Glossary

Quick reference for terms that appear in the codebase, the training, and the docs. Cross-cutting — covers both CPI domain terms and Odoo/system terms.

For the full explanation of how the CPI is computed, see CPI Concepts.

CPI / Statistics terms

Basket The set of items a typical household consumes, used as the reference for measuring price changes. In HCPI, baskets are modelled as consumption segments (one per consumer group, e.g. "urban high-income", "rural"). The model is hcpi.consumption.segment.

Base period (reference period) The period to which the current period's prices are compared. Conventionally given the value 100. A CPI of 117.3 means current prices are 17.3% higher than the base period.

Class (COICOP) The third level of the COICOP hierarchy. Sits below Group and above Sub-class. Model: hcpi.class. Example: "01.1.1 — Bread and cereals."

COICOP Classification of Individual Consumption by Purpose. The international standard for categorizing household consumption, published by the UN Statistics Division. HCPI uses all six levels: Division → Group → Class → Sub-class → Micro-class → Elementary aggregate. Owned by the hcpi_coicop module.

Composite weight The weight assigned to a level of the COICOP hierarchy, representing that category's share of household spending. Each higher level's composite weight is the sum of its children's. Field name: composite_weight on every COICOP model.

Consumption segment HCPI's term for a basket. A grouping of similar consumers used to compute basket-specific CPIs. Model: hcpi.consumption.segment.

CPI (Consumer Price Index) A single number measuring the cost of a typical household's consumption against a base period. The headline output of the HCPI system.

Division (COICOP) The top level of the COICOP hierarchy. There are 12-14 of them in standard COICOP, like "01 — Food and non-alcoholic beverages". Model: hcpi.division.

Domestic index An index restricted to domestic (non-imported) items or markets. Model: hcpi.domestic.index.

EA See Elementary aggregate.

Elementary aggregate (EA) The deepest (sixth) level of the COICOP hierarchy. Items within one EA are treated as substitutes for each other — averaged using a simple geometric mean, with no further weighting below the EA level. The base for item creation. Model: hcpi.elementary.aggregate.

Enumerator The person who visits outlets to record prices. Called data_collector in the codebase (data_collector_id on hcpi.data.collection).

Geometric mean The Nth root of the product of N values. Used below the EA level to average price relatives without weighting. Robust to outliers compared to arithmetic mean.

Group (COICOP) The second level of the COICOP hierarchy. Sits below Division and above Class. Model: hcpi.group. Example: "01.1 — Food."

Index A value computed from price relatives at some level of aggregation (per basket, per COICOP level, per month). In HCPI, every model with .index in its name is a stored computed index. The headline CPI is hcpi.national.index.

Inlier A price observation not flagged as an outlier by the Tukey algorithm — a "normal" price. Field: is_inlier (computed) on hcpi.data.collection.line.

IQR (Interquartile range) The difference between the third quartile (Q3) and the first quartile (Q1) of a dataset. Used by the Tukey algorithm: any observation outside [Q1 − k·IQR, Q3 + k·IQR] is an outlier.

Item A specific good or service whose price is collected (e.g. "white rice, 1 kg, retail"). Belongs to one elementary aggregate. Model: hcpi.item.

Laspeyres index A CPI formula that uses base-period quantities as weights. The most common CPI methodology globally. HCPI's index computation follows this approach (weighted by base-period basket composition).

Long-term price relative The ratio of the current price to the base-period price. The unit of CPI computation. Stored on hcpi.outlet.item.observation.

Median The middle value when a dataset is sorted. Robust to outliers. Used by the Tukey algorithm.

Micro-class (COICOP) The fifth level of the COICOP hierarchy. Sits below Sub-class and above Elementary aggregate. Model: hcpi.micro.class.

National index The headline CPI value — the index computed nationally across all baskets and all COICOP levels. Model: hcpi.national.index. Unique per (coicop, month).

Observation A single recorded price — what an enumerator types into the questionnaire. "On date D at outlet O, item I cost X". Model: hcpi.outlet.item.observation. Many millions accumulate over the system's lifetime.

