experiment: align investigation response input

.claude/ux-guidelines.md

@@ -385,3 +385,11 @@ Short inputs should feel valid.
 Users may still paste longer content when necessary.
 
 Meaning and state must never depend on colour alone.
+
+Similar interactions should look similar.
+
+Every investigation answer is a single observation.
+
+Response controls should communicate concise input unless the engine explicitly requests otherwise.
+
+Consistency reduces cognitive load.

components/reasoning-workspace.jsx

@@ -681,7 +681,7 @@ export default function ReasoningWorkspace({
                       rows={4}
                       disabled={updateStatus === "loading"}
                       className="w-full rounded-lg border border-gray-300 px-4 py-3 text-sm focus:border-gray-500 focus:outline-none focus:ring-2 focus:ring-gray-400 disabled:cursor-not-allowed disabled:opacity-60"
-                      placeholder="Enter the answer to the selected question..."
+                      placeholder="What do you know about this?"
                     />
                   </div>
                   <div className="flex items-center justify-between">

docs/design-evolution-log.md

@@ -369,10 +369,52 @@ A smaller initial input will make beginning an investigation feel easier and wil
 
 Pending visual review.
 
+#### Result
+
+Confirmed.
+
+Four visible rows better communicates a starting observation than six.
+
+Input size communicates expected effort.
+
+"What have you noticed?" reinforces observational thinking.
+
+Users are encouraged to begin rather than compose.
+
+The facilitator and workspace now feel more balanced.
+
+This interaction principle should continue throughout the investigation rather than existing only on the landing page.
+
+#### Decision
+
+Retain the smaller landing input.
+
+Proceed to investigate consistency between the landing experience and investigation responses.
+
+---
+
+### Experiment 08 — Consistent Investigation Responses
+
+#### Hypothesis
+
+Every answer given during an investigation should feel like an observation, not a report.
+
+The response component should therefore communicate the same expected effort as the initial scenario input.
+
+#### Questions
+
+- Does a smaller response area reduce perceived effort?
+- Does the investigation feel more conversational?
+- Does consistency improve confidence?
+- Does the workspace become visually calmer?
+- Does the current investigation remain the dominant focus?
+
 #### Status
 
 Experimental.
 
+No conclusions yet.
+
 ---
 
 ## Current Open Questions