Focus vs concentration: why Sarenica tracks both
Concentration tells you what is happening in the next minute. Focus tells you what happened across the last block. They look the same in the abstract and behave nothing alike in the data.
- Concentration is the per-minute reading; focus is the sustained pattern across a session.
- A high concentration moment does not mean a focused hour, and vice versa.
- Weekly reports lean on focus, but concentration is what catches a bad block in real time.
A single word does two different jobs
In casual use, focus and concentration mean the same thing. In tracking data they behave nothing alike, and treating them as synonyms is one of the easier ways to misread a report.
Sarenica records both because they answer different questions. Concentration answers *"what is happening right now in this minute."* Focus answers *"what kind of block was this."* Same camera; different time horizons; different decisions to make off them.
Concentration is a snapshot
Concentration is a per-minute score derived mostly from camera signals: gaze direction, blink pattern, micro-movements, head-pose stability. It moves fast. A good minute can climb to 80, a distracted minute can drop to 20, all within the same hour.
That is exactly the property that makes it a bad verdict on the session. It is a snapshot, not a summary. The live readout in the desktop app shows concentration; the daily summary leads with focus. Different views, different jobs.
Focus is the continuity score
Focus is computed across a window of minutes. It captures continuity: how often per-minute concentration stayed in a usable range, how stable head-pose was over time, how much of the session went to actual engaged work versus low-engagement passive presence.
A minute can spike to perfect concentration and the focus score for that session can still be mediocre, because focus is sensitive to the *gaps between the spikes.* That is what makes it the right signal for "was this a good block."
Why one peak does not save a session
Almost everyone has high-concentration minutes scattered through bad sessions. The brain locks in for ninety seconds, drifts, locks in again. That is normal.
Focus filters out the spikes. Twelve high-concentration minutes spread across sixty minutes of a fragmented session means focus is low even though the peaks looked great. The reverse is also true: a long steady, slightly less intense session can score lower on peak concentration but higher on focus, because the continuity is the thing.
How they show up in your weekly report
Weekly reports lean almost entirely on focus, because the question is "what kind of work blocks are working for me." Concentration shows up underneath — as input into focus, and as one of the per-minute signals feeding fatigue burden.
A report finding that says "30-45 minute sessions show lower focus" usually means the late minutes stopped sustaining concentration. Not that you were never focused. Same data; different lens.
- Concentration → "what is happening in the next minute."
- Focus → "what kind of block was the last hour."
- Weekly report → how focus distribution changes by hour and session length.
