Internal Assessment Research Design
This criterion assesses the extent to which the student effectively communicates the methodology (purpose and practice) used to address the research question.
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Command terms indicate the depth of treatment required to earn the different marks.
- State: Give a specific name, value or other brief answer without explanation or calculation.
- Outline: Give a brief account or summary.
- Describe: Give a detailed account.
- Explain: Give a detailed account including reasons or causes.
RESEARCH QUESTION CONTEXT
A research question with context should contain reference to the dependent (manipulated) and independent (responding) variables or two correlated variables, include a concise description of the system in which the research question is embedded, and include background theory of direct relevance.
Research Question
There should be a single sentence which clearly and specifically states the objective of the investigation. Make sure you select a research question that can be measured using the time, materials and techniques available to you at school! The research question must clearly identify the manipulated and responding variables of the investigation. If you are using any living organisms, or products from living organisms, such as seeds from a certain plant, give the most precise name you can and give the scientific name if possible (e.g. Phaseolus vulgaris for kidney beans).
Check list:
Description of the System
Write a paragraph or two explaining why the experiment is appropriate and relevant to the study of biology. How does it relate to what is being learned in class? What process or phenomenon will the experiment support?
Check list:
Theory of Direct Relevance
Although not required by the IB Organization, for many investigations it is appropriate for students to include a hypothesis. A hypothesis is like a prediction. It will often take the form of a proposed relationship between two or more variables that can be tested by experiment: “If X is done, then Y will occur.” Also provide an explanation for the hypothesis. This should be a brief discussion (paragraph form) about the theory or ‘why’ behind the hypothesis and prediction. Be sure the hypothesis is related directly to the research question and that the manipulated and responding variables for the experiment are clear.
Check list:
A research question with context should contain reference to the dependent (manipulated) and independent (responding) variables or two correlated variables, include a concise description of the system in which the research question is embedded, and include background theory of direct relevance.
Research Question
There should be a single sentence which clearly and specifically states the objective of the investigation. Make sure you select a research question that can be measured using the time, materials and techniques available to you at school! The research question must clearly identify the manipulated and responding variables of the investigation. If you are using any living organisms, or products from living organisms, such as seeds from a certain plant, give the most precise name you can and give the scientific name if possible (e.g. Phaseolus vulgaris for kidney beans).
Check list:
- The research question is clearly stated and precisely formulated at the beginning of the paper
- The research question is clearly biology in focus
- The research question includes clear and specific manipulated and responding variables or two correlated variables
- The research question includes the scientific name(s) of the organism Genus species), if relevant
Description of the System
Write a paragraph or two explaining why the experiment is appropriate and relevant to the study of biology. How does it relate to what is being learned in class? What process or phenomenon will the experiment support?
Check list:
- The need/importance/relevance of the research question is clear
- The appropriate/accurate/relevant background biology of the phenomena being investigated is described
- The context includes the scientific name of the organism (Genus species), if relevant
- The context includes appropriate/accurate/relevant information about the variables being investigated
- Citations relevant to the contextual information are provided
Theory of Direct Relevance
Although not required by the IB Organization, for many investigations it is appropriate for students to include a hypothesis. A hypothesis is like a prediction. It will often take the form of a proposed relationship between two or more variables that can be tested by experiment: “If X is done, then Y will occur.” Also provide an explanation for the hypothesis. This should be a brief discussion (paragraph form) about the theory or ‘why’ behind the hypothesis and prediction. Be sure the hypothesis is related directly to the research question and that the manipulated and responding variables for the experiment are clear.
Check list:
- The context includes a description of the known relationships/effects of the variables being investigated
- There is a scientifically accurate hypothesis predicting the relationship between the variables, if relevant
- Citations relevant to the contextual information are provided
METHODOLOGICAL CONSIDERATIONS
Methodological considerations include: 1) the selection of the methods for measuring the dependent and independent variables, 2) the selection of the databases or model and the sampling of data, 3) the decisions regarding the scope, quantity and quality of measurements (e.g. the range, interval or frequency of the independent variable, repetition and precision of measurements), 4) the identification of control variables and the choice of method of their control and 5) the recognition of any safety, ethical or environmental issues that needed to be taken into account.
