IB Internal Assessment (IA) Topic Ideas by Subject

The Internal Assessment (IA) is one of the most important components of your IB Diploma. Worth 20–25% of your final grade in most subjects, the IA gives you a chance to explore a topic you’re genuinely interested in — and demonstrate independent research skills that universities love.

But choosing the right topic? That’s where most students struggle. You need something specific enough to investigate thoroughly, yet broad enough to find data and draw meaningful conclusions.

In this guide, we share 60+ IA topic ideas across six popular IB subjects, along with expert tips for selecting a topic that sets you up for success.

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How to Choose a Great IA Topic

Before diving into specific ideas, here are the golden rules for picking an IA topic:

1. Pick Something You’re Genuinely Interested In

You’ll spend 10–20 hours on your IA. If the topic bores you, the quality of your work will suffer. Choose something that makes you curious.

2. Make It Specific and Focused

A common mistake is choosing a topic that’s too broad. “The effect of temperature on enzyme activity” is better than “enzymes.” Narrow it down to a single, testable research question.

3. Ensure Data Is Accessible

Whether you’re collecting primary data through experiments or using secondary data from databases, make sure you can actually get the information you need.

4. Check the Assessment Criteria

Each subject has specific IA criteria. Read them before committing to a topic. Your IA needs to demonstrate the skills being assessed — personal engagement, exploration, analysis, evaluation, and communication.

5. Discuss With Your Teacher Early

Your teacher can tell you if a topic is too ambitious, too simple, or has been done too many times. Get their feedback before you invest significant time.

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Physics IA Topic Ideas

The IB Physics IA requires an experimental investigation. You need to collect data, analyse it, and draw conclusions. Here are 10 ideas to spark your thinking:

1. How does the length of a pendulum affect its period? — A classic investigation that allows for precise measurements and mathematical modelling using the relationship T = 2π√(L/g).

2. Investigating the relationship between voltage and current in different resistors — Test Ohm’s Law with various materials and temperatures to explore resistance behaviour.

3. How does the angle of incidence affect the intensity of reflected light? — Use a light sensor and mirror to investigate reflection and verify the law of reflection quantitatively.

4. The effect of mass on the terminal velocity of coffee filters — Drop stacked coffee filters and use video analysis to determine terminal velocity, exploring drag force relationships.

5. How does string tension affect the frequency of a standing wave? — Use a vibration generator and string to investigate the relationship between tension, frequency, and wavelength.

6. Investigating the efficiency of a solar cell at different angles of illumination — Measure power output at various angles to determine optimal positioning.

7. How does the diameter of a wire affect its electrical resistance? — Systematically test wires of the same material but different diameters to verify the resistivity equation.

8. The effect of water depth on the speed of water waves — Create waves in a ripple tank at different depths and measure wave speed to explore shallow-water wave behaviour.

9. Investigating the relationship between spring constant and the period of oscillation — Use springs of different stiffness to verify the simple harmonic motion equation.

10. How does the distance from a point source affect the intensity of radiation? — Use a Geiger counter or light sensor to verify the inverse square law experimentally.

For a complete overview of IB Physics topics and formulas, check out our IB Physics revision notes.

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Chemistry IA Topic Ideas

The Chemistry IA involves designing and carrying out an experiment. Strong Chemistry IAs often link to real-world applications. Here are 10 ideas:

1. How does temperature affect the rate of reaction between sodium thiosulfate and hydrochloric acid? — The classic “disappearing cross” experiment, but with thorough data analysis and Arrhenius equation application.

2. Comparing the vitamin C content in fresh vs. stored orange juice using iodine titration — A practical investigation with real-world relevance to nutrition and food science.

3. The effect of pH on the rate of enzymatic browning in apples — Investigate polyphenol oxidase activity at different pH levels using colorimetry.

4. How does the concentration of salt affect the corrosion rate of iron nails? — Explore electrochemistry concepts with a visually measurable outcome.

5. Investigating the effectiveness of different antacids using back titration — Compare commercial antacid brands quantitatively and link to buffer chemistry.

6. The effect of catalyst concentration on the decomposition of hydrogen peroxide — Use manganese dioxide as a catalyst and measure oxygen gas production.

