VT Census Case Studies : Arlington County: Mapping Center

Created and last modified by molfe on 02 Jan 2016

Brief Overall Description of the Dataset:

The mapping center compiles and manages Arlington County's geo-coded data. In addition general shapefiles, they do create datasets and shapefiles for project specific tasks when asked.

Link: http://gis.arlingtonva.us/gis/gis_mappingcenter.asp

http://maps.arlingtonva.us/

Date Inventory Completed: 7/14/2015

Screening

  • Is the data collected opinion-based?
  • Is the data collection recurring (must be collected at least annually)?
  • Is there data available for 2013?
  • Is the data collected at the property or housing unit level?
  • Can we access the data by August 15th?

Purpose

  • What is the purpose of the organization collecting the data?

The GIS Mapping Center serves as the County's official mapping and analysis unit providing GIS consulting services,  cartographic expertise, aerial photo analysis, data maintenance, and data conversion support for all County agencies.  The GIS Mapping Center works with agency data owners to maintain corporate data including real estate, zoning, census, planimetric, street map, and street network to name but a few.  

  • Why is it collected and how does the organization use it?

Data is primarily disseminated to County government offices 

  • Who else uses the data?

The data is used throughout the county in addition to researchers, citizens, and businesses

  • Who do they sell the data to?

Researchers, citizens, businesses


Method

  • What is the data collection method? 

Unknown

  • What is the type of data collected? 

Geo Coded data

  • If designed, who created the questions?

  • What is the raw source of the collected data (prior to any aggregation)? 

Unknown


Description

  • What is the general topic of the data (1-2 words)?

GIS Data

  • What are the earliest and latest dates for which data is available?

Unknown

  • Is data collected and available periodically?

Yes (unknown frequency)

  • How soon after a reference period ends can a data source be prepared and provided? 

Data CDs are published annually in May or June.


Selectivity

  • What is the universe (e.g., population) that the data represents?

Arlington County


Accessibility

  • How is the data accessed? 

Data is disseminated to County government offices using a local area network and to the public using an interactive web-enabled mapping solution.  Standard, hard copy mapping products and digital data on CD ROM's are available to the public and to the business community.

Sent and downloaded through their FTP.

  • Is it open data?

Partially. For those that are, see: http://maps.arlingtonva.us/

  • Any legal, regulatory, or administrative restrictions on accessing the data source?

Nothing stated explicit. As agents of the state, we must protect the data like other county agencies.

  • Cost? - One time or annual or project based payment?

Current GIS Data is free

2015, 2013 GIS Data CD is $125

2011 2-Foot Interval Contour Data CD is $200 

2011 Orthophotography Data CD is $500 (2013 is available from the state)

We received data for free.

Does this dataset appear to meet our needs for the Census study? YES

Full Inventory

Description

  • Features
    • What is the temporal nature of the data: longitudinal, time-series, or one time point?

Longitudinal

    • Geospatial? If Yes, at what level?

Varies: address, parcel,  census block/tract, and/or lat/long

Projection: NAD83 Virginia State Plane North projection


Metadata

  • Is there information available to assess the transparency and soundness of the methods to gather the data for our purposes?

Unknown

To help access data from ESRI’s ArcGIS Desktop suite: http://gis.arlingtonva.us/docs/Instructions%20for%20Public%20Users%20of%20ArcGIS%20Server.pdf

  • Is there a description of each variable in the source along with their valid values?

Unknown

  • Are there unique IDs for unique elements that can be used for linking data?

Unknown

  • Is there a data dictionary or codebook?

Unknown


Selectivity

  • What unit is represented at the record level of the data source?

Unknown

  • Does this universe match the stated intentions for the data collection? If not, what has been included or excluded and why?

Unknown

  • What is the sampling technique used (if applicable)? 

Unknown

  • What was the coverage?

Unknown


Stability/Coherence

  • Were there any changes to the universe of data being captured (including geographical areas covered) and if so what were they?

Unknown

  • Were there any changes in the data capture method and if so what were they? 

Unknown

  • Were there any changes in the sources of data and if so what were they? 

Unknown


Accuracy

  • Any known sources of error?

Data are provided for reference purposes only. The data used isn't of survey quality and shouldn't be used for design or construction.

 

The geographic data for real estate properties reflects changes that were recorded through Dec. 31 of the previous year. Other geographic layers may reflect more recent changes, if any occurred.

  • Describe any quality control checks performed by the data’s owner.

Unknown

 

Accessibility

  • Any records or fields collected, but not included in data source, such as for confidentiality reasons)? 

Unknown

Disclaimer: The geographic data layers produced by the Arlington County GIS Mapping Center are provided as a public resource. The County makes no warranties, expressed or implied, concerning the accuracy, completeness or suitability of this data, and it should not be construed or used as a legal description. Every reasonable effort is made to ensure the accuracy and completeness of the data.

  • Is there a subset of variables and/or data that is must be obtained through a separate process? If yes, is there a separate legal, regulatory, or administrative restrictions on accessing the data source? Cost? - One time or annual or project based payment?

Unknown

Privacy and security

  • Was consent given by participant? If so, how was consent given?

Unknown

  • Are there legal limitations or restrictions on the use of the data? 

All products are copyrighted and may not be redistributed, resold or copied (except for backup or internal use).

Legal disclaimer and copyright: http://maps.arlingtonva.us/legal-disclaimer-copyright/

  • What confidentiality policies does the source have? 

As agents of the state, we are required to protect the data and confidentiality similar to other county employees.

 

Research

  • What research has been done with this dataset? (e.g., impact of policies, predictors of student success)
  • Include any links to research if provided:
  • List any other data use notes provided by the supplier.

 

Gaps/Concerns

  • Feasibility - can all jurisdiction levels provide the data (if applicable)?
  • Data ownership - a lack of clarity in legal guidance stemming from a lack of clarity with who owns digital data?
  • Data collection authority - what data is reasonably private and what constitutes unwarranted intrusion?
  • Describe any other notes you have or any gaps/concerns you see with this dataset: