Why has Indigo's book recommendation algorithm seen a 15% decrease in click-through rates over the past month?

Introduction

Indigo's book recommendation algorithm experiencing a 15% decrease in click-through rates over the past month is a critical issue that demands immediate attention. This decline directly impacts user engagement and potentially affects Indigo's core business metrics. I'll approach this problem systematically, focusing on identifying the root cause, validating hypotheses, and developing both short-term fixes and long-term solutions.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking there might be a seasonal component. Has this 15% decrease been compared to the same period last year?

Why it matters: Seasonal trends could explain the fluctuation and impact our solution approach. Expected answer: Yes, it's been compared and the decrease is still significant. Impact on approach: If seasonal, we'd focus on adjusting for cyclical patterns; if not, we'd investigate recent changes.

• Considering user segments, I'm curious about the distribution of this decrease. Is the 15% drop uniform across all user groups or concentrated in specific segments?

Why it matters: Identifying affected segments helps pinpoint potential causes and tailor solutions. Expected answer: The decrease is more pronounced in certain user groups. Impact on approach: We'd focus on understanding what's unique about the most affected segments.

• Thinking about recent changes, have there been any updates to the recommendation algorithm or the UI in the last 1-2 months?

Why it matters: Recent changes could directly correlate with the performance drop. Expected answer: There was a minor update to the algorithm three weeks ago. Impact on approach: We'd scrutinize the update's impact and consider rolling back if necessary.

• Regarding data integrity, has there been any change in how click-through rates are measured or reported?

Why it matters: Ensures we're dealing with a real issue, not a measurement anomaly. Expected answer: No changes in measurement or reporting methods. Impact on approach: Confirms we need to look at actual performance issues rather than data discrepancies.