Trend Spotter
Humans are bad at spotting patterns in tabular data and worse at distinguishing real trends from noise. The Trend Spotter applies statistical rigour — baseline, seasonality decomposition, the DRIFT framework, and confidence-banded forecasts — so the insights are real rather than imagined, and the forecasts come with the assumptions that have to hold for them to mean anything.
What this skill does
Two points is not a trend. The skill requires at least three consistent data points before calling something a trend, and five before applying linear regression. Seasonality decomposition needs at least two full cycles. Correlation analysis needs at least twelve paired observations. Forecasts beyond three periods get wider confidence bands; beyond six periods, they become directional language only. If the data is insufficient for what's being asked, the skill says what's needed and refuses to stretch thin data into false conclusions.
Decompose before concluding. The most common analysis mistake is calling a December spike a "trend" when it's Christmas, or panicking at a January dip that's the same dip as every January. The skill separates the data into trend, seasonal, and residual components before reporting anything as a directional finding. A "growing 15%" claim that disappears when you remove seasonality wasn't growth; it was the calendar.
The DRIFT framework runs the analysis. Direction (up, down, flat over the window, with the slope calculated). Rate of change (is the trend accelerating or decelerating — the second derivative often matters more than the first). Irregularities (outliers beyond two standard deviations, structural breaks where the pattern shifts permanently, missing data gaps). Factors (correlations and leading indicators, where one metric moves one or two periods before another, with correlation strength and lag reported but never overclaimed as causation). Trajectory (where this is heading if the trend continues, with optimistic, baseline, and pessimistic ranges).
Forecasts come with the assumptions that have to hold for them to be useful. Point estimate, range, confidence level (GREEN/AMBER/RED based on data quantity, stability, and how far out the projection runs), the explicit assumptions, and an invalidation signal — what would tell you the prediction is wrong before the forecast horizon closes. Confidence interval language gets translated for non-technical readers ("the metric will likely land between X and Y") and traffic-light framing replaces statistical jargon. A point estimate without bounds creates false precision and never appears alone.
You get the data overview with sufficiency notes per analysis type, the baseline (central tendency, variability, seasonality pattern), the trends detected and ranked by magnitude and acceleration (not just whatever's loudest), the classified anomalies with type (spike/drop/shift/trend break/missing) and risk level, correlations with lead/lag relationships flagged for further investigation rather than concluded as causal, the forecast table across 3/6/12 periods with confidence, and a recommended-actions list keyed to the detected patterns. When the user provides many metrics, the top three to five trends become headlines and the rest go to a summary table — nobody parses fifteen trend descriptions to find the three that matter.
When this triggers
- ·You have a time series and want to know whether the recent move is a trend or noise
- ·Numbers are wobbling and you can't tell if it's seasonality, an outlier, or a structural shift
- ·You need a forecast for the next 3-6 periods with a defensible range rather than a single guess
- ·You suspect a leading indicator exists in your metrics but haven't found it
- ·A single big spike is colouring everyone's view and you need to know if it's a one-off
Example
Trigger
User: '36 months of monthly e-commerce revenue. Last 3 months down 8%, 12%, 4% vs prior year. Is this a real decline or noise?'
Output
Data Overview Range: 36 months | Metric: monthly revenue | Quality: clean Sufficient for: trend detection (yes), seasonality (yes, 3 full cycles), forecasting (3-6 periods with confidence, 12 periods directional only). Baseline Median monthly revenue: £142K | Mean: £156K (right-skewed by Black Friday months). Coefficient of variation 0.28 — moderate natural noise, expect ±£30K swings without signal. Seasonality: clear annual cycle (Nov-Dec peak +60% vs trough, Jan-Feb dip -25%). Decomposed before trend analysis. Trends Detected (after deseasonalisation) Trend 1: Underlying revenue declining since month 24 · Direction: Down · Rate: -1.2% per month, deseasonalised · Acceleration: Steady (not getting worse) · Duration: 12 consecutive months · Verdict: REAL, not noise. The recent -8%/-12%/-4% looks worse than it is because Q4 last year had an outlier campaign month — strip that and the decline is consistent at ~1.2%/month, not accelerating. Anomalies · Month 22 spike (+47%): single campaign, exclude from baseline · Month 30 drop (-22%): coincides with supplier outage, real but one-off Correlations · Email list size leads revenue by ~2 months (r=0.71) — list growth slowed 4 months ago, consistent with decline · Paid spend r=0.34 — much weaker driver than email Forecast (next 3 / 6 / 12 periods, deseasonalised) | Period | Point | Likely range | Confidence | |--------|--------|---------------|------------| | +3 mo | £132K | £122K-£142K | AMBER | | +6 mo | £128K | £112K-£144K | AMBER | | +12 mo | £121K | £95K-£148K | RED (dir.) | Key assumptions: trend continues at -1.2%/mo, no new campaign or list-growth intervention, seasonality holds. Invalidation: if email list grows >5% over next 2 months, revisit — list is the leading indicator. Recommendation: this is a sustained decline, not noise. Address email list growth first — it's the leading indicator with 2-month lag, so action now affects revenue in ~Q2.
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