Selection of Methods
Check list:
Collecting Relevant Data
“Control of variables” refers to the manipulation of the independent variable and the attempt to maintain the controlled variables at a constant value. students should write a paragraph in which they describe how the control of variables is achieved. If the control of variables is not practically possible, some effort should be made to monitor the variable(s). State an explicit procedure or method for how each variable will be controlled and monitored. (For example, if the temperature must remain constant, figure out how you will do this and state it. Perhaps you might use a water bath that is maintained at a certain temperature. Or perhaps the amount of light must remain constant. In this case, you might take light readings before and after the experiment).
Check list:
Collecting Sufficient Data
The procedure must allow collection of sufficient data. The planned investigation should anticipate the collection of sufficient data so that the aim or research question can be suitably addressed and an evaluation of the reliability of the data can be made. As a rule, the lower limit is five measurements, or a sample size of five. Very small samples run from 5 to 20, small samples run from 20 to 30, and big samples run from 30 upwards. Obviously, this will vary within the limits of the time available for an investigation.
The data range and amount of data in that range are also important. For example, when trying to determine the optimum pH of an enzyme, using a range of pH values between 6 and 8 would be insufficient. Using a range of values between 3 and 10 would be better, but would also be insufficient if only three different pH values were tested in that range.
Check list:
Safety, Ethics and Environmental Considerations
Describe any safety precautions that must be taken during the lab, including personal and environmental concerns.
Check list:
Methodological considerations include: 1) the selection of the methods for measuring the dependent and independent variables, 2) the selection of the databases or model and the sampling of data, 3) the decisions regarding the scope, quantity and quality of measurements (e.g. the range, interval or frequency of the independent variable, repetition and precision of measurements), 4) the identification of control variables and the choice of method of their control and 5) the recognition of any safety, ethical or environmental issues that needed to be taken into account.
Selection of Methods
Check list:
- The background information about the methodological approach is well described
- The methods for measuring the variables are justified, if relevant
- The selection of the database or model are justified, if relevant
Collecting Relevant Data
“Control of variables” refers to the manipulation of the independent variable and the attempt to maintain the controlled variables at a constant value. students should write a paragraph in which they describe how the control of variables is achieved. If the control of variables is not practically possible, some effort should be made to monitor the variable(s). State an explicit procedure or method for how each variable will be controlled and monitored. (For example, if the temperature must remain constant, figure out how you will do this and state it. Perhaps you might use a water bath that is maintained at a certain temperature. Or perhaps the amount of light must remain constant. In this case, you might take light readings before and after the experiment).
Check list:
- The manipulated variable(s) is correctly identified with units and levels
- There is justification for how the levels of the manipulated variable were were chosen, if relevant
- A quantifiable responding variable(s) is correctly identified with units
- There is justification for how the responding variable(s) was chosen
- The important/relevant control variables are identified, with the potential impact of each discussed
- There is justification/explanation for a positive and/or negative control group, if relevant
- There are sufficient validity measures to ensure the method measures what it is intended to measure
Collecting Sufficient Data
The procedure must allow collection of sufficient data. The planned investigation should anticipate the collection of sufficient data so that the aim or research question can be suitably addressed and an evaluation of the reliability of the data can be made. As a rule, the lower limit is five measurements, or a sample size of five. Very small samples run from 5 to 20, small samples run from 20 to 30, and big samples run from 30 upwards. Obviously, this will vary within the limits of the time available for an investigation.
The data range and amount of data in that range are also important. For example, when trying to determine the optimum pH of an enzyme, using a range of pH values between 6 and 8 would be insufficient. Using a range of values between 3 and 10 would be better, but would also be insufficient if only three different pH values were tested in that range.
Check list:
- The number and range of levels of the manipulated variable are suitable, if relevant
- The interval or frequency of measuring the responding variable is suitable, if relevant
- The sample size is appropriate for the investigation and allows for statistical analysis, if relevant
- The number of repeats of responding variable measurements are suitable to ensure reliability and allow for statistical analysis
- The precision of measurements of variables are suitable for the investigation and allow for statistical analysis
Safety, Ethics and Environmental Considerations
Describe any safety precautions that must be taken during the lab, including personal and environmental concerns.
Check list:
- The safety issues are fully considered, including safe handling of chemicals and equipment
- The reasonable consumption and use of chemicals/materials is addressed
- There is use of human consent forms, if relevant
- There is adherence to the IBO animal experimentation policy, if relevant
- The environmental impact of the investigation is fully considered (such as disposal of chemicals)
- There is description and justification of approaches used to minimize the impact of the investigation on field sites
DESCRIPTION OF METHODOLOGY
The description of the methodology refers to presenting sufficiently detailed information (such as specific materials used and precise procedural steps) while avoiding unnecessary or repetitive information, so that the reader may readily understand how the methodology was implemented and could in principle repeat the investigation.
