Lydia Mezqevri

Areas of practice

Ask what the reader is entitled to conclude

01

Preserving the level at which an amount is meaningful

I examine what each row represents before allowing an amount to travel through a join or aggregation. An order amount can appear on several delivery-event rows without becoming several orders. In my own approval error, eighty synthetic orders became 120 joined rows and an ₹8 lakh account acquired a misleading ₹12 lakh sum. The repair needed a preserved relationship between the records, not simply a different label on the total. I ask which measures belong to an order, an event or another entity, and how the intended question uses them. This is analytical stewardship rather than authority over accounting policy or customer charging. A clear relationship helps commercial and financial owners interpret their evidence without inheriting a duplication that the data structure has made easy to overlook.

02

Interpreting overlapping responses without inventing exclusive groups

I keep the response format attached to a survey finding. If an adult can select guitar, keyboard and percussion interests, the category counts need not sum to the number of participants. Our one-hundred-person study produced 150 selections, and the percentages could legitimately total 150%. That did not create 150 different people or tell us every intersection between the categories. I help colleagues choose a presentation that preserves this meaning while keeping the research useful. A mutually exclusive market-share chart would have answered a question the study did not ask. The capability includes explaining what the respondents' interests can inform and what would require a different design, without promoting a descriptive study into a population demand forecast or treating overlap as an error that must be removed.

03

Keeping unfinished service observations in the account

A completed-job report can be accurate about its included jobs while giving a misleading impression of the whole intake. Sixty closed repairs had a four-day median, but forty other jobs from the same hundred remained open for at least ten days. I ask that the cohort, status and observation cutoff remain visible before a service claim is made. Unfinished work has already supplied some elapsed-time evidence even though its eventual duration is unknown. The appropriate analysis needs qualified attention to that condition rather than a fabricated completion date or silent exclusion. My data team supports the account; service leaders own repair operations and technical decisions. The result should help them see which question the measure answers without claiming that a revised report itself shortened a customer's wait.

04

Matching analytical confidence to assignment and presentation

I examine how evidence was produced before deciding how strongly its result can be stated. Six hundred visitors observed across twelve randomised shops do not become six hundred independently assigned experimental units. Similarly, displayed ratings of 4.4 and 4.5 can arise from means of 4.44 and 4.46; the visible gap does not describe the full precision or the quality of the underlying review cohorts. These are different issues, but both require the proposed conclusion to retain its basis. I work with qualified analysts and the owners of customer-facing decisions to make those conditions understandable. I do not infer that a pilot has no effect or that one product is superior merely because an earlier claim was too strong. A correction should narrow the conclusion accurately while preserving the useful evidence.

How I lead

A calculation can be correct for its rows and wrong for the question printed above it. I try to keep the observation visible as records are joined, responses overlap or an unfinished service waits beyond the reporting date. The useful data product is an explanation another executive can rely on without silently inheriting assumptions its builders have stopped noticing.

At scale

The responsibility, in figures

24

Data colleagues

Four leads within the function remit

₹5.6 crore

Annual function expense

Separate ₹1.4 crore approved data programme

27 years

Research and data career

Analyst from July 1999; CDO from January 2022

In practice

Decisions and their consequences

Case I

I approved a join that repeated the order amount

In 2021 I approved a report joining order records to their delivery events. Our synthetic review contained eighty orders at ₹10,000 each, a total of ₹8 lakh. Forty orders had one event and forty had two. The join therefore produced 120 rows. Summing the repeated order amount across those rows gave ₹12 lakh, which the report presented as though another ₹4 lakh of orders existed. The arithmetic followed the rows; my approval had failed to preserve what the amount described.

The reporting team wanted one joined table because it made event detail readily available to commercial readers. That convenience was real. The alternative I supported kept the relationship but prevented an order-level amount from being treated as an event-level additive measure. We corrected the analytical account and funded ₹37 lakh of rebuilding and review. The work delayed the report's intended use and required colleagues to revisit conclusions drawn from its earlier presentation.

Finance retained accounting policy, and operating teams retained actual deliveries. This was not a customer-charge correction, a stock recovery or a financial restatement. The eighty-order example was synthetic and intentionally simple enough to expose the relationship. It did not establish that every historical report had the same error or that every joined dataset should discard event detail. The problem was the meaning attached to the sum, not the existence of a useful connection between two kinds of records.

I retained responsibility for accepting the treatment before asking what each resulting row represented. The corrected account made the order total and event count separately understandable. It did not produce sales or prove a universal end to duplication. The experience changed my approval question: before asking whether a report reconciles internally, I ask whether its measures still belong to the entities the reader thinks they describe.

Case II

The study had one hundred people and 150 legitimate selections

A 2022 study invited one hundred adult participants to select any of three musical interests. Sixty selected guitar, fifty-five keyboard and thirty-five percussion. These were 150 selections from one hundred people, not 150 separate respondents. The associated percentages were 60%, 55% and 35% of participants, and their sum of 150% was consistent with the multiple-response question. A proposed presentation instead placed the categories into a 100% stacked market-share chart.

The commercial sponsor wanted the chart to guide the relative prominence of demonstration areas. A single complete bar seemed easier to discuss than overlapping categories. I agreed that the study should inform the conversation, but the chart would have converted interest in several instruments into mutually exclusive segments. Dividing by 150 would describe shares of selections, not shares of people or market demand. Neither interpretation could be substituted silently for the question participants answered.