Outlet A physical or logical point where prices are collected — a shop, a market stall, a supermarket. Model: hcpi.outlet.

Outlet item A junction record linking one outlet to one item it sells, with the item's base_price at that outlet and the time series of observations. Model: hcpi.outlet.item.

Outlet type A categorization of outlets — supermarket, retail, wholesale, market stall. Model: hcpi.outlet.type.

Outlier A price observation flagged as anomalous by the Tukey algorithm. Field: is_outlier (computed) on hcpi.data.collection.line. Reviewed by supervisors during the validation state of the workflow.

Price relative A ratio: current price ÷ reference price. CPIs are built by aggregating price relatives, not raw prices. HCPI stores both long-term (vs. base period) and short-term (vs. previous month) relatives.

Questionnaire The collection of price observations for one outlet visit. Model: hcpi.data.collection. Has a state machine: draft → survey → standardization → validation → done.

Short-term price relative The ratio of the current price to the previous month's price. Used for month-over-month change detection and outlier flagging. Stored on hcpi.outlet.item.observation.

Standardization The step in the workflow where observed quantities (e.g. "350 g sachet") are normalized to the item's standard unit (e.g. "per kg"). A state in the hcpi.data.collection state machine.

Sub-class (COICOP) The fourth level of the COICOP hierarchy. Sits below Class and above Micro-class. Model: hcpi.sub.class.

Supervisor The person who reviews and validates questionnaires after the enumerator collects them. Field: data_supervisor_id on hcpi.data.collection. Belongs to the group_data_collection_supervisor access group.

Tukey algorithm A robust outlier-detection method using the median and interquartile range. Flags as outliers any observations outside [Q1 − k·IQR, Q3 + k·IQR] where k is typically 1.5 or 3. HCPI's primary outlier filter.

UoM (Unit of measure) / UoO (Unit of observation) The units in which prices are recorded — kg, litre, piece, packet. Model: hcpi.uoo (Unit of Observation).

Weights (CPI) Numbers attached to COICOP categories representing their share of household spending. Derived from expenditure surveys. Without correct weights, the CPI doesn't reflect real consumer experience.

Zero-price observation An observation with a recorded price of zero. Usually means the item was out of stock, not actually free. HCPI's hcpi_computation mixin checks that there are at least 6 safe months and no more than 5 problematic items before allowing index computation.

Odoo / system terms

Action (Odoo) A record describing what to do when a menu or button is clicked. Most common type: ir.actions.act_window (open a list/form for a model). See Odoo Basics.

Addons path The addons_path setting in hcpi.conf — a comma-separated list of folders where Odoo looks for modules. Each folder is expected to contain module folders.

Admin password (master password) The admin_passwd value in hcpi.conf. Used for database-level operations (create, drop, backup) through Odoo's web DB manager. Not the same as a user login password. See User Administration.

Developer mode Odoo UI mode that exposes technical info (model names, view IDs) for diagnostic and developer use. Activate via Settings → "Activate the developer mode" or append ?debug=1 to a URL.

Domain Odoo's filter expression syntax — e.g. [('active', '=', True), ('district_id.name', '=', 'Kampala')]. Translates to SQL WHERE clauses via the ORM.

Field (Odoo) A column on a model — i.e. a Python attribute on the model class that becomes a DB column. Many field types: Char, Integer, Many2one, One2many, Many2many, etc.

Form view A view that shows one record laid out for editing. XML tag: <form>.

Group (Odoo security) A permission group. Users belong to groups; groups have CRUD permissions on models (via ir.model.access.csv) and can be restricted from menus. Examples: coicop_user, coicop_manager, group_data_collection_supervisor.

ir.actions.act_window The Odoo model storing "open a list/form view" actions. Stored in DB; populated from XML records on module install/upgrade.

ir.cron Odoo's scheduled-job table. Used by the secretariat hub to schedule data syncs from country instances.

ir.model.access.csv A CSV file in each module's security/ folder defining CRUD permissions (perm_read, perm_write, perm_create, perm_unlink) for each model × group combination.

ir.rule The Odoo model storing record-level access rules. A rule is a domain that automatically filters queries against a model for a given group. Used for "users can only see records in their region" patterns.

ir.ui.view The Odoo table storing all views. Populated from XML records on module install/upgrade.

