How do I approach Statistics & Math interview questions?

Statistics & Math questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master statistics & math interviews.

What difficulty level is this interview question?

This is a medium difficulty Statistics & Math question, commonly asked during Onsite rounds at Meta.

What role is this question designed for?

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

Analyze View Distribution and Recommendation Overlap in Videos

Quick Overview

This question evaluates statistical competence in analyzing heavy-tailed view distributions and measuring recommendation overlap, testing skills such as data visualization, computation and interpretation of mode/median/mean/99th percentile, and statistical assessment of overlap in top-10 video lists for a Data Scientist.

Short-Video Platform: View Distribution and Recommendation Overlap

Context

You are analyzing a short-video platform. You have:

A dataset of per-video view counts over a fixed time window (e.g., last 30 days).
Two users whose top-10 recommended videos (or top-10 consumed videos) frequently include identical items.

Assume view counts are nonnegative integers and video identity is deduplicated (e.g., by content hash, not just URL) to avoid counting re-uploads separately.

Tasks

Distribution of video-level views

Describe how you would visualize the distribution of views per video.
Report the mode, median, mean, and 99th percentile of the distribution.

Overlap in top-10 videos between two users

Statistically evaluate whether frequent overlap in two users' top-10 lists is desirable or a potential problem.
Explicitly consider heavy-tail effects (Zipf-like distributions), and discuss trade-offs between diversity and homogeneity.

Hints

Expect a heavy-tailed, long-tail distribution (often Zipf/Pareto-like).
Weigh personalization and diversity against the benefits of showing trending, high-quality content.

Quick Overview

Context

You are analyzing a short-video platform. You have:

A dataset of per-video view counts over a fixed time window (e.g., last 30 days).

Two users whose top-10 recommended videos (or top-10 consumed videos) frequently include identical items.

Assume view counts are nonnegative integers and video identity is deduplicated (e.g., by content hash, not just URL) to avoid counting re-uploads separately.

Tasks

Distribution of video-level views

Describe how you would visualize the distribution of views per video.

Report the mode, median, mean, and 99th percentile of the distribution.

Overlap in top-10 videos between two users

Statistically evaluate whether frequent overlap in two users' top-10 lists is desirable or a potential problem.

Explicitly consider heavy-tail effects (Zipf-like distributions), and discuss trade-offs between diversity and homogeneity.

Analyze View Distribution and Recommendation Overlap in Videos

Quick Overview

Short-Video Platform: View Distribution and Recommendation Overlap

Context

Tasks

Hints

Solution

Comments (0)

Analyze View Distribution and Recommendation Overlap in Videos

Quick Overview

Short-Video Platform: View Distribution and Recommendation Overlap

Context

Tasks

Hints

Solution

Comments (0)