Definition
CSAT, or customer satisfaction score, is the share of survey respondents who rate a specific interaction as satisfied. It usually comes from a single question asked right after a call, scored on a five-point scale.
How CSAT works
CSAT asks one question about one interaction, such as “How satisfied were you with this call?” Customers answer on a scale, most often 1 to 5. The score is usually the percentage of responses that are 4 or 5.
CSAT = responses of 4 or 5 / all responses x 100
Some teams report the mean rating instead, such as 4.3 out of 5. The two numbers are not interchangeable, and neither is better. What matters is that a team picks one and keeps it, because a change of method looks like a change in customer happiness.
The weakness is who answers. Only a fraction of customers respond, and those who do are often the pleased and the angry, not the people in between. A score built on 5 percent of calls says little about the other 95 percent. Report the response count and the response rate next to the score, and compare scores only between groups of calls of the same type, because a billing dispute and a store hours question do not score alike.
Why it matters for voice agents
CSAT is the quickest check on whether callers accept the agent, and it is the per-call counterpart of NPS, which measures loyalty to a company. For an agent, the useful comparison is automated calls against human-handled calls of the same type, because satisfaction depends heavily on the topic.
A voice agent can also run the survey itself, at the end of the call, which tends to raise the response rate over a link sent afterward. That has a cost. A caller asked to rate the agent while still on the line with it may answer to be polite, and a rating spoken to the thing being rated is not the same as an anonymous one. Treat the two collection methods as separate series and do not merge them.
Satisfaction also lags outcomes. A caller who was told “done” and later finds the problem still open will not be reflected. Read CSAT together with resolution rate and first call resolution.
Example
An illustrative week (invented numbers): 600 automated calls end with the survey, and 240 callers answer. 168 give a 4 or a 5.
CSAT is 168 / 240 = 70%, from a 40% response rate.