and organisms. Your depth studies will explore questions within these conceptual areas, helping you understand that biology is not simply a collection of isolated facts, but a connected web of ideas and relationships.
Types of depth studies
There are two broad categories of depth studies you can undertake:
First-hand investigations
First-hand or practical investigations involve designing and performing experiments to gather primary data or test claims. These investigations can take several forms:
- Laboratory work: Controlled experiments conducted in a school or research laboratory setting
- Field work: Observations and measurements made at home, school, or external locations such as excursions or community sites
- Model or device testing: Creating and evaluating physical models or biological devices
Secondary-source investigations
Secondary-source investigations involve researching and reviewing information and data collected by other people. These can include:
- Literature reviews: Analyzing and synthesizing existing research on a topic
- Emerging technology investigations: Exploring new technologies and their applications in biology
- Media analysis: Critically examining science fiction movies or novels for scientific accuracy
- Evidence-based arguments: Developing historical or theoretical accounts supported by research
Presentation formats
Your depth study findings can be presented in various formats:
- Written texts (experiment reports, field work reports, journal articles, essays, management plans)
- Visual presentations (diagrams, flow charts, keys, posters, portfolios)
- Multimedia presentations
- Physical models
- Combinations of the above formats
All depth studies involve analyzing data, whether primary or secondary. You'll look for patterns and trends by constructing and interpreting graphs, tables, flow charts, diagrams, keys, spreadsheets, and databases.
Why undertake depth studies?
Depth studies encourage you to identify areas of personal interest and deepen your understanding while taking responsibility for your own learning. Although your teacher may identify a field of study, you can pursue your own specific interests within that field, whether that's emerging technology, current research, profiles of working biologists, or other areas.
Depth studies provide you with valuable opportunities to:
- Use authentic research methods that scientists employ
- Analyze scientific works for relevance and validity
- Broaden your reading in fields that interest you
- Extend your depth of thinking and understanding
- Ask questions and investigate areas without definite answers
- Examine contentious issues using critical thinking skills
- Develop inquiry-based learning and creative thinking at your own level
The four stages of a depth study
The NSW Stage 6 Biology syllabus identifies four main stages for conducting depth studies, each involving specific Working Scientifically skills:
Stage 1: Initiating and planning
This stage involves:
- Questioning and predicting (BIO-1): Developing and evaluating questions and hypotheses for scientific investigation
- Planning investigations (BIO-2): Designing and evaluating investigations to obtain primary and secondary data and information
Stage 2: Implementation and recording
This stage involves:
- Conducting investigations (BIO-3): Collecting valid and reliable primary and secondary data and information
- Processing data and information (BIO-4): Selecting and processing appropriate qualitative and quantitative data using various media
Stage 3: Analysing and interpreting
This stage involves:
- Analysing data and information (BIO-5): Analyzing and evaluating primary and secondary data and information
- Problem solving (BIO-6): Solving scientific problems using data, critical thinking skills, and scientific processes
Stage 4: Communicating
This stage involves:
- Communicating (BIO-7): Communicating scientific understanding using suitable language and terminology for specific audiences or purposes
Posing questions and formulating hypotheses
Starting with brainstorming
The first step in any investigation is deciding on a question. A good research question is one that can be answered through experimentation, observation, or secondary-source investigation. Obviously, you should investigate something that genuinely interests you, and if working in a group, find something interesting to everyone.
Brainstorming is an excellent way to generate ideas. Write down as many ideas as possible without being critical at this stage. If working in a group, ensure everyone contributes and accept all ideas uncritically. Write everything down. After exhausting your ideas, evaluate them critically. Decide which questions are most interesting and which are actually possible to investigate given your time and available resources. Create a shortlist of questions, but keep your original long list as backup.
Developing research questions
A good research question should:
- Define the investigation clearly
- Set boundaries for the study
- Provide direction for the investigation
- Be specific enough to guide experimental design
- Identify what will be varied (independent variable)
- Identify what will be measured or observed (dependent variable)
Poor research question: "How can we make a seedling grow the best?"
This question is too vague because "best" is subjective and doesn't specify what will be measured.
Good research question: "Which one of two fertilizers gives the maximum growth of roots and stem in a seedling?"
This question is specific, identifies what will be varied (type of fertilizer) and what will be measured (root and stem growth).
Formulating hypotheses
Once you've refined your research question through background reading, you can formulate a hypothesis. A hypothesis is a predictive statement about the relationship between variables. It provides an expected answer to your research question based on existing models or theories.
Hypotheses are often written in "If...then..." format:
Structure: "If is introduced/increased/decreased, then will increase/decrease/stay the same."
Example: "If the amount of nitrogen in fertilizer provided to a seedling in the soil is increased, then the height of the stem and/or length of the roots of the seedling will increase."
Your hypothesis should:
- Make a testable prediction
- Be based on existing scientific models or theories
- Allow for quantitative testing (measurements)
- Identify both independent and dependent variables
Understanding variables
A good research question or hypothesis identifies the variables being investigated:
- Independent variable: The factor you deliberately change or manipulate in your investigation (e.g., type of fertilizer, amount of nitrogen)
- Dependent variable: The factor you measure or observe as a result of changing the independent variable (e.g., stem height, root length)
In depth studies, you should only change one variable at a time to establish clear cause-and-effect relationships. You may have multiple independent variables if time and resources allow, but test them separately.