7. How does ethanol concentration affect the surface tension of water? — Use the capillary rise method to measure surface tension at different concentrations.

8. Determining the enthalpy of combustion of different alcohols — Burn methanol, ethanol, propanol, and butanol to compare experimental values with theoretical predictions.

9. The effect of temperature on the solubility of potassium nitrate in water — Create a solubility curve and compare with published data.

10. Investigating the electrochemical series by measuring cell potentials of different metal combinations — Build galvanic cells and compare experimental EMF values with standard electrode potentials.

For more help with IB Chemistry, explore our IB Chemistry study notes.

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Biology IA Topic Ideas

Biology IAs can be experimental or data-based. The best Biology IAs show genuine personal engagement and careful analysis. Here are 10 ideas:

1. How does light intensity affect the rate of photosynthesis in aquatic plants? — Use Elodea and count oxygen bubbles (or use a dissolved oxygen sensor) at different light levels.

2. The effect of caffeine concentration on Daphnia heart rate — A classic investigation with ethical considerations to discuss, using transparent organisms under a microscope.

3. How does soil pH affect seed germination rates? — Test multiple pH levels with the same plant species to investigate optimal growing conditions.

4. Investigating the effect of exercise intensity on heart rate recovery time — Collect data from multiple participants after different exercise levels.

5. The effect of different sugar types on yeast fermentation rates — Measure CO₂ production when yeast is given glucose, fructose, sucrose, and lactose.

6. How does antibiotic concentration affect the zone of inhibition in bacterial cultures? — Use agar plates and paper discs to investigate minimum inhibitory concentrations.

7. The relationship between leaf surface area and transpiration rate — Use a potometer to measure water uptake in plants with different leaf sizes.

8. Investigating the effect of temperature on membrane permeability using beetroot cells — Measure anthocyanin leakage at different temperatures using colorimetry.

9. How does salinity affect the hatching rate of brine shrimp eggs? — Test multiple salt concentrations to determine optimal conditions.

10. The effect of different music genres on human reaction time — A fun, data-rich investigation combining biology with psychology.

For detailed revision notes, visit our IB Biology revision guide.

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Economics IA Topic Ideas

The Economics IA consists of three commentaries based on news articles. Each commentary should apply economic theory to a real-world situation. Here are 10 article themes to consider:

1. Government intervention in housing markets — Analyse rent control policies and their effects on supply, demand, and market equilibrium using price ceiling diagrams.

2. The impact of minimum wage increases on unemployment — Evaluate the effects of wage floors using labour market diagrams and real-world data.

3. Carbon taxes and their effectiveness in reducing emissions — Apply negative externality theory and discuss the merits of market-based environmental policies.

4. Currency depreciation and its effect on a country’s trade balance — Use exchange rate diagrams and the Marshall-Lerner condition to analyse trade impacts.

5. The economic impact of tourism subsidies in developing countries — Explore positive externalities, multiplier effects, and government spending priorities.

6. Price discrimination in the airline industry — Analyse how airlines use third-degree price discrimination and evaluate its effects on consumer and producer surplus.

7. The effect of trade tariffs on domestic industries — Use tariff diagrams to evaluate protectionist policies and their welfare effects.

8. Inflation targeting by central banks — Discuss monetary policy tools and their effectiveness in maintaining price stability.

9. The economics of fast fashion and overconsumption — Apply market failure concepts including negative externalities of production and consumption.

10. Universal basic income (UBI) pilot programmes — Evaluate fiscal policy implications, opportunity costs, and potential effects on labour supply.

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Business Management IA Topic Ideas

The Business Management IA is a research project based on a real organisation. You must use primary and/or secondary research to answer a research question. Here are 10 ideas:

1. How effective is [Company X]‘s social media marketing strategy in increasing brand awareness among Gen Z consumers? — Use surveys and social media analytics.

2. To what extent has remote working affected employee motivation at [Company X]? — Apply Herzberg’s or Maslow’s motivation theory with primary research.

3. Should [local business] expand into e-commerce? — Conduct a SWOT analysis, investment appraisal, and market research.

4. How has corporate social responsibility (CSR) affected [Company X]‘s brand image? — Analyse stakeholder perceptions through surveys and published reports.

