Because versus since: name the cause.
By Adam Frick · Illustrated draftDid the new method cause the variation?
The laboratory changes its method and the results begin to vary. A neat sequence, but have you established an explanation? I want “because” to make a causal claim visible, so the reader can ask what supports that claim. For a statement about timing, I prefer “since”. Changing the connector should make you check the evidence, not merely admire the smoother sentence.
See the supporting references.Watch the claim change.
Locate the change in time.
Constructed teaching exampleThe results have varied since the laboratory changed its method.
Method changed → Period with varying results
Make a causal claim explicit.
Constructed teaching exampleThe results have varied because the laboratory changed its method.
Method change → Claimed cause of the variation
Preserve the qualification.
Constructed teaching exampleThe instrument was chosen because the instrument is stable.
The instrument was chosen partly because the instrument is stable.
See the published wording.
This is one of the reasons why an electrical substitution radiometer was chosen, since it is inherently stable.
A grammatical sentence can still overclaim.
I give these words different teaching jobs because I want the relationship to be explicit. Cambridge also recognises causal “since”, and the NASA example uses that accepted construction. My preference is narrower than the grammar. When the evidence establishes only timing, replacing “since” with “because” strengthens the claim without strengthening the evidence.
References and evidence
Read the evidence and its limits.
NASA’s use of “since” is grammatical. Cambridge’s account of “since”[2] recognises both temporal and causal uses. My preference narrows the choice for a practical purpose. I want the connective itself to identify the relationship as far as possible, without asking context to do all the work.