Dynamic Conditions
Dynamic conditions evaluate at runtime based on current variable values and user actions, determining which path the user follows through the prototype. A condition might check whether a form field is filled, which plan the user selected, or how many items are in their cart.
Conditions transform linear prototypes into branching experiences that mirror how real applications respond to different inputs and states.
Why dynamic conditions create realistic user experiences
Real applications constantly make decisions. "If the user is logged in, show the dashboard. If not, show the login screen." "If the cart is empty, show the empty state. If not, show the item list." Without conditions, prototypes can only simulate one path through these decision points.
Dynamic conditions let prototypes handle all paths. During testing, each participant sees the path that matches their specific inputs, creating a realistic experience that reveals genuine usability issues rather than testing comprehension of a predetermined flow.
This matters most for features where user behavior varies significantly. A settings page where every user follows the same path does not need conditions. An onboarding flow where users choose roles, set preferences, and skip optional steps needs conditions to test the real complexity.
Building dynamic conditional logic
- Identify the decision points in your flow where different users should see different content or follow different paths. Map each decision to the variable or user action that controls it.
- Create the variables that conditions will reference. Ensure each variable has a clear type, default value, and update mechanism (user action, API response, or timer).
- Add conditions to triggers using the condition builder. Select the variable, choose an operator (equals, greater than, contains, is empty), and enter the comparison value.
- For complex decisions, create condition groups using AND/OR logic. "Show the premium banner if plan equals free AND days since signup is greater than seven" requires a two-condition AND group.
- Define a fallback path for every condition set. The fallback activates when no explicit conditions match, preventing users from hitting dead ends in the prototype.
- Test each condition path individually using the variable inspector. Set variables to specific values and verify that the correct path activates. Then test the full flow end-to-end with realistic variable changes.
Conditional logic mistakes
- Writing conditions that always evaluate to the same result because the controlling variable never changes. This creates a hidden static path disguised as dynamic logic.
- Creating condition sets without a fallback. If a user's variable values do not match any condition, they see nothing or hit an error. Always define what happens when no condition matches.
- Testing conditions only with expected values. Real users enter unexpected inputs. Test conditions with empty values, extreme numbers, special characters, and the default state.
- Using too many conditions on a single trigger. More than five conditions on one element indicates the decision logic is too complex for a single interaction and should be split across multiple steps.
- Not documenting what each condition checks and why. When a prototype has twenty conditional paths, team members need to understand the logic without reading every condition configuration.
Measuring interaction realism
- Condition path coverage: The percentage of conditional paths that have been activated during at least one test session. Unexercised paths may contain bugs.
- Fallback activation rate: How often the fallback path fires versus an explicit condition. A high fallback rate suggests conditions are too narrow and missing common user states.
- Participant path diversity: How many different paths participants take through the prototype. Low diversity might indicate conditions are not surfacing real behavioral variation.
- Condition logic errors: The number of conditions that produce unexpected behavior during review. Track this to measure whether condition logic quality is improving.
When dynamic conditions improve testing
- When the feature under test has multiple user paths that depend on prior choices, account state, or input validation.
- When you need to test error states and edge cases alongside the happy path within the same prototype instead of building separate error-only prototypes.
- When participants should see personalized content based on selections they made earlier in the session, like tailored recommendations or role-specific dashboards.
- When testing form validation flows where the prototype needs to respond differently to valid, invalid, and partially complete inputs.
Key concepts
- Dynamic condition: A rule that evaluates at runtime based on current variable values, user actions, or prototype state, determining which path the user follows.
- Condition group: A set of conditions combined with AND/OR logic to create complex branching rules.
- Fallback path: The default route taken when no conditions in a group evaluate to true.
FAQ
- Can conditions reference data from API bridges? Yes. Bind API response values to variables, then use those variables in condition expressions.
- How do I handle complex branching with many conditions? Use condition groups with clear naming and keep the total number of branches under seven per decision point for testability.
- Can I preview which condition path will fire? Yes. The condition debugger shows which conditions are active and which path will be taken based on current variable values.
Next steps
Map the conditional logic in your most complex prototype flow and verify that each branch has a defined trigger and a clear user-facing outcome. Start with the happy path, then add error and edge-case conditions incrementally.