Experience vs Expectations: The Science Behind How Customers Judge Experience

Experience is judged against expectations — not in isolation

Customer experience rarely fails in obvious ways. More often, it erodes quietly.

Scores remain steady. Complaints don’t spike. Operational metrics look acceptable. Yet customers become less forgiving, trust weakens, and switching feels easier than it did before. When this happens, the problem is rarely experience delivery alone — it’s the relationship between delivery and expectation.

Every customer judges an experience against a mental reference point: what they expected to happen. That expectation is shaped by past interactions, competitor behaviour, marketing promises, reviews, and even experiences in completely different categories. A banking app is no longer judged only against other banks, but against the best digital experiences customers encounter anywhere.

This is why customer experience is fundamentally relative. The same level of service can feel impressive, acceptable, or disappointing depending on where expectations sit at that moment. When delivery improves but expectations rise faster, customers don’t experience progress — they experience stagnation or decline.

Decades of behavioural and consumer research show that satisfaction, trust and loyalty are driven not by what happened in absolute terms, but by whether reality met, exceeded or fell short of expectations. This expectation–delivery gap explains why organisations can invest heavily in CX and still feel like they’re falling behind.

Understanding how customers form expectations, how they compare them to experience, and how those expectations change over time is essential to managing customer experience effectively. The sections that follow outline the science behind this process — and why it remains one of the most misunderstood dynamics in CX today.

What research shows: Across decades of consumer and service research, customer satisfaction is consistently explained by how experience compares to expectations — not by performance alone. The same experience can be judged positively or negatively depending on the reference point customers bring into it. (Oliver, 1980; Yi, 1990; Anderson & Sullivan, 1993; Schiebler, Lee & Brodbeck, 2025)

The expectation–delivery gap: a simple model that explains satisfaction

The relationship between expectations and experience has been studied for decades in psychology, marketing and service research. One of the most influential frameworks to emerge from this work is expectancy–disconfirmation theory.

At its core, the model is simple. Customers approach an experience with a set of expectations about what should or will happen. After the experience, they compare what actually occurred with those expectations. The result of that comparison — not the experience alone — shapes how the interaction is evaluated.

When experience performs better than expected, customers experience positive disconfirmation. When it performs worse than expected, they experience negative disconfirmation. When experience aligns closely with expectations, customers perceive confirmation, even if the experience itself was unremarkable.

Crucially, satisfaction is not driven by performance in isolation. Two customers can receive the same service and walk away with very different evaluations if their expectations differ. Likewise, the same organisation can deliver a consistent experience while customer sentiment shifts as expectations rise or fall around it.

This is why experience scores can appear stable while loyalty weakens or complaints slowly increase. The experience itself may not have deteriorated, but the reference point customers use to judge it has moved. Without visibility into that shifting baseline, organisations are often left reacting to outcomes rather than anticipating them.

Understanding this expectation–delivery comparison is foundational to modern customer experience management. It provides a clearer explanation for why customer sentiment changes, and why traditional CX measures often struggle to surface early signs of risk.

What research shows: Disconfirmation and satisfaction are often so strongly correlated that they may not represent distinct psychological constructs in practice. When customers report satisfaction or dissatisfaction, they are typically expressing the outcome of the expectation–experience comparison. (Oliver, 1980; Yi, 1990; Schiebler, Lee & Brodbeck, 2025)

Method note: Tests for publication bias indicate that the true relationship between disconfirmation and satisfaction is unlikely to be overstated in the literature. In fact, evidence suggests the average effect may be underestimated due to missing large-effect studies. (Schiebler, Lee & Brodbeck, 2025; Stanley et al., 2015)

Assimilation and contrast: why small gaps feel small and big gaps feel huge

The gap between expectation and delivery does not translate into satisfaction in a straight line. How customers perceive that gap depends on how far experience deviates from what they expected — a dynamic explained by assimilation and contrast effects.

When experience falls close to expectations, customers tend to assimilate what happened toward what they expected. Minor issues are downplayed, inconsistencies are rationalised, and the experience is remembered as “basically what I thought it would be.” In these cases, expectations act as an anchor that pulls perception toward them.

This is why small service failures often go unnoticed, and why incremental improvements can struggle to register. When delivery stays within a customer’s tolerance range, perception bends to protect the expectation rather than amplify the difference.

Some theories suggest that when the gap between expectation and delivery becomes large, a contrast response can occur. In these cases, the difference may feel amplified — making experiences seem disproportionately better or worse than the objective change alone would suggest.

What research shows: While contrast effects are theoretically plausible, large-scale evidence suggests assimilation is the dominant pattern in customer experience evaluation. Contrast effects appear less consistently and may depend on extreme mismatches or nonlinear conditions that are difficult to observe in typical CX measurement. (Anderson, 1973; Oliver & DeSarbo, 1988; Schiebler, Lee & Brodbeck, 2025)

In practice, evidence for contrast effects is less consistent than for assimilation, and may depend on specific conditions, such as extreme mismatches or nonlinear responses that are difficult to observe in typical CX measurement. What is clear is that customer reactions are often non-linear: long periods of tolerance can be followed by sudden shifts when expectations are clearly violated.

For CX leaders, this means that managing experience is not just about closing gaps, but understanding where those gaps sit relative to customer expectations. Staying just below expectations can quietly erode goodwill, while clearly exceeding them can have an outsized positive impact.

