IA guide

Over the course of this two-year course, HL students will complete at least 60 hours of labs and SL students will complete at least 40 hours of labs. Most of these will not be graded, but be designed to give you meaningful experience that will either support material learned in class or prepare you for a future in science.

You will be graded on a single Internal Investigation worth 20% of your final Biology mark. This is the only part of your final grade that you can be sure of before you begin your final exams in May. As such, it is worth working hard to make this a strong foundation for the rest of your grades.

NOTE: DO NOT LOOK AT A LAB TO SIMILAR TO YOUR OWN WHILE WRITING. EVERY LAB BELOW IS IN TURNITIN. PLAGIARISM CAUGHT BY THE IB WILL RESULT IN YOUR AUTOMATIC FAILURE OF THE DP.
Sample Lab Format
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Structure of your II

In many ways, the II is a cross between a traditional lab report and an extended essay. As such, you will need to include all the major parts of a lab, coupled with justification of your steps.
Find below a possible outline for a science EE:
  • Introduction
    • Why did you choose this topic?
    • What is your research question?
    • Why is this topic relevant? Any relevant news articles or sources saying this?
  • Background
    • Explain the science of your question.
    • What other research has been done on this topic? What was found? What is left unanswered by this research?
  • Investigation / Justification of Method
    • Based on the research found, what procedure have you chosen?
    • How did you change the procedure to make it your own?
    • What are your expected results?
      • State your hypothesis
  • Procedure
    • Variables in a table
      • IV, DV and CV described in a table
    • Equipment
      • All equipment listed with bullet-points (quantity and uncertainty)
    • Method
      • Numbered steps of the method, including all variables, equipment and statistical tests used
  • Results
    • Summary of qualitative observations
      • Full observations in the appendices
    • Processed data table
      • Full raw data and sample equations in appendices
    • Graphs of processed data
    • Statistical test summary
      • With decision rules and results
      • Full sample calculations in appendices
  • Discussion
    • Results
      • Summarize your results in writing. Use statistical test results to help draw conclusions.
      • Explain your results scientifically. Why were some conditions better than others? Support this with research.
      • Do your results agree with your hypothesis? Explain.
      • How do your results compare with those you found in your research (see background)? Explain.
    • Evaluation
      • What were the possible sources of error in your lab and how could they have affected your results?
      • Are your results still valid? Explain.
  • Conclusion
    • What do your results mean for world? Do they have any significant impacts? Any relevant news articles?
    • What are future labs that might make a good extension to your research.
  • Works cited
  • Appendices

Notes on the Design of the experiment in your IA

For this section, you will need to independently designed experiment, paying close attention to detail. In particular, you will need to include the following parts:
  • Research question - Include your IV and DV in the question, with units in brackets.
  • Hypothesis - Include your IV and DV in the hypothesis, as well as a scientific explanation for your expected results using graphs and research (with citations) where appropriate.
  • Variables - Should be presented in a table. You need to choose your IV and DV, and include their units, uncertainties and how they will be measured (equipment or procedural summary). You should also include all relevant CVs with units and uncertainties, along will an explanation of how the variable could affect your results and how this will be controlled or monitored.
  • Equipment/Materials - A bullet pointed list of all the equipment you will use, including their size and brand, and how many/much will be needed. Where relevant, you can also include their uncertainties. Plants or animals should include their binomial species name.
  • Procedure - Should be presented as numbered steps, and include a labelled diagram if useful. It should include how all your variables will be measured or controlled, including all the equipment used. Every CV should be controlled in the Variables and Procedure sections. Your procedure should allow the collection of sufficient, relevant data. In my class, this means that you should have an IV increments of at least 5, and repeat your procedure for 5 full trials. At the end of your procedure, you should include any statistical tests you plan on using (explain why) and address any ethical concerns if needed.

As a teacher, the IB states that students should not be:
  • given a focused research question
  • told the outcome of the investigation
  • told which independent variable to select
  • told which variables to hold constant
  • which apparatus to select
  • the experimental method
  • how to collect the data
  • how much data to collect.

