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Ankit Raj Mehta
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How we proved eRuchi's recommendation engine works, with real data

first posted on LinkedIn ↗

A behind-the-scenes look at a data analysis project at eRuchi, where we put our recommendation engine to the test in real-world conditions.

The challenge

Our team needed to validate whether the recommendation system I architected could deliver measurable value in actual usage. The algorithm uses a pairwise interest-similarity scoring approach designed specifically for eRuchi’s needs.

The goal: show that our tech can match users to what they care about, not just in theory but in practice.

The experiment

We ran a controlled study:

  • Experiment group: received personalised recommendations from our engine
  • Control group: received random suggestions

We tracked genuine user responses to these recommendations across several days.

What we found

  • A big boost in positive engagement. The experiment group was much more likely to say “Absolutely interested” to our suggestions.
  • Fewer negative reactions. Strong negative responses (“Not at all interested”) decreased substantially.
Bar chart: 33.33% Absolutely and 7.27% Not at all in the experiment group, against 2.22% and 22.22% in the control group
Extreme responses: Absolutely vs Not at all
Bar chart: 83.6% positive and 16.4% negative feedback in the experiment group, against 60.0% and 40.0% in the control group
Positive vs negative feedback

Statistical confidence

  • p-value: 0.0013, a highly significant result
  • Cohen’s d: 0.82, a large effect size

Together these say the improvement in the experiment group is both statistically significant and practically meaningful.

Chi-square test charts comparing observed and expected positive and negative counts for the experiment group (138 observed vs 129.6 expected positive) and the control group (27 vs 35.4)
Chi-square test: observed vs expected frequencies

Interestingly, the control group had more plain “Yes” responses. Two possible explanations:

  1. Bias toward neutral responses. Users in the control group may have leaned toward “Yes” as a safe, middle-ground answer.
  2. Polarisation in the experiment group. Tailored suggestions might have prompted stronger opinions: more “Absolutely” and “Not at all”, fewer “Yes”.

These are theoretical interpretations and would need further analysis to confirm.

Three charts comparing the experiment and control groups across ratings A, Y, N and X, by count, by percentage and as a trend line; the control group has 57.8% Y against 50.3%
The full comparison across all four ratings (A: absolutely, Y: yes, N: no, X: not at all)

Why it matters

This analysis gave us clear, data-backed evidence that eRuchi’s matching engine delivers real value to users by helping them discover what genuinely aligns with their interests.