Validating research data

Using Checklists

You can optionally show a check mark in the list of data items, and show a check list for data items. This can be used to quickly view which data items are complete (if you need to capture data from multiple sources) or whether items are in the right format.

Checklists look trivial, but are actually very powerful as they give quick insights in dataset issues. Missing these issues until after the study is done can be super expensive.

Checklists are written to ei-metadata.json and are automatically being picked up by the UI.

Checklists are driven by the metadata for a data item. Set the ei_check metadata item to either 0 or 1 to show a check mark in the list. Set an ei_check_KEYNAME metadata item to 0 or 1 to show the item in the check list.

To query for items with or without a check mark, use a filter in the form of:

metadata->ei_check = 1

To make it easy to create these lists on the fly you can set these metadata items directly from a transformation block.

Example

For the reference design described and used in the previous pages, the combiner takes in a data item, and writes out:

1. A checklist, e.g.:

   • ✔ - PPG file present

   • ✔ - Accelerometer file present

   • ✘ - Correlation between Polar/PPG HR is at least 0.5

2. If the checklist is OK, a combined.parquet file.

3. A hr.png file with the correlation between HR found from PPG, and HR from the reference device. This is useful for two reasons:

   • If the correlation is too low we're looking at the wrong file, or data is missing.

   • Verify if the PPG => HR algorithm actually works.