IB Biology, Chemistry & Physics IA: The 4 Criteria + Research Question

The science IA and its four criteria. This answer is wrong.

The student thought data analysis was the biggest part. Can you see the mistake?

Your IA is out of twenty-four. Four criteria, six marks each. Twenty-four divided by four is six.

That's one mark of this six-mark IA quiz. Five more, and each one hides a trap like that.

So what are the four criteria? And which two of them carry half of your marks?

It's the same four criteria in Biology, Chemistry and Physics, at S-L and at H-L. First, research design. Your question, and the method you use to answer it. For the top band, your method has to be so clear that someone else could repeat it.

Second, data analysis. How you record your results and process them, with their uncertainties. Clear tables, the right units, and a graph that answers your question. Third, conclusion. What your data actually says, compared with the science you know. It has to come from your data, not from what you hoped to find.

Fourth, evaluation. The weaknesses of your method, how much each one affected your results, and realistic ways you'd fix them. Those are the four. That's mark two.

So, conclusion and evaluation together. How many marks out of twenty-four? Six, twelve, or eighteen?

Twelve. Half of your IA is about explaining your results and their weaknesses. Mark three. So you need a topic with results you can actually explain. And it starts with one sentence: your research question.

Here's a question a student wrote. How does temperature affect enzymes? It sounds fine, right? But it's far too broad. Which enzyme? Which temperatures? And what do you measure?

A focused question names three things. What you change: that's the independent variable. What you measure: that's the dependent variable. And where: the system you're studying.

So you write it like this. How does temperature, from twenty to sixty degrees, affect the rate of oxygen production by catalase from potato? Now anyone could repeat your experiment. Mark four.

So in that question, what is the dependent variable? Temperature, catalase, or the rate of oxygen production?

The rate of oxygen production. It's what you measure. Temperature is what you change, so it's the independent variable. Catalase from potato is the system. Mark five. Now, could you spot a weak question in someone else's IA?

You're the teacher now. Three research questions. Give one tick for what changes, one for what's measured, and one for the system.

Question A says light, but how much? It measures photosynthesis, but how? In which plant? Zero ticks. Question B has the lamp distances and the pondweed, but you can't read photosynthesis off a ruler. Two ticks. Question C counts oxygen bubbles per minute. Three ticks.

So test every question you write with three words. Change. Measure. Where. But can you actually finish that question in the time you get?

The I-B suggests about ten hours for the whole IA. That includes planning, collecting data and getting feedback from your teacher. And your report is three thousand words at most. Mark six.

So a topic that needs a whole season of plant growth is a trap. Ask yourself: can I collect enough data in my lab time? Your teacher may have their own deadlines, so check with them.

So where do good topics come from? A practical you've already done, and wanted to push further. A part of the syllabus you actually liked. And it doesn't have to be a lab experiment. A database or a simulation can work too, if your teacher agrees. Whatever you pick, it still needs a focused question.

Now a chemistry one. Does temperature affect reaction rate? Use your three words. Pause if you want to try it first; here it is.

Change: the temperature, from twenty to sixty degrees. Measure: the time for the mixture to turn cloudy. Where: sodium thiosulfate with hydrochloric acid. Same three words, a different science.

Marks per criterion? Six. Half the marks? Conclusion and evaluation. A focused question? Change, measure, where.

You have a focused question. So which variables do you keep the same, and how many repeats do you need? That's part two.