Natural-language analysis in Excel Copilot, Gemini in Sheets, or Claude turns "why did throughput drop?" into charts in seconds. This playbook wires in the three mandatory habits — inspect the generated logic, check filters and date ranges, reproduce one number independently — so conversational speed never launders a wrong answer into a steering deck.
Workflow area: Data & Evidence · Tier: Core · Hands-on time: ~35 minutes
The wrong-query-plausible-chart failure mode is the most dangerous artifact in the BA toolkit: the AI misreads a column, silently drops rows with null dates, or averages an average — and hands you a confident, well-formatted chart that survives every glance and no audit. The fix is not to abandon conversational analysis; it is to treat every AI-produced number as a hypothesis until you have inspected how it was computed and reproduced at least one figure by an independent route.
Stage a dataset you understand. Export the extract to a working copy and spend five minutes on orientation: row count, one row's meaning, the date column's format and range, and which columns hold codes versus labels. Note the row count — it is your first verification anchor. Remove columns you do not need, especially anything personal.
Ask the question with the verification contract attached. In Claude or ChatGPT (with the file attached), Excel Copilot, or Gemini in Sheets, use this prompt:
You are assisting a business analyst. Dataset: [ONE LINE — e.g.
"support tickets Jan-Jun 2026, one row per ticket, 8,412 rows"].
Question: [e.g. "Has average resolution time worsened over the
last three months, and if so, for which teams?"]
Rules:
1. Before answering, state: which columns you used, which rows
you excluded and why, and the exact date range applied.
2. Show the computation — the formula, code, or step list —
not just the result.
3. Report the row count feeding each figure.
4. If a column is ambiguous (e.g. two date fields), STOP and
ask which to use. Do not guess.
5. Flag any data problems you notice: nulls, duplicates,
format inconsistencies, outliers.
6. Distinguish "the data shows X" from "X might explain it" —
label any causal suggestion as HYPOTHESIS.
Inspect the logic before you read the answer. Good output leads with its working:
COLUMNS USED: created_at, resolved_at, team
EXCLUDED: 214 rows with null resolved_at (open tickets);
3 rows where resolved_at < created_at (data error, flagged)
DATE RANGE: 2026-01-01 to 2026-06-30 on created_at
ROWS IN SCOPE: 8,195 of 8,412
RESULT: Mean resolution 41.2h in Q2 vs 29.8h in Q1 (+38%).
By team: Tier-2 stable (31h→33h); Tier-1 worsened (28h→46h).
HYPOTHESIS: Tier-1's mix shifted — hardware tickets rose from
12% to 31% of their volume; hardware tickets average 3x longer.
Verify before concluding performance declined.
Read the exclusions and date range as hard questions: are open tickets supposed to be excluded from this measure? Is created_at the right anchor, or does the business count from first response?
Reproduce one number independently. Take the headline figure and rebuild it by a different route: a hand-built pivot table, a spreadsheet formula on the raw column, or a filtered row count you can eyeball. If your number and the AI's disagree, the discrepancy is the finding — chase it before anything else. Do this for at least one figure per deliverable, always the one with the most consequence.
Interrogate the pattern before you narrate it. Averages hide mix shifts, seasonality, and instrumentation changes. Ask the follow-up explicitly: "Could this trend be explained by a change in mix, a seasonal pattern, or a change in how the data is recorded? Test each against the data." In the sample above, that question converts "Tier-1 got slower" — a performance accusation — into "Tier-1's workload changed," a completely different requirement.
Write findings with their audit trail. Every number in the memo carries its scope in-line ("mean resolution, closed tickets only, Jan–Jun, n=8,195") plus which figure was independently reproduced. Anything the AI proposed causally stays labeled HYPOTHESIS until a data owner or SME confirms it.
Operational extracts routinely contain customer names, emails, and account identifiers — strip or pseudonymize personal columns before upload, use only your organization's approved AI workspace, and never move client data into a personal consumer account to dodge a licensing gap.
Conversational analysis makes the question cheap; verification is what makes the answer worth anything — inspect the generated logic, reconcile the row counts, and reproduce one number by hand, because a plausible chart from a wrong query is failure dressed as progress.