CEI vs NPS: the Cavefish Emotional Index and Net Promoter Score
Net Promoter Score turns one question into one number. The Cavefish Emotional Index (CEI) reads what people actually said - and shows who is angry, who has given up, who is about to leave, and what to fix first. Keep NPS as the headline. Use the CEI to decide what to do about it.
Net Promoter Score and NPS are registered trademarks of Bain & Company, Inc., NICE Systems, Inc. and Fred Reichheld. The NPS method described here is the standard published calculation.
Two people who both answer four
“Third time I’ve chased this refund. Sort it out.”
CEI: Angry, still invested. Fix the specific thing and tell them it’s fixed - they stay.
“It’s fine. I don’t really expect much any more.”
CEI: Resigned, at the door. Polite, quiet, and the one who leaves.
To NPS they are the same number. They need opposite things doing - and by the time a response becomes a score, the difference has been thrown away. Illustrative example.
Side-by-side comparison
| Feature | Net Promoter Score | Cavefish Emotional Index |
|---|---|---|
| What it reads | One answer: “How likely are you to recommend us?” (0-10) | What people actually said, in their own words |
| Scale | -100 to +100 | 0 to 100, higher is healthier - banded Strong, Good, Watch, Act |
| How it is built | % promoters (9-10) minus % detractors (0-6) | Five readings: advocacy, goodwill, engagement, drive, assurance |
| Someone who answers 4 | A detractor - the same as a 0 or a 6 | Angry, resigned, unsure, flat or given up - each needing a different fix |
| Who is about to leave | Not shown | Banded: at the door, slipping, still in it, anchored |
| Where it tells you to start | The theme most detractors raised | The theme whose people sit furthest below everyone else |
| Needs a survey question | Yes | No - reads comments, reviews, complaints and transcripts you already have |
| Customers and colleagues | NPS for customers, eNPS for employees | One scale for both, worded for each |
| Across the business | Customer experience | The same scale in Sales, Marketing, Comms and Culture |
| Industry benchmarks | Widely published | Describes your people, tracked over time and across your own teams |
| UK data residency / ICO | Depends on your survey platform | UK by default - ICO ZB915633 |
The five readings behind the CEI
Each response is read for its emotional content and placed on five scales, each 0 to 100 with higher healthier. The CEI is their average across everyone, in the same four bands every EchoDepth module uses: Strong (80+), Good (60-79), Watch (40-59) and Act (below 40).
Whether they have anything good to pass on.
How much hostility is in what they said - higher means less.
Whether they are still invested, or have resigned themselves to it.
Whether they are still trying to fix it themselves.
Whether they know where they stand - higher means less unease.
Your detractors are not one problem
NPS reports detractors as a single percentage. The CEI splits them by what is actually wrong, because each kind needs a different response:
Something specific went wrong for them. Find it, put it right, and tell them it is put right.
They have reported it before and nothing changed. Fix one known problem and say so.
They do not know what happens next. This is a telling-people problem, not a fixing problem.
Nothing here is worth telling anyone about. There is no good moment to pass on.
They are no longer trying to fix it themselves. The cheapest wins are here, and they expire.
Who looks like leaving
The people who leave are rarely the loudest. Anger is deliberately not used to judge leaving risk - angry people are still arguing with you. The CEI bands each person by resignation and drive instead. These are bands, never a percentage chance: nobody in a feedback file has a leaving outcome attached to them yet.
Stopped expecting anything and stopped asking. Likely to go at the next chance to switch.
Still here, expecting less each time. The group an action this quarter still reaches.
Complaining, and still invested enough to do it. The cheapest people to keep.
Has something good to say. Something keeps them.
Where each one tells you to start
A score-led reading chases the theme the most detractors mentioned, because a score counts heads. The CEI ranks each theme by how far below everyone else the people who raised it sit. The two orders often disagree - and when they do, the CEI is pointing at the smaller group that is closer to leaving. When they agree, that is worth knowing too.
When to use the CEI
When NPS is the right tool
The key difference in one sentence
NPS counts heads. The Cavefish Emotional Index measures how far down the people are, why, and who is about to leave.
“We can now understand the effect of our training over time - how understanding and confidence have shifted - without archaic paper forms and surveys.”
Questions
What is the Cavefish Emotional Index (CEI)?
The Cavefish Emotional Index is a 0 to 100 score of how people feel, read from what they actually said - open survey comments, reviews, complaints, call transcripts. It is built from five readings (advocacy, goodwill, engagement, drive and assurance), arranged so that higher is healthier, and reported in four bands: Strong (80+), Good (60-79), Watch (40-59) and Act (below 40). Every EchoDepth module - Sales, Marketing, Comms and Culture - reports on the same scale and bands.
What is the difference between CEI and NPS?
Net Promoter Score asks one question - how likely are you to recommend us, from 0 to 10 - and reports the percentage of promoters (9-10) minus the percentage of detractors (0-6). Its arithmetic keeps only which of three buckets each person fell into. The CEI reads the words behind the score, so it can tell apart two people who would both answer four: one angry and still invested, one who stopped expecting anything. They need opposite things doing. NPS counts heads; the CEI measures how far down the people are and why.
Does the CEI replace NPS?
No. NPS is a widely understood headline number that boards track and benchmark. The CEI works on the open comments you already collect alongside it, and explains the number: which detractors are angry, which are resigned, who is close to leaving, and which theme to fix first. Most teams keep NPS as the headline and use the CEI to decide what to do about it.
Can EchoDepth produce an NPS if we never asked the recommend question?
Yes, as an estimate. EchoDepth infers where each response would sit on the 0 to 10 scale from its sentiment and emotional content, and labels the result as inferred everywhere it appears. If your upload includes a real recommend score, that is used instead. The CEI itself is never inferred - it is read directly from what people wrote or said.
Does the CEI work for employees as well as customers?
Yes. The same five readings and four bands apply to pulse surveys, engagement survey comments and exit feedback, with findings worded for colleagues rather than customers. It is the measure the EchoDepth Culture module uses in place of eNPS. EchoDepth reads messages, not people: it scores what was written or said, not individuals.
See what your NPS comments are really saying
Send an export of your survey comments and receive a CEI read - who is angry, who has given up, who is about to leave, and where to start.