Method for Collecting/Selecting Data
Consider making a list of materials needed. Be as specific as possible (example: “50 mL beaker instead of ‘beaker’, type of microscope with magnification range). A diagram or photograph of how the experiment is set up may be appropriate. Be sure the diagram includes a title and any necessary labels. You might have to decide how much of a substance or a solution to use. If so, state your reasoning or show the calculations.
Explain the method (procedure) that was used in the experiment. This can be in the form of a list of step-by-step directions or a narrative. Provide enough detail so that another person could repeat your work by reading the report! You don’t have to go into detail about standard, well-understood actions such as measuring a temperature with a thermometer, weighing out a substance, etc. If a standard technique is used, it should be referenced. For example, while planning an investigation to study the effect of light wavelength on the rate of photosynthesis in Cabomba, the student may have adapted a method to measure the rate of photosynthesis taken from a textbook. A standard reference would then be expected as a footnote, for example, “Freeland, PW (1985) Problems in Practical Advanced Level Biology, Hodder and Stoughton.” Or the student may adapt a general protocol provided by a teacher in a previous investigation. The reference may appear as: von Bargen, G (2017) “Studying the rate of photosynthesis” worksheet.
If something is done in the procedure to minimize an anticipated error, mention this as well. (Example: “Carefully cutting plant stem under water to reduce effect of air on transpiration rate.”)
In the method, clearly state how to collect data. What measuring device was used, what data was recorded and when? Or what qualitative observations were looked for (such as color change)?
If you are using a known experimental protocol, you must explain how you modified the standard method to make it your own.
Check list:
The description of the methodology refers to presenting sufficiently detailed information (such as specific materials used and precise procedural steps) while avoiding unnecessary or repetitive information, so that the reader may readily understand how the methodology was implemented and could in principle repeat the investigation.
Method for Collecting/Selecting Data
Consider making a list of materials needed. Be as specific as possible (example: “50 mL beaker instead of ‘beaker’, type of microscope with magnification range). A diagram or photograph of how the experiment is set up may be appropriate. Be sure the diagram includes a title and any necessary labels. You might have to decide how much of a substance or a solution to use. If so, state your reasoning or show the calculations.
Explain the method (procedure) that was used in the experiment. This can be in the form of a list of step-by-step directions or a narrative. Provide enough detail so that another person could repeat your work by reading the report! You don’t have to go into detail about standard, well-understood actions such as measuring a temperature with a thermometer, weighing out a substance, etc. If a standard technique is used, it should be referenced. For example, while planning an investigation to study the effect of light wavelength on the rate of photosynthesis in Cabomba, the student may have adapted a method to measure the rate of photosynthesis taken from a textbook. A standard reference would then be expected as a footnote, for example, “Freeland, PW (1985) Problems in Practical Advanced Level Biology, Hodder and Stoughton.” Or the student may adapt a general protocol provided by a teacher in a previous investigation. The reference may appear as: von Bargen, G (2017) “Studying the rate of photosynthesis” worksheet.
If something is done in the procedure to minimize an anticipated error, mention this as well. (Example: “Carefully cutting plant stem under water to reduce effect of air on transpiration rate.”)
In the method, clearly state how to collect data. What measuring device was used, what data was recorded and when? Or what qualitative observations were looked for (such as color change)?
If you are using a known experimental protocol, you must explain how you modified the standard method to make it your own.
Check list:
- There is a list or photograph of apparatus and materials used in the investigation; including size, graduation and uncertainty
- There is a clear description of preliminary trials, if completed
- The method used to change and measure the manipulated variable is full, clear and detailed (including tools, units and uncertainty)
- The method used to measuring the responding variable is is full, clear and detailed (including tools, units and uncertainty)
- The collection of data with other students or from outside sources is explained and referenced, if relevant
- The method used to maintaining and measuring controlled variables is full, clear and detailed (including tools, units and uncertainty)
- The is a detailed description of what measures were used to ensure experimental measurements are valid and consistent
- Citations relevant to the methodological information are provided
- There are captioned photographs of the investigation setup and data collection, which are references within the text