Important considerations
If your experimental results agree with your hypothesis predictions, you can claim they support your hypothesis, increasing confidence in the underlying model. However, you cannot prove a hypothesis true—you can only disprove it or provide supporting evidence.
If results disagree with your hypothesis, you may have disproved it. This isn't failure! Many important scientific discoveries begin when hypotheses based on existing models are disproved, leading to new questions and deeper understanding.
Don't be surprised if your question or hypothesis changes during your investigation. In authentic scientific research, initial questions often lead to refined questions as understanding develops.
Conducting a literature review
What is a literature review?
A literature review is a search and evaluation of available literature in a particular subject area. It has a specific focus defined by your research question or hypothesis. If your depth study is a secondary-source investigation, the literature review may be the investigation itself.
A formal written literature review includes:
- Information you've found from various sources
- Complete references to all sources
- Interpretation and critique of what you've read
- Synthesis of different studies and viewpoints
A literature review is not merely a descriptive list of information or a summary of one source after another. It critically evaluates literature, expresses your perspective on strengths and weaknesses, brings together results from different studies, and identifies where researchers agree, disagree, and where significant questions remain.
Why are literature reviews important?
Literature reviews help you to:
- Increase your breadth of knowledge and identify what is and isn't known about a research area
- Learn from others' work and generate new ideas relevant to your project
- Identify gaps in current knowledge that you could research
- Identify methods relevant to your project, avoiding reinventing approaches or repeating others' mistakes
- Recognize the variety of views (sometimes opposing) in a research area and consider how these relate to your own views
Purpose in planning investigations
When planning an investigation, a literature review provides information about:
- Past findings and procedures
- Techniques and research designs already used
- Methods worth copying, methods needing modification, and methods to avoid
You may plan your investigation to target a research gap or replicate an investigation to test and validate claims.
How to write a literature review
The length and detail of your literature review depends on its purpose. If it's a depth study itself, it will be more detailed and draw conclusions about research. If it's used as an introduction to inform your research, it will be shorter and more focused. Discuss expectations with your teacher.
Step 1: Getting started
- Define your topic or research questions (key concepts)
- Formulate a literature review question (you may need to do preliminary reading first)
- Create a list of keywords for searching
Step 2: Finding articles
- Use library catalogues, databases, and the Internet
- Refine your search technique using specific words that narrow your search to the focus question
- Interpret and evaluate your search results
- Record successful search terms
- Modify your search strategy as needed
Step 3: Structure and write
Your literature review should have three main sections:
Introduction
- Define the topic
- Establish your reasons for reviewing the literature
- State the specific focus of the review
- Explain the organization or sequence of your review
Body
- Group the literature according to common themes
- Explain the relationship between your research question and the literature reviewed
- Proceed from general, wider views to the specific area you're targeting
- Include information about the usefulness, recency, and major authors or sources
- Discuss where researchers agree and disagree
- Evaluate strengths and weaknesses of different studies
Conclusion
- Summarize important contributions of the literature
- Point out important flaws or gaps in research
- Explain the link between your focus question and the literature reviewed (if the literature review is your depth study)
- Explain why you've chosen your investigation area (if the literature review was conducted to refine your investigation)
Evaluating sources
Always critically evaluate what you read. Be wary of pseudoscience and material that hasn't been peer reviewed.
The CRAAP test
Apply the CRAAP test to evaluate sources, especially websites:
- Currency: How recent is the information? Has it been updated?
- Relevance: Does it relate to your research question? Is it at an appropriate level?
- Authority: Who is the author? What are their qualifications? Is it peer-reviewed?
- Accuracy: Is the information supported by evidence? Can you verify it elsewhere?
- Purpose: Why was this information created? Is there bias?
The most reliable sources are:
- Educational institutions (particularly universities)
- Government and scientific organizations (e.g., CSIRO, WHO)
- Professional journals (e.g., Medical Journal of Australia)
- Peer-reviewed academic publications
Search tip: Narrow your search to particular types of sites by including site.edu or site.gov in your search terms to find only educational or government sources.
Recording your research
Keep detailed records of the information you find and all sources so you can correctly reference them later. Start a logbook (hard copy or electronic) at this early stage. You can write references directly in your logbook or attach printouts. This will save significant time later in your investigation.
Key Points to Remember:
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Depth studies are opportunities to work scientifically and solve real biological problems by posing questions, developing hypotheses, gathering evidence, and communicating findings.
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There are two main types: first-hand investigations (gathering primary data through experiments, field work, or models) and secondary-source investigations (analyzing existing research and data).
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The four stages of a depth study are: initiating and planning, implementation and recording, analysing and interpreting, and communicating.
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Good research questions are specific, testable, and identify both independent and dependent variables. Hypotheses are predictive statements about variable relationships, often written as "If...then..." statements.
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Literature reviews help refine questions, identify knowledge gaps, evaluate research methods, and understand different viewpoints. Use the CRAAP test (Currency, Relevance, Authority, Accuracy, Purpose) to evaluate source quality, particularly for websites.