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MEASUREMENT

Designing composite indices: how SimpleIndex and EHS normalization were built

2026.07.23Measurement Design

The numbers in the DATA LAB charts are not single raw values. They are composite indices integrating multiple subjective and semi-objective measures. Before debating "did it work," making the measurement design transparent — what was measured, and how — is what secures the data's credibility. This article explains the design thinking behind SimpleIndex and EHS normalization.

01Why a single metric isn't enough

Measuring "libido" by subjective rating alone invites the "isn't it just placebo?" critique. Physical metrics alone, conversely, drop the person's lived experience. So we placed a subjective metric (libido self-rating) and a semi-objective one (EHS = nocturnal/morning erection hardness) independently side by side, so the two channels cross-validate. Evidence weak on its own becomes stronger when both channels point the same way.

subjectivelibido self-rating semi-objectiveEHS (hardness) composite indexSimpleIndex / ProIndex
FIG 1Subjective and semi-objective measures are recorded independently, then integrated by weighting into a composite index — a design where the two channels validate each other.

02SimpleIndex and the logic of normalization

SimpleIndex is a weighted composite of libido, EHS, and morning erection duration (designed with a theoretical maximum of 100). Raw values have different units and scales, so they can't simply be added. By normalizing each metric to 0–100 before combining, different metrics can be compared and integrated on the same footing. The monthly EHS score likewise averages the 1–4 hardness rating over each 30 days and normalizes to 0–100.

DESIGN NOTES
normalize → weighted sum → EMA smoothing (α=0.30)
Because daily data is noisy, an exponential moving average (EMA, α=0.30) smooths short-term spikes while revealing the trend. Weights are defined in advance, so post-hoc tuning cannot move the conclusions.

03Transparent design builds trust

Composite indices always carry the suspicion of being "built to suit." The only way to prevent that is to fix the weights and normalization steps in advance and publish them. Our data transparently documents SimpleIndex's ceiling design (100) and known measurement issues (e.g., an unset input cap in one field) alike. Prioritizing disclosure of how a metric was built over making it look elegant — that is this dataset's design philosophy.

KEY TAKEAWAY

The DATA LAB numbers are composite indices: subjective and semi-objective measures recorded independently, then integrated via normalization, weighting, and EMA smoothing. Single-metric weakness is offset by two-channel cross-validation, and fixing the design in advance rules out "post-hoc convenience." Transparency of construction is prioritized over visual polish.

Note on scope. This article summarizes general findings from published research alongside observational patterns from our own project (n=2). It is not medical advice, and n=2 observations are illustrative, not statistically generalizable.

See the 360-day measured data

The records referenced in this article are published as actual trajectory charts on our DATA LAB page — daily records from two subjects over 360+ days with near-zero missing entries.

View DATA LAB →

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