List view (tree view) A view showing many records as a table. XML tag: <list> (modern) or <tree> (older — same thing).

_inherit A Python attribute on an Odoo model that says "extend this existing model" rather than create a new one. Used heavily by HCPI's country overlays (e.g. ug_outlet extends hcpi.outlet).

Manifest (__manifest__.py) The metadata file at the root of every Odoo module. Declares the module's name, dependencies, version, data files, and assets.

Menu A clickable label in the navigation. Model: ir.ui.menu. Populated from <menuitem> records in XML.

Model (Odoo) A Python class declaring an _name attribute. Becomes a database table; each instance is a record.

Module (Odoo) A folder under addons_path containing __manifest__.py, Python models, XML views, security, etc. The smallest unit of Odoo deliverable functionality.

ORM Odoo's Object-Relational Mapper. The Python interface for reading and writing data without raw SQL. Core methods: search, browse, read, create, write, unlink.

OWL Odoo's frontend JavaScript framework, similar in spirit to React. Used by hcpi_dashboard and the secretariat hub for interactive UI components.

queue_job Third-party module (OCA) that runs Python jobs asynchronously in background workers. HCPI uses it for long-running index computations. Configured in the [queue_job] section of hcpi.conf.

Recordset A list-like Odoo object holding zero or more records of the same model. The return type of search() and browse().

Search view A view defining the search bar's filters and group-by options. XML tag: <search>.

server_wide_modules A hcpi.conf setting listing modules that must be loaded into the Odoo process at startup, before any database is opened. For HCPI: base,web,queue_job.

-u <module> Command-line flag for odoo-bin. Tells Odoo to upgrade a module — re-read its XML, run any migrations, refresh views. Used after editing source files.

--dev=xml (or --dev=all) Command-line flag that makes Odoo re-read XML view files on every request. Lets you iterate on view changes without restarting. --dev=all adds Python module reloading and other dev affordances.

Wizard (Odoo) A transient model (models.TransientModel) used to drive multi-step user interactions — typically a form that collects inputs, runs an action, then disappears. Heavily used in hcpi_index for triggering computations.

web_progress Third-party module providing UI for long-running operations — a modal with progress percentage and a "run in background" button. Wired into the index-computation wizards.

XML-RPC The protocol the EAC Secretariat hub uses to pull CPI snapshots from country instances. Odoo exposes every model method over XML-RPC by default.

HCPI-specific terms

EA-level computation Computation of indices at the elementary-aggregate level — the bottommost layer above which weighting kicks in. Model: hcpi.basket.elementary.aggregate.index. Triggered by the ea.index.update wizard.

hcpi-files.zip The archive produced by the extraction guide containing a country's conf/ and custom/ folders. The deployable artifact for installing HCPI on a new machine.

hcpi.dump A PostgreSQL custom-format database dump produced by pg_dump -Fc. Restored with pg_restore. Part of the extraction artifact set.

HCPI Harmonized Consumer Price Index. The product. Also the name of the Odoo module set that implements it.

Master password See Admin password.

Mtnce branch Maintenance branch — e.g. ke_18_mtnce, tz_18_mtnce. Holds the released/maintained variant of a country branch.

Outlet code The string identifier on hcpi.outlet, validated against a strict format like 255.53.21.03.003.

Overlay module A country-specific module (ug_*, ke_*, tz_*, zar_*) that extends the shared hcpi_* core. See Country Variants.

ZAR (in this codebase) Zanzibar, not South Africa or the South African Rand. The zar_* modules customize HCPI for Zanzibar. Easy to confuse — be careful.