CSPA study materials
CSPA study resources

CSPA key terms

CSPA · Get comfortable with the vocabulary.

Exposure

A defined measure of insurance risk volume or time that must match the loss and claim-count population used in a rate.

Claim frequency

The number of included claims per matching exposure unit, sensitive to how claims, dates, coverage, and exposure are defined.

Claim severity

Average loss per included claim under specified coverage and expense definitions, distinguished from loss per policy or exposure.

Pure premium

Loss cost per exposure, equal to compatible frequency times severity when the component definitions use the same population and basis.

Loss development

Change from an earlier reported valuation toward a later or ultimate loss estimate, subject to the chosen data and development assumptions.

Observational unit

The entity represented by a row, such as a policy-period, claim, or payment transaction, essential for valid joins and aggregation.

Data leakage

Use of information in training or evaluation that would not legitimately be available under the intended prediction and validation design.

Target encoding

A categorical transformation based on outcomes that requires careful training-only and out-of-fold construction to limit direct response leakage.

Feature availability

The time at which a predictor would actually be accessible for scoring, which can differ from the event date recorded in a source.

Sampling weight

A factor representing how observations contribute to a target population estimate when selection rates or other relevant sampling features differ.

Link function

The specified transformation connecting a conditional response mean to a linear predictor, distinct from a transformation of each observed response.

Offset

A known contribution with a specified coefficient in a linear predictor, often log exposure in an appropriately specified insurance count model.

Odds

The ratio of event probability to its complement, a scale on which a logistic coefficient produces a multiplicative conditional effect.

Interaction

A model term allowing the effect of one predictor to depend on another, requiring conditional interpretation of coefficients and mean ratios.

Dispersion

A parameter or diagnostic concept describing variability relative to a specified mean-variance relationship, whose exact convention depends on the model family.

Leaf prediction

A tree output for observations reaching a terminal region, computed according to the response, objective, and any supplied observation weights.

Bagging

An ensemble approach that fits models to bootstrap resamples and combines their predictions, often reducing instability of flexible base learners.

Gradient boosting

A sequential fitting approach that adds model contributions guided by an objective, with learning rate and model complexity affecting behavior.

Permutation importance

A predictive importance measure based on performance change after disrupting a feature, sensitive to correlation and the evaluation design.

Partial dependence

A summary of model predictions as selected features vary across a reference distribution, which may involve unrealistic correlated-feature combinations.

Calibration

Agreement between predicted probabilities or means and observed outcomes at appropriate aggregate or conditional levels, distinct from ranking quality.

ROC AUC

A binary discrimination measure interpretable through positive-negative score ranking with appropriate handling of ties, not a direct measure of probability accuracy.

Precision

The fraction of predicted or selected positive cases that are truly positive under the specified threshold, population, and outcome definition.

Recall

The fraction of actual positive cases selected as positive, dependent on the threshold and distinct from precision or the true-negative rate.

Nested validation

An evaluation design separating model-selection procedures from outer performance estimation, intended to account for tuning as part of the fitted process.

Decision utility

A stated measure of benefit and cost used to connect predictions with an action, requiring assumptions about capacity, consequences, and uncertainty.

Prediction interval

An interval intended to describe variation of a future outcome under assumptions, rather than only uncertainty in an estimated conditional mean.

Proxy variable

A field associated with another characteristic whose omission does not necessarily remove its information or resolve fairness and permitted-use concerns.

Reproducible analysis

An analysis with sufficiently controlled data, code, transformations, splits, environment, and assumptions to explain and reconstruct its stated results.

Model monitoring

A planned process for reviewing inputs, outputs, eventual outcomes, operational behavior, and response triggers with clear responsibility after deployment.