Glossary

This page defines the terms the help pages use. Each entry states what the term means and how the product uses it, and the pages link here the first time a term appears. The entries are in alphabetical order. If a word you meet in the product is not here, search for it in the box above, because it may be explained on the page for the feature that uses it.

ACS

The American Community Survey, which the Census Bureau runs every year by sending a questionnaire to a sample of households. It asks about income, housing, education, how people get to work and much else that the ten-yearly census does not ask. Because it is a sample and not a count, every ACS figure comes with a margin of error. MarketGround uses the five-year ACS, which pools five years of answers so that even a small neighborhood has enough responses to report. When a page says "ACS 2024", it means the five-year release that ends in 2024, which covers answers from 2020 through 2024.

Area

The place you are asking about. In MarketGround an area is any shape on the map, whether a circle you drew, a polygon you traced, a travel time, a set of rings, a named boundary such as a ZIP code, or a site you uploaded. Every figure in the product is a figure for an area. A saved area belongs to a project and keeps its name.

Benchmark

A comparison figure for a larger place that contains your area, so that a number has something to be judged against. MarketGround benchmarks an area against its city, its county, its metro and the nation. Median income of $91,000 means more once you can see that the metro's median is $78,000. On a paid plan the analysis page shows the benchmarks beside each figure and turns them into an index.

Block

The smallest piece of geography the Census Bureau publishes, usually one city block bounded by streets, and in the countryside a larger piece bounded by roads, streams or property lines. The ten-yearly census counts every person by block. MarketGround uses blocks to decide how much of a block group's population falls inside a shape that cuts through it.

Block group

A cluster of blocks that is the smallest geography for which the ACS publishes figures. A block group holds between about 600 and 3,000 people. The country has about 240,000 of them. When you draw an area, MarketGround finds the block groups it touches, works out what share of each one's people live inside your line, and adds up those shares. A page that mentions "the block groups in your area" means these pieces.

Boundary

A named geography with an official edge, as opposed to a shape you draw. MarketGround can use a ZIP code area, a city, a county, a metro or a census tract as an area in its own right. Boundaries are part of the Pro and Team plans.

Capture

MarketGround's word for one monthly snapshot of the businesses listed in its sources. Because a new capture is taken every month, the product can tell when a business first appeared and when it stopped being listed, which is how the Businesses tab reports what opened and what is no longer listed.

Census

The count of every person in the country that the Census Bureau makes every ten years, most recently in 2020. It is a count, not a sample, so it carries no margin of error, but it asks only a few questions. MarketGround uses the 2020 census for exact population at the block level and the ACS for everything the census does not ask.

Combined total

The number of people in all of a project's areas counted once. When two saved areas overlap, adding their populations would count the people in the overlap twice. The combined total counts them once, and the side panel shows the overlap beside it so you can see how much the areas share.

Consumer unit

The household-like unit the Bureau of Labor Statistics uses in its spending survey. It is a group of people who share major expenses, so a household of roommates who keep separate finances is more than one consumer unit. There are about five percent more consumer units than households in the country. The Economy pages mention this where it matters.

Daytime population

An estimate of how many people are in an area during the working day, as opposed to how many sleep there. A downtown has a daytime population many times its resident population, and a bedroom suburb has the reverse. MarketGround builds its daytime figure from where jobs are, where workers live and a modeled day and night surface, and shows the two as a day to night ratio.

Drive time

See travel time area.

GeoJSON

A plain text file format for shapes on a map, which most mapping and GIS software can read and write. MarketGround can export a project's areas as GeoJSON and can read GeoJSON you upload.

Gravity model

A way of estimating which of several competing businesses a resident is likely to use, on the idea that people prefer nearer and larger options. MarketGround's competition and market share figures use one, with travel time as the distance. The methodology page says how it is set up.

Index

A figure expressed against a reference that is set to 100. An index of 120 means 20 percent above the reference, and 80 means 20 percent below it. MarketGround uses indexes so that a reader can judge a figure at a glance without knowing what is normal. On the analysis page the reference is usually the metro or the nation, and the page says which.

Isochrone

The technical name for a travel time area, from the Greek for "equal time". The edge of an isochrone is every point you can reach in the same number of minutes.

Jobs

Places of work, counted where the work happens rather than where the worker lives. MarketGround's job figures come from the Census Bureau's LODES data, which reports jobs by block and by industry. An area with many jobs and few residents is a workplace district.

LODES

The Census Bureau's Longitudinal Employer-Household Dynamics Origin-Destination Employment Statistics, which report, for every block, the jobs located there, the workers who live there, and the pairs of home and work blocks. MarketGround reads it for jobs by industry and for the daytime population.

Margin of error

The range within which a survey figure probably sits. Because the ACS asks a sample of households rather than everyone, a figure such as "2,340 households" is an estimate, and the Census Bureau publishes with it a margin of error, such as "plus or minus 210", at a 90 percent confidence level. That means that if the survey were repeated many times, nine times in ten the true figure would fall inside the range. MarketGround shows the margin on every survey figure on a paid plan and combines margins correctly when it adds figures up.

Median

The middle value in a list, with half the values above it and half below. Median household income is the income of the household in the middle, which is why it is not pulled upward by a few very rich households the way an average would be. The Census Bureau publishes medians for whole block groups, and MarketGround rebuilds a median for your exact area from the income brackets, which the methodology page explains.

Metro

A metropolitan statistical area, which the federal government defines as a core city and the counties around it that are tied to it by commuting. Dallas-Fort Worth-Arlington is one metro of eleven counties. MarketGround uses the metro as the usual reference for benchmarks and indexes, because it is the market a site competes in.

Pin

A marker you drop on the map at a point of interest, such as a competitor or a candidate corner, with a note attached. Pins belong to a project and appear on its map and in its report. They are part of the Pro and Team plans.

Polygon

A shape you trace on the map corner by corner, so that it follows the blocks you care about rather than being a circle. Double-click to finish one.

Project

A folder for the areas, pins and uploaded sites that belong to one piece of work. A project has a name, keeps its areas on the map, and has a full analysis page and a report of its own. The free plan includes one project and the paid plans include as many as you need.

Radius

The distance from a center point to the edge of a circle. A radius area is a circle drawn around a point you choose, with the radius in miles, kilometers or meters.

Rings

Several areas around one point at increasing distances or travel times, such as 1, 3 and 5 miles, shown together so that you can see how the figures change as the area grows. Rings are part of the Pro and Team plans.

Tract

A census tract, a geography larger than a block group and smaller than a county, holding about 4,000 people. Many government programs are defined by tract, which is why the Economy tab's designations and some other figures are reported by tract. A tract can be used as an area on the Pro and Team plans.

Travel time area

The area you can reach from a point within a set number of minutes by car, on foot, by bicycle or by public transit, following the real roads and timetables. Its edge is ragged because it follows the network, so a ten-minute drive reaches further along a highway than through side streets. Travel time areas are part of the Pro and Team plans. The technical name is isochrone.

ZIP code area

The Census Bureau's approximation of a postal ZIP code as an area on the map, called a ZCTA. Postal ZIP codes are routes for delivering mail and do not have exact edges, so the Bureau builds an area from the blocks whose addresses mostly share a ZIP code. MarketGround calls these ZIP code areas and can use one as an area on the Pro and Team plans.