You can enter a county in the box under the Participation Rate legend and click "Go". This will zoom to that county, display a list of tracts on the right side of the map, and highlight those tracts in orange on the map.

The list of tracts will depend on the Participation Rate that you enter with the county name. If it's too low (30%, for example), the map might not show any tracts. If it's 100%, the map and list will show the top 20 tracts with rates of 100% or less.

Yes, just click on the column on the right called "Participation Rate". It first starts out sorted low to high. If you click once on the column header, the list will switch from high to low. And the map will show those tracts in orange.

This means you can use the list to see the worst-performing tracts in your county, or the best. And if these tracts are concentrated together, the map will show them as clusters of orange-highlighted tracts.

Yes, just zoom in on the map (use the zoom slider on the left, or double-click on the map, or hold the Shift key while drawing a "box" on the map) and tracts will automatically appear.

If you click on the map, a pop-up window will appear that shows the latest 2010 participation rates compared with the rate for 2000. It also shows a link to the Census Bureau's Take 10 map (at http://2010.census.gov/2010census/take10map/).

You can use the transparency slider above the legend for the Participation Rates. As you slide it to the right, the participation rate shading becomes more transparent, revealing what's beneath.

You can also uncheck the box next to the "Census 2010 Participation Rate" option, and that will "turn off" the participation rate color shading completely.

If you select the "More..." tab under the website's logo, you can check the box next to "Participation rate in 2000" to display the rates from a decade ago. This will be displayed as an overlay on the 2010 participation rates. You'll need to "turn on and off" the 2000 layer to compare.
Also, when you click on the map, the popup window displays the 2000 and 2010 participation rates for the state, county, or tract in which you clicked.

Click the "Clear" button under the zoom slider. This will remove the popup window and the blue highlight.

No, but you can make it transparent. See the screen shots below.

States are shaded only when you're zoomed out very far. But you can check the "County" or "Metro" option above the legend to display maps for these areas instead.

As you zoom in, eventually the "Tract" option will be available. Once you click it, the map will change to display hard-to-count tracts in that area

The Census map uses Google Maps to show streets, parks, and other reference features. By default, we display the "terrain view" from Google Maps. If you zoom in as far as you can, Google doesn't provide a terrain view at this scale. But you can easily switch to the Google Maps "map view" by clicking the "MAP" button in the upper right corner of the map. Then the map will change from this:

... to this:

Yes, just click the "US graphic" above the zoom slider.

We purposefully grayed out the basemap so its colors wouldn't conflict with the color shading for Census tracts, counties, etc.
We think Google Maps uses great colors too, but the purpose of the Census 2010 Hard To Count map isn't for transportation routing or map search, per se, it's for pinpointing hard to count neighborhoods so you can plan your outreach efforts. Therefore, we wanted to emphasize these colors rather than the streets and other basemap features.

There are several ways to zoom in and out. These are:
a) Click the "In" or "Out" buttons on the zoom slider [see image at right];
b) Move the slider up or down;
c) Double-click on the map (this will zoom in one level); or
d) Hold down the shift key on your keyboard and simultaneously use your mouse to "draw a box" on the map. When you let go off your mouse button, the map will zoom in to the area of the box.

There are likely two possible reasons:

1. If the maps are working ok, that means you probably live in an area that the Census Bureau considers relatively easy to count. The hard-to-count areas (Census tracts with a HTC score above 60) are relatively concentrated across the country --> 80% of the tracts nationwide have HTC scores of 60 or less, so many areas won't be color-shaded on the maps.
2. The other reason is that there may be a problem with the website. If you're pretty sure you live in a hard-to-count area, please contact us and we'll look into the problem.

An example of this situation is the address "1 West Kennett Dr, Terre Haute, Indiana". See the screen shot below.

In this case, the map displays a red marker in the right place, but tract is so large (the area highlighted in blue) that the center of the tract is far away. The popup window is "anchored" to the center of the tract. Zoom out a bit to see the extent of the tract in relation to your address.

No, the map only shows hard-to-count data and shaded maps for Census tracts, counties, metropolitan areas, and states.
When you enter a ZIP Code in the Address search box, the map will zoom to the center of the ZIP Code and highlight the Census tract that happens to be located at that central location. The popup window will display information for that tract.
You can also add a ZIP Code layer to the map for reference purposes - it's available once you've zoomed in close enough, and will display ZIP Code boundaries with the ZIP Code ID displayed on the map. But you can't click on a ZIP Code to get detailed info.

This mapping site uses a threshold score of 61 or higher to identify hard-to-count census tracts. (The Census Bureau's Tract Level Planning Database assigned an HTC score of 0 to 132 for all tracts nationwide.) The cutoff score of 61+ identifies roughly the top 20% of all tracts nationwide that are the hardest-to-count. We used a threshold to facilitate creating individual map layers for the detailed hard-to-count characteristics at the state, metro area, county, and tract levels (just over 100 map layers). Although a threshold is somewhat arbitrary, it provides a consistent standard nationwide so anyone using these maps will be comparing "apples to apples."

