04
Data access: test a safe sample and inspect its structure
A file appearing in Positron’s interface proves that the file was opened or displayed. It does not prove that the analysis read the intended file, interpreted its columns correctly, or applied the right filtering logic.
Start with a public or properly de-identified sample that has the same relevant structure as the research input. Put it in a documented test location and use an explicit project-relative path where practical. Confirm that the program reads that specific file, not a similarly named file left elsewhere on the remote host. For tabular data, inspect column names and types, missing-value handling, and the range of records relevant to the analysis. The checks should reflect the project’s design: a date field, identifier, measurement unit, or category may need a project-specific validation rather than a generic “data loaded” message.
For pandas-based workflows, compare the loading code with the pandas input and output documentation. That documentation covers supported input formats and reading behavior; it does not determine whether a particular study’s data are semantically valid. We therefore retain a small, safe test input and record the expected structure or a known intermediate result. If the actual output differs, stop and investigate the path, parsing options, data types, and transformations before using the study data.
The remote Mac adds practical details to record: where the sample is stored, whether the project uses a mounted location, and whether any path depends on a particular user account. Do not include access tokens, passwords, or restricted records in screenshots or handoff notes. A collaborator who cannot access the same path needs instructions for an approved alternative, not a copied credential.