The first step of problem solving is

In the standard research-based problem-solving sequence, each stage depends on the one before it:

1. Identify and clearly state the problem.

2. Formulate a hypothesis — a possible explanation.

3. Collect the data needed to examine that hypothesis.

4. Test the hypothesis against the collected data.

Among the four listed actions, only one does not depend on any of the others already having happened: recognising and stating the problem. A hypothesis needs something specific to explain; collecting data needs a defined question to know what is relevant; and testing needs both a hypothesis and data already in hand. So identification of the problem is the step that must occur before the rest can even begin.

• Formulation of hypothesis: proposing an explanation requires something specific to explain, so it cannot be the opening move.

• Data collection: deciding what data is relevant requires already knowing what is being investigated, so it cannot be the opening move.

• Testing of hypothesis: checking an explanation against evidence requires a hypothesis and data to already exist, so it is not the opening move.

Problem identification is the only one of the four actions that requires nothing else to have happened first — which is why it is the correct first step.