Managers, planners, and organizational decision makers frequently evaluate options that differ across multiple attributes, yet observed choices often shift when the surrounding menu changes. Such context effects matter for product-line design, candidate screening, policy communication, and service bundling because they can change outcomes even when underlying objectives remain stable. This article develops a theory-centered account of contextual choice in which decision makers retain a stable utility function but interpret attribute information imperfectly. The framework shows why additional options can alter posterior beliefs about existing options when uncertainty in attribute perception is shared across alternatives. A tractable parametric case is used to clarify the mechanism, state the main comparative statics, and convert the formal results into testable implications for management research. The analysis shows how the same structure accommodates intransitivity, joint-separate evaluation reversal, the compromise effect, the attraction effect, and phantom decoy effects, while also preserving rational regularity when one option dominates another on all attributes. The article further explains how ternary-choice designs can be used to validate the model empirically. By translating a formal choice model into a management and planning context, the manuscript clarifies when context-sensitive choices are expected, when they should not occur, and how decision architectures can amplify, diagnose, or contain them.