Direct answer: When the stated goal is intangible, choose short-term proxy metrics that plausibly sit on the causal path to the real goal, and pair them with a longer-term outcome metric that is at least directionally related to the goal, even if imperfect, then validate the proxy periodically with a direct (often qualitative or survey-based) check rather than trusting the proxy blindly forever.
Structured elaboration
- Short-term proxies: pick behaviors that a reasonable person would expect to correlate with the intangible goal, chosen for being measurable quickly. For "more meaningful social interactions," candidates include reply depth (a back-and-forth exchange rather than a single message), time between reciprocal messages (faster mutual engagement), or the diversity of people a user regularly interacts with (breadth of relationships, not just volume).
- Long-term outcome proxies: pick something that would plausibly move if the intangible goal is genuinely being achieved over a longer horizon, such as retention specifically among users who show high short-term-proxy activity versus those who do not, or a periodic survey question closely worded to the actual goal ("I feel more connected to people I care about because of this app").
- Validating the proxy: periodically run the direct check (a survey, a qualitative study) against the short-term proxy to confirm the proxy still tracks the real goal, since proxies can drift or be gamed even when chosen thoughtfully; if the proxy and the direct check diverge, trust the direct check and revise the proxy.
- Being honest about the limits: state clearly, when reporting on this feature, that the proxy metrics are proxies, not the goal itself, so stakeholders do not over-interpret a proxy movement as proof the intangible goal was achieved.
Worked example: For a feature intended to help people have "more meaningful social interactions," the team picks reciprocal-reply rate within 24 hours as the short-term proxy and 90-day retention among high-reciprocal-reply users as the long-term outcome proxy. Six months in, the team runs a survey asking users directly whether the app helped them feel more connected to people they care about, and finds the survey response correlates well with the reciprocal-reply proxy (users high on the proxy report feeling more connected at meaningfully higher rates than users low on it), which validates continuing to use the proxy as the day-to-day operating metric while reserving the survey as a periodic sanity check rather than something to run constantly.
Trade-offs and pitfalls: The main risk is picking a proxy that is easy to measure but only weakly related to the real goal (raw message volume, for instance, correlates poorly with "meaningful," since spam-like or transactional messaging can inflate volume without any of the intended value), and then optimizing hard against that proxy, which can actively make the real goal worse (a feature that maximizes message volume might crowd out fewer, higher-quality exchanges). The other pitfall is never running the direct validation check at all, so a proxy that quietly stopped tracking the real goal (or never did) goes uncaught indefinitely.
