flowchart TD
A{Direct participant contact?};
A -- Yes --> C{Special category population?};
A -- No --> B{Identifiable data?};
B{Identifiable data?};
B -- Yes --> C{Special category population?};
B -- No --> I{Confidentiality agreements?};
C{Special category population?};
C -- Yes --> TIER_2[TIER 2];
C -- No --> D{Implied criminality?};
D{Implied criminality?};
D -- Yes --> TIER_2[TIER 2];
D -- No --> E{Children or vulnerable people?};
E{Children or vulnerable people?};
E -- Yes --> TIER_2[TIER 2];
E -- No --> F{Special category questions?};
F{Special category questions?};
F -- Yes --> TIER_2[TIER 2];
F -- No --> G{Confidentiality agreements?};
G{Confidentiality agreements?};
G -- Yes --> H{Hardware configuration conditions?};
G -- No --> TIER_1[TIER 1];
H{Hardware configuration conditions?};
H -- Yes --> TIER_2[TIER 2];
H -- No --> TIER_1[TIER 1];
I{Confidentiality agreements?};
I -- Yes --> J{Environment conditions?};
I -- No --> TIER_0[TIER 0];
J{Environment conditions?};
J -- Yes --> TIER_2[TIER 2];
J -- No --> TIER_1[TIER 1];