The study and reanalysis cost ₹19 lakh. We withdrew the exclusive market-share presentation and retained category counts with the respondent denominator and the multiple-selection instruction. The marginal counts did not establish every overlap between groups, so we did not invent those intersections. Product and commercial owners retained decisions about the demonstration proposition and any further research needed before committing to a broader demand claim.

The result was a more faithful use of the study, not a conclusion that one category should receive a particular floor area or investment. The tradeoff was a less mechanically simple chart and a discussion that had to acknowledge customers with several interests. I wanted the research to remain useful without forcing people's answers into exclusive boxes for presentation convenience. A percentage above one hundred in total can reveal a valid question design rather than an error, provided the reader is told what the percentages actually count.

Case III

Forty open repairs were absent from the four-day story

In 2023 a service cohort contained one hundred accepted repair jobs. Sixty had closed by the reporting cutoff, with a median completed duration of four days. Forty were still open and had already waited at least ten days. The proposed service headline used the four-day median without making its closed-job restriction prominent. It described the completed subset correctly but invited a wider interpretation about the whole intake that the account could not support.

Service colleagues wanted a stable measure that could be published regularly. Open work had no final duration and appeared awkward to include in a simple turnaround statistic. Elena Vezqemri, the fictional service head, needed an account useful for operations rather than a statistical objection with no practical next step. I recommended keeping the cohort and cutoff visible, with completed durations and open-job elapsed time distinguished, while qualified analysts examined the appropriate treatment of unfinished observations.

We funded ₹44 lakh of cohort and status reconstruction. No final duration was imputed to the open jobs, and this case does not supply an invented overall median. Their eventual completion times were unknown, but the time already elapsed was evidence. Excluding them silently would have made the fastest-to-close part of the intake speak for everyone. Service leaders retained repair priorities, technical diagnosis and customer commitments.

The revised account gave up one convenient headline and required more explanation. It did not itself speed up repairs or prove a deterioration in service. The decision concerned the claim management could responsibly make from the observations available. I would now specify the intended population when a service measure is commissioned, including how unfinished work will remain visible. A job does not become analytically irrelevant because it is taking longer than the reporting period allows us to observe fully.

Case IV

The pilot randomised shops, while its headline counted visitors

A 2024 customer-explanation pilot randomly assigned twelve shops, six to each arm, and observed six hundred adult visitors across them. The intervention was delivered through the shop setting. A preliminary analysis was being described as though all six hundred visitors had been independently randomised. The number of observations was substantial, but it did not alter the level at which assignment occurred or remove possible similarity among experiences within a shop.

The sponsor wanted to use the visitor count to support a rapid rollout decision. The programme had cost ₹58 lakh and colleagues wanted its evidence to produce a clear answer. I supported using the observations, but held the overconfident inference pending qualified cluster-aware review. This case does not report an effect size, significance result or final rollout conclusion. It records a decision to align the analysis and confidence statement with the design actually used.

The review needed to retain the twelve assigned shops, the six-per-arm allocation and the individual observations without pretending they were interchangeable units. Shop-level assignment can be appropriate for an intervention delivered collectively. The mistake was not that the team had chosen it; the mistake was allowing the subsequent interpretation to read as though a different experiment had occurred. Customer-facing owners retained implementation, and privacy and legal colleagues retained permission and appropriate-use responsibilities.

We accepted a slower decision and further analytical work instead of preserving the strongest preliminary claim. That did not establish that the explanation programme lacked value. It established that confidence in its effect required an account consistent with the assignment. My contribution was to keep the design inside the conclusion, so a large visitor number did not become a substitute for understanding how the evidence had been produced.

Case V

A tenth of a rating point concealed a smaller underlying difference

In 2025 we reviewed the display of two illustrative product-rating means, 4.44 and 4.46, derived from different voluntary review cohorts. Rounded to one decimal place, they appeared as 4.4 and 4.5. The visible difference was 0.1, while the unrounded difference was 0.02. A proposed comparison treated the displayed step as though it directly measured a meaningful quality advantage. The decimal convention had become stronger evidence than the review account supported.

Commercial colleagues wanted a simple rating presentation and a clear ordering for customers scanning products. I did not argue that every additional decimal should be displayed or that the two products were identical. The underlying means also could not settle population quality without the review counts, distribution, selection and context. My concern was that a compact interface should not invite a conclusion the data owner could not explain once asked what lay behind the rounded values.

We funded ₹26 lakh of display-definition and review-context work. Product owners retained the interface decision, with a consistent rounding rule and an explicit account of what the measure represented. We did not create a hidden precision-based superiority claim or call the visible gap five times better quality. The example demonstrates arithmetic and presentation, not a measured customer response or a verified ranking between actual products.

The tradeoff was further work on a display that initially appeared straightforward. More precision alone would not repair the inference, and a simpler chart did not excuse it. I wanted colleagues to distinguish rounding from the strength of the review evidence and then decide how much comparison the interface should encourage. A data leader's role includes the meaning of the number after it reaches a screen, especially when an ordinary presentation convention makes a small difference look like a more decisive judgement.