Research call-out: A large meta-analysis of expectancy–disconfirmation research finds a strong overall assimilation pattern—higher expectations tend to be associated with higher satisfaction—while finding little direct empirical evidence for contrast effects in the existing literature. The same meta-analysis notes contrast effects may still exist under specific (nonlinear) conditions—especially when expectation–performance gaps are extreme—but these nonlinear predictions have received limited empirical testing to date. (Schiebler, Lee & Brodbeck, 2025)

When expectations move: how the CX goalposts keep shifting

Customer expectations are not fixed. They operate as a moving reference point that customers use to judge experience, shaped by past interactions, competitor behaviour, and broader shifts in service standards. What felt impressive last year can feel merely adequate today, even if nothing about delivery has changed.

Research suggests that expectations influence not only how experiences are judged, but even how they are remembered. What customers believe they expected can be reshaped after the experience itself, particularly when expectations are measured retrospectively. This makes expectation drift difficult to detect using point-in-time CX metrics alone.

What research shows: Expectations operate as reference points rather than fixed benchmarks. When measured after the fact, recalled expectations are vulnerable to hindsight and halo biases, making early shifts in how customers judge experience difficult to observe. (Kahneman & Tversky, 1979; Oliver, 2010; Schiebler, Lee & Brodbeck, 2025)

This dynamic helps explain why customer experience performance can quietly deteriorate without obvious failures. As competitors improve, digital norms shift, or category standards rise, customers recalibrate what good looks like. An organisation that delivers consistently may still fall behind if delivery does not improve at the same pace as expectations.

The result is a form of hidden risk. Satisfaction scores can remain stable while tolerance narrows, forgiveness declines, and customers become more sensitive to disruption. By the time dissatisfaction becomes visible in surveys or churn data, the reference point customers use to judge experience may have already moved.

For CX leaders, the implication is clear: managing experience requires visibility not just into what customers experience, but into how the benchmark they use to judge that experience is changing. Without insight into that shifting baseline, organisations are left reacting to outcomes rather than anticipating them.

What this means for CX leaders

Viewing customer experience through the lens of expectations changes how improvement efforts are prioritised and evaluated. It highlights why focusing on delivery alone is often insufficient, and why some CX initiatives fail to move sentiment even when operational performance improves.

First, managing customer experience requires managing expectations as well as execution. Clear communication, transparent policies, and consistent signalling all shape the reference point customers use to judge experience. Over-promising or allowing expectations to inflate unchecked increases the risk of negative disconfirmation, even when delivery is objectively strong.

Second, CX leaders need to look beyond point-in-time scores. Stable satisfaction or NPS results can mask a widening expectation gap, particularly in competitive or fast-moving categories. Early warning signs often appear in qualitative signals, recurring friction themes, or subtle shifts in the language customers use to describe their experiences.

Third, prioritisation improves when experience gaps are viewed relative to expectations. Not every issue has the same impact. Problems that pull experience below expectations deserve immediate attention, while areas where delivery already exceeds expectations may represent opportunities to reinforce or defend advantage.

Finally, expectation-based thinking supports more realistic measurement of progress. Improvement should be assessed not just by whether scores rise, but by whether experience is keeping pace with changing customer standards. This perspective helps organisations avoid false confidence and focus investment where it protects the most value.

Commercial evidence: Meta-analytic research shows customer satisfaction is strongly associated with retention, word of mouth, spending, price tolerance, and firm-level financial performance. These effects persist across industries and economic conditions. (Mittal et al., 2023; Anderson et al., 1994; Fornell et al., 2006)

Why this matters at an industry level

While expectation–delivery dynamics are experienced individually, they also operate at an industry level. As category norms shift and competitors raise standards, customer expectations tend to move in parallel, changing how experience performance is judged across the market.

CXBI was designed to observe this dynamic in motion. By analysing large volumes of real-world customer feedback and benchmarking performance against long-term industry baselines, CXBI provides an outside-in view of whether experience delivery is keeping pace with changing expectations over time.

Rather than focusing on isolated interactions or internal scores, CXBI helps surface sustained shifts in customer experience performance at a category level. This makes it easier to spot emerging risk, understand where experience is improving or slipping, and place individual CX initiatives in a broader market context.

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Glossary: key concepts explained

Expectations
The beliefs customers hold about what should or will happen during an experience, shaped by past interactions, competitor behaviour, marketing promises, reviews and broader category norms.

Delivery (perceived performance)
How customers perceive what actually happened during an interaction, which may differ from operational or internal measures of performance.

Disconfirmation
The comparison between expectations and perceived delivery. Positive disconfirmation occurs when experience exceeds expectations, negative disconfirmation when it falls short, and confirmation when it aligns closely.

Definition note: Satisfaction is commonly defined as a judgment that a product or service provides a pleasurable level of consumption-related fulfilment, including under- or over-fulfilment relative to expectations. (Oliver, 1980; Mittal et al., 2023)

Assimilation
A psychological effect where small gaps between expectations and delivery are downplayed, with customers adjusting their perception of the experience to align with what they expected.

Contrast
A psychological effect where large gaps between expectations and delivery are exaggerated, making experiences feel disproportionately better or worse than the objective difference might suggest.

Expectation–delivery gap
The distance between what customers expect and what they perceive was delivered, which plays a central role in shaping satisfaction, trust and loyalty over time.