Step 1: Identify the context clue: "even her colleagues found them hard to believe". This signals the findings were extraordinary or unbelievable.\nStep 2: Check each option:\n- "Incredible" means unbelievable or extraordinary — matches the clue.\n- "Insignificant" means unimportant — does not match.\n- "Predictable" means expected — opposite meaning.\n- "Familiar" means well-known — opposite of the clue.\nStep 3: Select "incredible" as it best fits the context.\nAnswer: incredible