Sample Selector
    Sample Selector is a tool for creating and editing
    samples, or groups of data you compare across—they're
    not "samples" in the statistical sense, but more like filters.
    
    By default, a single sample exists: "All Data". With the Sample
    Selector, you can create new samples to organize your data.
    
    You can use samples to:
    
        - Compare across conditions
- Narrow the scope of data analysis to a specific time range,
        set of students, problem category, or unit of a curriculum (for example)
        
A sample is composed of one or more filters, specific
    conditions that narrow down your sample.
    
    Creating a sample
    The general process for creating a sample is to:
    
    	- Add a filter from the categories at the left to the composition
        area at the right
- Modify the filter to select the subset of data you're interested 
        in, saving it when done
- View the sample preview table to see the effect of adding your filter,
        making sure you don't have an empty set (ie, a filter or combination
        of filters that exclude all transactions).
- Name and describe the sample
- Decide whether to share the sample with others who can view the
        dataset
- Save the sample
The effect of multiple filters
    DataShop interprets each filter after the first as an additional
    restriction on the data that is included in the sample. This is also known
    as a logical "AND". You can see the results of multiple filters in the
    sample preview as soon as all filters are "saved". 
    
     Read more 
    about the Sample Selector
 Read more 
    about the Sample Selector