Notes on Data Collection and Processing

For this criterion, you will need to independently collect and organize raw data, process it correctly and present it. In particular, you will need to include the following parts:
  • Qualitative Raw Data - Include observational data of things you have seen, smelled, heard et cetera.
  • Quantitative Raw Data - In a table, organize and present your numerical data from measuring your IV. This should include all units and uncertainties in the headings, with consistent decimal places of equal precision. Tables should have titles including the relevant variables and their units.
  • Data processing - Include sample calculations of all your data processing, along with a brief explanation of why you are manipulating the data this way. Make sure that you do whatever calculations are necessary to determine your DV here. At a minimum, you should calculate a mean and standard deviation, with any relevant statistical tests.  See the DP Biology Statistics in Labs guide for more options.
  • Processed data - Separately from all raw data, present your processed data with appropriate units and uncertainties in the headings, with consistent decimal places and equal precision. Tables should have titles including the relevant variables and their units.
  • Graph - Choose the appropriate graph to present your processed data (never your raw data), including a title and axes labels (the variables and their units with uncertainties). Your graph should also include correct error bars (usually based on your standard deviations) and a line of best fit, where applicable. 

As a teacher, the IB states that students should not be told:
  • how to record their data
  • what data to record
  • how to process the data
  • what quantities to graph/plot
  • how to present the data.

Notes on the Conclusion and Evaluation

For this criterion, you will need to use your raw and processed data, along with the results of relevant statistic tests, to draw conclusions based on cited research. You will then need to evaluate your procedure to find significant errors, then suggest realistic improvements to them. In particular, you will need to include the following parts:
  • Results​ - In a written format, restate your research question and discuss whether or not your data supports your original hypothesis. Make sure to use actual data (both qualitative and quantitative) and the results of your statistical tests to do so, and refer to your graph as necessary when describing any patterns or relationships. Scientifically explain the results you got, with justification, and compare them to published scientific literature when possible.

  • Evaluation - In a paragraph or two, discuss the reliability of your data, making reference to your choice of IV increments, standard deviation and variability of data. You may also talk about your statistical tests. Some mentions of errors may also be appropriate here, as long as they are mentioned again in the Evaluation section. Make sure to discuss any strange data points. Finally, where applicable, suggest further extensions to your experiment that could be done in the future.
    In a table, outline all important errors, stating what type they are (systematic, human or random) and describe how they may have affected your results. These should be mainly systematic errors, with human errors kept to a minimum. 
    In the same table, suggest realistic improvements for every error. Make sure to be specific in describing and explaining how these errors will be addressed, citing research where needed.
    ​
  • Conclusion - In a closing paragraph, describe the implications of your results on the world. Discuss any impact your research may have, and suggest future experiments that might make a good extension to your work.

Ethical considerations

When doing experiments on any animal (including humans), it is imperative that they are well treated and never exposed to undue stress or discomfort. Below, I will quote and expound upon the IB Animal Experimentation Policy, adding bolding for emphasis.
  • Any planned and actual experimentation involving animals must be subject to approval following a discussion between teacher and student(s) based on the IB animal experimentation policy.
As you design any experiment involving animals, you need to come speak to me to ensure that it is acceptable.
  • Experiments involving animals must be based on observing and measuring aspects of natural animal behaviour. Any experimentation should not result in any pain or undue stress on any animal (vertebrate or invertebrate) or compromise its health in any way.  Therefore experiments that administer drugs or medicines or manipulate the environment or diet beyond that easily tolerated by the animal are unacceptable. Experiments resulting in the death of any animal are unacceptable.
When designing your experiment, you must research the normal conditions of your animal's environment (temperature, humidity, diet, sleep periods, et cetera). You may not ever exceed these conditions as this would naturally discomfort or possible harm the animal.
  • Any experimentation involving humans must be with their written permission and must follow the above guidelines. Experiments involving body fluids must not be performed due to the risk of the transmission of blood-borne pathogens.

You may not design any experiment involving humans without preparing a consent form wherein you explain your procedure and aims, as well as how you will use the data. This way, you can obtain their informed consent. Any participant should also be allowed to leave the experiment at any time.
Furthermore, you may not design any experiments involving body fluids, such as blood, urine, tears or sweat. For example, this means that any conditions or exercise that could cause perspiration are not allowed.

Find the full details straight from the IB at the following web site:

Examples