Quick answer: A hypothesis can change during a systematic progression of experimental work without automatically creating a new core R&D activity. The more important question is whether the revised hypothesis and subsequent experiments remain sufficiently related to the same technical or scientific idea, or whether the work has moved to a materially different outcome that should be treated as a separate research question and experimental progression. The change — and the evidence that led to it — should be recorded while the work is happening.
11 September 2026 — this article describes the current rules. The 2026–27 Federal Budget announced proposed R&DTI reforms for income years starting on or after 1 July 2028. Until any amendments take effect, the R&DTI continues to be administered under the current legislation.
Changing the Hypothesis Is Not Necessarily a Problem
A research programme rarely unfolds exactly as it was first drawn.
An experiment may show that the suspected mechanism is wrong. A variable that looked secondary may turn out to dominate the result. A measurement method may prove too noisy to distinguish between two explanations. The team may then need to revise the hypothesis before the next experiment.
That is not inconsistent with a systematic research process.
Australian Government guidance describes a systematic progression of work as moving through hypothesis, experiment, observation, evaluation and logical conclusions. Importantly, the conclusion does not have to support the original hypothesis. The evaluation may instead lead to a different solution and a new hypothesis that requires further experimentation. The guidance also notes that experiments testing a new hypothesis may be similar enough to remain part of the same core R&D activity, or sufficiently different that they need to be treated as a new core R&D activity.
For a technical team, therefore, the question is not:
“Did our hypothesis change?”
It is:
“What exactly changed, and does the next experiment still address the same unresolved technical outcome?”
That distinction becomes important both for research design and for the record explaining why the work progressed as it did.
Keep the Uncertainty Separate from the Proposed Explanation
A useful way to think about the problem is to separate three things:
The research question: What technical outcome are you trying to determine?
The hypothesis: Your proposed explanation for how that outcome might be achieved, and why.
The experiment: The procedure used to test that hypothesis.
Those three things are related, but they are not interchangeable.
Suppose a manufacturer is investigating whether a process can maintain a required level of stability under variable operating conditions. The first hypothesis is that instability is caused primarily by temperature variation. Controlled experiments do not support that explanation. The data instead suggest that residence-time variation may be responsible.
The hypothesis changes, but the underlying question may not have changed at all. The team is still investigating whether the same process can achieve the same technical outcome under the same operating constraint. A second experiment designed to test the residence-time explanation can therefore follow logically from the first evaluation.
The situation is different if the failed experiment causes the team to abandon that objective and begin investigating a different technical outcome. For example, instead of asking whether the existing process can remain stable, the team might decide to investigate whether an alternative process architecture can achieve a different performance target.
That may be a sensible continuation of the broader project, but from a research perspective the team should ask whether the revised work still tests the same technical or scientific idea, or whether the desired outcome and technical uncertainty have changed enough to require a separately defined question, hypothesis and experimental progression. The project name staying the same does not answer that question.
The Decision Between Experiments Is Part of the Research Record
Teams often document experiments more carefully than they document the decisions between experiments. That creates a gap.
Experiment A has a test plan. Its measurements are stored. Experiment B also has a test plan. But six months later nobody can reconstruct why the team stopped varying one parameter, introduced another variable, or replaced the original hypothesis. The missing piece is the reasoning that connects the two.
Current government guidance emphasises records that demonstrate the systematic progression of work, including experimental plans, trial records, test results and evaluations. It also emphasises contemporaneous records — records created at or around the time the activities are planned and conducted — because they provide stronger evidence of what was done, why it was done and how the investigation progressed.
In practice, the transition from one hypothesis to another can be captured in a short research decision record. It might state:
• What the previous experiment was intended to test
• What was observed
• What conclusion the team drew from the result
• Which part of the previous hypothesis is no longer supported
• What uncertainty remains unresolved
• Why the revised hypothesis could explain that uncertainty
• What the next experiment will change, hold constant and measure
The purpose is not to produce documentation for its own sake. It is to preserve the logic of the investigation. If a reviewer, technical lead or new team member later reads Experiment B without Experiment A, they should still be able to understand why Experiment B exists.
The record does not need to make every early assumption look correct. In fact, a research history in which hypotheses are rejected, refined and replaced may describe the investigation more accurately than a retrospective narrative in which the final approach appears inevitable from the beginning.
Watch for Research Drift
There is another reason to make the transition explicit: a project can gradually stop investigating the question it originally set out to answer.
The first experiments may concern an uncertain technical mechanism. Later work may shift towards performance tuning, integration, user requirements, cost reduction or production deployment. Those activities may all be important to the project. They are simply different questions.
Government guidance distinguishes hypothesis-driven experimental work from implementation or established problem-solving approaches where the relevant outcome can already be known or determined from current knowledge, information or experience available to a competent professional. The fact that implementation remains difficult, expensive or iterative does not by itself make the outcome technically uncertain.
A useful checkpoint after each significant experiment is therefore:
What remains unknown that requires another experiment to determine?
If the team can state that clearly, the next hypothesis can be designed around it. If the answer has changed materially, redefine the research question rather than quietly stretching the original one. And if there is no longer an outcome that can only be determined through hypothesis-driven experimentation, the research phase may have reached its natural boundary even though the wider engineering project continues.
Conclusion
A changing hypothesis is not evidence that the research process has gone wrong. It can be the expected result of evaluating experimental evidence.
What matters is whether each change follows logically from the previous experiment, whether the remaining uncertainty is clearly defined, and whether the next experiment still belongs to the same technical investigation or marks the start of a different one.
The record should make that progression visible as it happens — not reconstruct it after the fact.
Sources & Further Reading
Talk to Ignition Research if a technical investigation has changed direction and you need to determine how the next research question, hypothesis and experimental sequence should be structured. As a Registered Research Service Provider, Ignition Research assists businesses with research question definition, experimental design, technical investigations and contemporaneous supporting records within its registered research fields.
RSP registration confirms that the provider has met the relevant registration requirements for its registered research fields. It does not constitute government endorsement of a project or guarantee R&DTI eligibility.
We do not determine R&DTI eligibility or provide tax advice. The R&D Tax Incentive is a self-assessment program, and companies remain responsible for assessing their activities, expenditure and circumstances and obtaining appropriate tax advice.
This article provides general information only and is not tax, legal or financial advice.
Working on a project like this?
Tell us what you're building and the part you're not sure will work. A researcher from our Adelaide team (registered Research Service Provider RSP000047) reads every enquiry and replies within two business days. No documents needed.
