##### Scenario A company sells a product through three channels – online, phone and email – and supplies click-through and conversion rates for each. ##### Question Given impressions, click-through rate and conversion rate for each channel, compute the expected number of purchases per channel. Rank channels by conversion efficiency and overall expected revenue if an average order value is supplied. Which additional metric(s) would you request to judge channel performance more holistically? ##### Hints Conversions = impressions × click rate × conversion rate; compare per-impression or per-click ROI.

This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Determine Channel Performance with Additional Metrics Needed states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

How do I approach Analytics & Experimentation interview questions?

Analytics & Experimentation questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master analytics & experimentation interviews.

What difficulty level is this interview question?

This is a medium difficulty Analytics & Experimentation question, commonly asked during Technical Screen rounds at OneMain Financial.

What role is this question designed for?

This question is commonly asked for Data Scientist candidates at OneMain Financial during technical interviews.

Determine Channel Performance with Additional Metrics Needed

Compute Expected Purchases and Revenue by Channel

Context

A company sells a product through three channels: online, phone, and email. For each channel, you are given:

Impressions (I)
Click-through rate (CTR)
Conversion rate (CVR)
An average order value (AOV) may be supplied

Assume CTR and CVR are provided as percentages and represent:

CTR: probability of a click given an impression
CVR: probability of a purchase given a click (post-click conversion)

Task

Compute the expected number of purchases for each channel.
Rank channels by conversion efficiency.
Compute and rank overall expected revenue given AOV.
List additional metrics you would request to judge channel performance more holistically.

Formulas

Expected purchases per channel: Purchases = Impressions × CTR × CVR
Conversion efficiency (two useful views):
- Post-click efficiency: CVR
- End-to-end efficiency per impression: CTR × CVR
Expected revenue: Revenue = Purchases × AOV

Hint: Compare per-impression or per-click ROI when cost data are available.

Constraints & Assumptions

Preserve the scope, facts, inputs, and requested outputs from the prompt above.
If the prompt leaves a detail unspecified, state a reasonable assumption before relying on it.
Keep the answer interview-ready: concise enough to present, but concrete enough to implement or evaluate.

Clarifying Questions to Ask

Clarify the business objective, unit of analysis, time window, exposure definition, and primary metric.
State assumptions about instrumentation, randomization, sample size, and data quality.
Separate descriptive analysis from causal claims.

What a Strong Answer Covers

A metric framework with primary, guardrail, and diagnostic metrics.
A credible analysis or experiment design with clear assumptions and bias checks.
SQL/statistical logic for segmentation, variance, confidence, and data validation where relevant.
An actionable recommendation that explains trade-offs and next steps.

Follow-up Questions

What sanity checks would you run before trusting the result?
How would you handle novelty effects, seasonality, or selection bias?
What decision would you make if metrics disagree?