7.1

What changed?

By the end of this lesson

  • Describe observations before proposing causes
  • Compare affected and reference cultures
  • Preserve a baseline before changing variables

See it

Troubleshooting begins with observation and comparison. Instead of asking only ‘what is wrong?’, ask what changed in plant material, medium, vessel, environment, timing, handling, location, or source between the current culture and an acceptable reference.

Understand it

Describe observations before proposing causes

Record observable facts before causes.

Troubleshooting starts with what was observed before assigning a cause.

Compare affected and reference cultures

Compare affected and unaffected cultures when possible.

A reference helps identify which variables or events differ without turning a correlation into proof.

Preserve a baseline before changing variables

Time and batch clustering can reveal patterns.

A preserved baseline makes later changes interpretable; changing everything first hides what was originally different.

Worked example

Two batches differ in appearance after one transfer session. Record the difference, timing and shared history. Compare source, medium, vessel and handling before changing several things at once; otherwise the original comparison is lost.

Explain your decision before opening the worked reasoning below.

Show the worked reasoning

Time and batch clustering can reveal shared sources or workflow events worth investigating.

Several simultaneous changes create competing explanations that need to remain explicit.

Important boundary

Avoid changing several variables at once before documenting the baseline.

Try it

What should happen before changing several variables in the example?

Use the worked example above to explain your answer in your own words before taking the quiz.

Lesson quiz

Assessment version: 2026-10-15-v2. Previous reading-completion markers are retained. This revised quiz has its own result.

Apply it

Use the worked example to write a short decision record: what did you observe, which rule did you apply, and what would you check before acting?

Completion marks reading progress, not a quiz pass or professional certification.