How reliable are the data?

How reliable are the data; what problems remain?

Wise users understand that data are collected by people and organizations that have their own plans and purposes. The Data_Quality_Information is not intended to put authors to shame, but is there to permit them to explain to users what sort of accuracy, completeness, and internal consistency they should expect to find in the data. Don't sweat it, just tell it like it is.

What can you say about the accuracy of the observations?
```
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report:  Information and advice
```
The report should include a summary of the processes by which the attribute data have been reviewed or tested, including results.
Optionally, if you have statistics on the accuracy of the attributes, include for each statistic the following elements:
```
    Quantitative_Attribute_Accuracy_Assessment:
      Attribute_Accuracy_Value:  A statistic
      Attribute_Accuracy_Explanation: What the statistic means
```

How accurately are the geographic locations known?

Data_Quality_Information:
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:  Information and advice

This report should include a summary of the processes by which the geographic positions have been reviewed or tested, including results.
Optionally, if you have statistics on the accuracy of the locations, include for each statistic the following elements:

      Quantitative_Horizontal_Positional_Accuracy_Assessment:
        Horizontal_Positional_Accuracy_Value:  A statistic
        Horizontal_Positional_Accuracy_Explanation: What the statistic means

If data vary in depth or height, how accurately is vertical position known?
This is like Horizontal_Positional_Accuracy; just swap "Vertical" for "Horizontal" in all of the element names:
```
Data_Quality_Information:
  Positional_Accuracy:
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report:  Information and advice
```
This report should include a summary of the processes by which the elevations or depths have been reviewed or tested, including results.
Optionally, if you have statistics on the accuracy of the elevations or depths, include for each statistic the following elements:
```
      Quantitative_Vertical_Positional_Accuracy_Assessment:
        Vertical_Positional_Accuracy_Value:  A statistic
        Vertical_Positional_Accuracy_Explanation: What the statistic means
```

Where are the gaps in the data? What is missing there?

Data_Quality_Information:
  Completeness_Report:  Information and advice

Do the observations mean the same thing throughout the data set?
- What contextual factors should be considered by someone who wants to understand the data?
- Did the instrumentation or calibration change while observations were being made?
- Does it matter who made the observations? If so, did more than one person make observations?
```
Data_Quality_Information:
  Logical_Consistency_Report:  Information and advice
```
If you have contact information for people who did some of the data collection or data processing but aren't authors, you can include that contact information in the Process_Contact section of the Lineage (see Are the data original observations of the authors? and How were the source data modified?).

Next:	How can someone get a copy of the data set?
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