Snag AcademyInvestigator
It looks complete. Is it?
How the difficulty is pitched
The fault is functionally hidden — everything looks present, and one causal step explains the failure.
Now a case can hold one link of reasoning: no seal, so no pressure. The child has to hold two ideas together.
What a child at this stage can actually do
The jump from Explorer is not about harder vocabulary. It is that a case can now hold one link of causation: no gasket, so no seal, so no pressure, so the food stays hard. The child has to keep two things in mind at once and connect them.
The second shift is harder and more valuable. At this band, everything visible can be present and correct and something can still be wrong. That is genuinely uncomfortable for a child used to hunting for a gap, and learning to sit with it is most of the point.
This is also where the cases about people begin in earnest. A queue, a team being picked, a pond full of well-meant bread: these are treated as systems with diagnosable faults, in exactly the same four categories as a bicycle.
The four kinds of snag, at this level
- Missing — absent, but not visible. The rubber gasket lives inside the lid, and its absence shows only as steam escaping where it should not.
- Wrong — present, working perfectly, and the wrong choice. Top gear is not broken on a hill.
- Extra — something added that does its damage slowly, so nobody connects cause to effect.
- Order — a step whose dependency is invisible. Glue that has to dry before it can grip.
Cases at this level
The Curd That Went Too Far
It set perfectly at six. By noon it is sour. Nothing failed — nobody stopped it.
The Bridge, Not the Tracks
Ninety seconds, or a risk whose failure mode is unsurvivable.
The Last Pick
The same child is left standing every day. The fault is the method, not the child.
The Kindness That Hurt the Pond
Every Sunday a family throws in a little food. Within a year the fish are dying.
Open the app — free, no sign-up
Where children usually get stuck
Looking for something broken. At this band nothing is broken, and a child who keeps hunting for damage will stall. The useful prompt is not "what is broken?" but "what does this system need, that it has not got?"
Solving by elimination. Four options, three obviously silly, so the answer is the fourth. That gets the star and teaches nothing. The fix is one question after they answer: why does that one cause this? If they cannot say, they guessed, and it is worth going back.
Assuming the values cases have a kind answer rather than a correct one. Several do not. The pond case in particular ends with well-meaning people having caused real harm, and children often resist that conclusion. Letting them argue it out is the exercise.
What the first week usually looks like
The Technical Note becomes readable by the child themselves at this age, and it is where the actual teaching lives. The two hints on every case are deliberately written as questions rather than answers, so taking a hint is not the same as being told.
Expect arguments about particular cases. That is the intended behaviour, not a defect, and a child who can say why they think a case is wrong is doing the thing the app exists to grow.
Ready for the next band?
The signal is a change in the question they ask. When "it works" stops being a satisfying answer, and they start wondering what a fault is costing even while everything runs, they are thinking like an Inspector.
Bands switch at the top of the app at any time, and nothing is lost by moving up and back.
Alongside the app
- Notes — writing about diagnosis and safety, with every claim checked against its source.
- How to get more than screen time out of it — the "teach it back" habit is worth more than the next case.
Other shelves
👀 Explorer (Class 1–5) · 🕵️ Inspector (Class 9–12) · Under 5 years? · High-contrast cards for babies