5. An analysis of [Company X]‘s pricing strategy in a competitive market — Compare pricing methods and evaluate effectiveness using sales data.

6. To what extent does organisational culture affect staff retention at [Company X]? — Apply Handy’s cultural model and collect primary data through interviews.

7. How should [Company X] adapt its marketing mix for entering a new international market? — Apply the 7Ps framework and conduct market analysis.

8. The impact of supply chain disruptions on [Company X]‘s operations — Investigate post-pandemic operational changes and contingency planning.

9. Should [Company X] adopt a lean production approach? — Analyse current waste, efficiency metrics, and potential cost savings.

10. How effective is [Company X]‘s training and development programme in improving employee performance? — Use Kirkpatrick’s evaluation model with primary research.

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Mathematics IA (Exploration) Topic Ideas

The Maths IA is a written exploration of a mathematical topic. It should demonstrate personal engagement and mathematical thinking. Here are 10 ideas:

1. Modelling population growth using logistic functions — Compare exponential and logistic models using real population data from a country or species.

2. The mathematics of RSA encryption — Explore modular arithmetic, prime factorisation, and Euler’s totient function in cryptography.

3. Optimising the shape of a container to minimise material cost — Use calculus to find the dimensions that minimise surface area for a given volume.

4. Exploring the Monty Hall problem through probability and simulation — Analyse the problem theoretically and verify through Monte Carlo simulation.

5. Modelling the trajectory of a basketball shot using quadratic and projectile motion equations — Collect video data and fit mathematical models.

6. The mathematics of musical harmony — exploring frequency ratios and consonance — Investigate why certain note combinations sound pleasant using mathematical ratios.

7. Using Markov chains to predict weather patterns — Build a transition matrix from historical data and analyse prediction accuracy.

8. Exploring the golden ratio in nature and art — Investigate Fibonacci sequences, phi, and their appearances in biological structures.

9. Modelling the spread of infectious diseases using the SIR model — Apply differential equations to epidemiological data and evaluate model accuracy.

10. The mathematics of voting systems — comparing fairness criteria — Analyse Arrow’s impossibility theorem and compare plurality, Borda, and ranked-choice methods.

For help with IB Maths formulas and techniques, see our IB Mathematics cheat sheets.

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General Tips for a High-Scoring IA

Show Personal Engagement

The IB rewards students who go beyond the textbook. Explain why you chose your topic, what challenges you faced, and how your thinking evolved during the process.

Use Proper Academic Referencing

Cite all sources using a consistent referencing style (MLA, APA, or the style your school prefers). This includes data sources, background research, and any formulas you didn’t derive yourself.

Analyse Thoroughly — Don’t Just Describe

The analysis section is where most marks are won or lost. Use graphs, statistical tests, error analysis, and clear mathematical reasoning. Go beyond surface-level observations.

Evaluate Honestly

Discuss the limitations of your work. What were the sources of error? How could the investigation be improved? Honest evaluation shows maturity and earns marks.

Keep Within the Word/Page Limit

Each subject has specific length guidelines. Exceeding them suggests poor communication skills. Be concise and focused.

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Frequently Asked Questions

How long should an IB IA be?

This varies by subject. Science IAs are typically 6–12 pages. Maths Explorations are 12–20 pages. Economics commentaries are 800 words each. Always check your subject-specific guidelines.

Can I change my IA topic after starting?

Yes, but do it early. The longer you wait, the more work you’ll need to redo. Discuss any changes with your teacher immediately.

How important is the IA for my final grade?

Very important! The IA typically contributes 20–25% of your final subject grade. A strong IA can significantly boost your overall score.

Should I choose a simple or complex topic?

Aim for a topic that’s appropriately challenging for your level. A simple topic done exceptionally well can score higher than a complex topic done poorly. The key is demonstrating understanding and thorough analysis.

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Get Expert Help With Your IB IA

Struggling to choose a topic or need guidance on your IA? Tutopiya’s expert IB tutors can help you brainstorm ideas, refine your research question, and guide you through the entire IA process.

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For more IB resources, explore our guides on writing a TOK essay, choosing between Maths AA and AI, and understanding the IB IA process.

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