Mediators

Name the in-between step the cause has to run through to reach the outcome. Not what else could explain the link, and not what changes its strength, but the actual chain: cause acts on this, and this acts on the result.

Name the in-between step the cause has to run through to reach the outcome. Not what else could explain the link, and not what changes its strength, but the actual chain: cause acts on this, and this acts on the result.

Example

In the teenager case, you write the middle link as lost sleep: the phone in the bedroom pushes bedtime past midnight, and short sleep sours the mood. That gives you something to measure directly, so you track bedtime and hours slept for two weeks, not just mood.