But there are two important things to remember as you view the maps, in the context of this threshold:

1. There are areas with HTC scores of 60 or less that still may pose enumeration challenges, though they're likely not as hard to count as areas with higher scores. But you can simply click on any area of the country to obtain demographic characteristics regardless of the hard-to-count score. So if you've zoomed to an area on the map that isn't shaded but you still think it will be hard to count, just click on the map to see the population and housing data for that area to incorporate this information into your outreach strategy.
2. At the tract level, we assume that for each tract with an HTC score above 60, the entire tract population is considered hard-to-count. (The Census Bureau's hard-to-count analysis was done at the tract level and did not differentiate the population within tracts.) Note that Census tracts generally contain between 1,500 and 8,000 people. Tracts covering "Group Quarters" -- such as military barracks, prisons, and college dormitories (on-campus housing) -- might have more people.

The Census 2010 Hard To Count map focuses on mapping the Census Bureau's hard-to-count population analysis. The Bureau analyzed 12 population and housing variables from the 2000 Census, so we've mapped these categories plus one more: the hard-to-count population itself.

But we also show more information from the 2000 Census when you click on the map. A popup window is displayed, with several tabs for more information:

• The "Census Links" tab displays links to the Census Bureau's FactFinder profile for the area you've clicked in (from the 2000 Census, and from the more recent 2006-2008 American Community Survey); and
• The "HTC Stats" tab lists the population and housing counts and percentages for each specific hard-to-count category, but also provides race & ethnicity data.

The 12 population and housing characteristics evaluated by the Census Bureau correlate most closely with low participation in 2000 Census. According to the Census Planning Database documentation:

"The variables included in the Tract Level Planning Database With Census 2000 Data (also called the planning database, or PDB) were guided by extensive research conducted by the U.S. Census Bureau and others to measure census coverage and to identify reasons people are missed in the census (de la Puente, 1993). The variables include housing indicators (percent renters, multi-units, crowded housing, lack of telephones, vacancy, [and public assistance]) and person indicators (poverty, not high school graduate, unemployed, complex households, mobility, language isolation). Other operational and demographic data are also included (such as race/ethnic distributions). Using the 1990 Census as the initial source, a database containing these variables was developed for all tracts in the country for use in the planning, implementation, and evaluation of Census 2000 (U.S. Bureau of the Census, 1999). The PDB contains hard-to-count (HTC) scores which summarize the attributes of each tract or block group in terms of enumeration difficulty."

When you hover your mouse over each color-coded header on the left side of the map, you'll see a window appear with context about why each category is important (see screen shot at right).

For the county, metro, and state-level maps, the shading for hard-to-count population displays the percent of each area's total population living in hard-to-count tracts (i.e., tracts with HTC scores above 60).

But when the map changes to show Census tracts, it only displays the tracts with HTC scores above 60.

So it wouldn't make sense to use color shading to show the percent of the tract's population in hard to count tracts; the entire tract population (100%) is considered hard to count.

Instead, we shade the tracts by color to represent the actual hard-to-count scores from the Census Bureau. We use the same color shading as the population percents to be consistent within this category. When you zoom in close enough, you'll see a number displayed on the map within each tract. That's the actual HTC score.

Remember that the color-shading on the maps represents percent of the total population in hard-to-count tracts (or percent of the hard-to-count population in poverty, facing language obstacles, etc). A large portion of a given area's population may be hard to count, but the total number of people in hard-to-count tracts may be relatively small. You can compare percents vs. total numbers by adding the "graduated circles" map overlay for any given HTC characteristic.

For example, the map at right shows counties along the Mississipi River, shaded by percent population that's hard to count.

But in the map below, we've "turned on" the green circles -- which represent total number of hard to count residents by county.

You can see that some counties shaded dark have relatively small circles on them, and some have larger circles. The counties with large circles and shaded dark red have both: a large number of hard-to-count residents, who also represent a large percent of the county's population.
You can use both types of maps to plan your outreach. Darker shaded areas mean you'll that you're more likely than not to find people who meet the characteristic you've mapped in these areas. Large circles mean that there'll be lots of people who meet the characteristic, regardless of whether a small or large percent of the area's population meets the characteristic.
Also, once you've zoomed in to your area of interest you should do 3 more things:

1. click on each area to display population statistics (this will provide the exact numbers and percents, rather than the color shading which just gives you a range);
2. change the map to display other characteristics (total hard-to-count population is important, but the other map types will show you concentrations of people who are renting, or who have difficulty speaking English, or who are in poverty, or who have low education levels, etc.); and
3. zoom in close enough so you can display tract-level maps. This will show you exactly where the hard-to-count tracts are concentrated. An entire county will be shaded according to the percent of its total population considered hard to count. But the HTC population may be in only one or two areas within the county. This is often true of counties that are generally rural or suburban but have an urban center.